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Optimization of the Czochralski method for InSb crystal ... - CUMC

Optimization of the Czochralski method for InSb crystal ... - CUMC

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Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong><br />

<strong>crystal</strong> growth<br />

<strong>CUMC</strong> 2008<br />

July 9 to 12<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

University <strong>of</strong> Ontario Institute <strong>of</strong> Technology<br />

July 9, 2008<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Outline<br />

1 Background<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

2 Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

The model<br />

Future work<br />

3 Summary<br />

In conclusion<br />

4 References<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Commercial uses include<br />

Thermal radiation detection<br />

Military gear<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Commercial uses include<br />

Thermal radiation detection<br />

Military gear<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Commercial uses include<br />

Thermal radiation detection<br />

Military gear<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Benefits and detriments<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Benefits <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Easy passage <strong>of</strong> electrons<br />

Detriments <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Difficult to grow with Cz technique<br />

Loose structure causes stress marks in large <strong>crystal</strong>s<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Benefits and detriments<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Benefits <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Easy passage <strong>of</strong> electrons<br />

Detriments <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Difficult to grow with Cz technique<br />

Loose structure causes stress marks in large <strong>crystal</strong>s<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Benefits and detriments<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Benefits <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Easy passage <strong>of</strong> electrons<br />

Detriments <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Difficult to grow with Cz technique<br />

Loose structure causes stress marks in large <strong>crystal</strong>s<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Benefits and detriments<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Benefits <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Easy passage <strong>of</strong> electrons<br />

Detriments <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Difficult to grow with Cz technique<br />

Loose structure causes stress marks in large <strong>crystal</strong>s<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Benefits and detriments<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Benefits <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Easy passage <strong>of</strong> electrons<br />

Detriments <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Difficult to grow with Cz technique<br />

Loose structure causes stress marks in large <strong>crystal</strong>s<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Benefits and detriments<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Benefits <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Easy passage <strong>of</strong> electrons<br />

Detriments <strong>of</strong> using <strong>InSb</strong> <strong>crystal</strong><br />

Difficult to grow with Cz technique<br />

Loose structure causes stress marks in large <strong>crystal</strong>s<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

<strong>Czochralski</strong> growth <strong>of</strong> ruby<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


<strong>InSb</strong> <strong>crystal</strong><br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Commercial uses <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Benefits and detriments <strong>of</strong> using <strong>InSb</strong><br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Basic assumptions<br />

1 Crystal is axis-symmetric<br />

2 Heat exchange is constant and uni<strong>for</strong>m<br />

3 Mean <strong>crystal</strong> radius is small compared to its length<br />

4 Thermal stress is elastic<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Basic assumptions<br />

1 Crystal is axis-symmetric<br />

2 Heat exchange is constant and uni<strong>for</strong>m<br />

3 Mean <strong>crystal</strong> radius is small compared to its length<br />

4 Thermal stress is elastic<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Basic assumptions<br />

1 Crystal is axis-symmetric<br />

2 Heat exchange is constant and uni<strong>for</strong>m<br />

3 Mean <strong>crystal</strong> radius is small compared to its length<br />

4 Thermal stress is elastic<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Basic assumptions<br />

1 Crystal is axis-symmetric<br />

2 Heat exchange is constant and uni<strong>for</strong>m<br />

3 Mean <strong>crystal</strong> radius is small compared to its length<br />

4 Thermal stress is elastic<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Basic assumptions<br />

1 Crystal is axis-symmetric<br />

2 Heat exchange is constant and uni<strong>for</strong>m<br />

3 Mean <strong>crystal</strong> radius is small compared to its length<br />

4 Thermal stress is elastic<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Variables to consider<br />

Orientation<br />

Shape<br />

Length<br />

Radius<br />

Growth rate<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Variables to consider<br />

Orientation<br />

Shape<br />

Length<br />

Radius<br />

Growth rate<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Variables to consider<br />

Orientation<br />

Shape<br />

Length<br />

Radius<br />

Growth rate<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Variables to consider<br />

Orientation<br />

Shape<br />

Length<br />

Radius<br />

Growth rate<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Variables to consider<br />

Orientation<br />

Shape<br />

Length<br />

Radius<br />

Growth rate<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Variables to consider<br />

Orientation<br />

Shape<br />

Length<br />

Radius<br />

Growth rate<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Orientation<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Alignment affects stress points in <strong>crystal</strong><br />

[001] ε1<br />

0.03<br />

0.045<br />

0.04<br />

0.035<br />

0.03<br />

[001] ε2<br />

0.18<br />

0.16<br />

0.14<br />

0.12<br />

0<br />

0.025<br />

0.02<br />

0.1<br />

0.08<br />

0.015<br />

0.06<br />

0.01<br />

0.04<br />

0.005<br />

0.02<br />

-0.03<br />

0<br />

0<br />

0.03<br />

[211] ε1<br />

0.045<br />

0.18<br />

0.04<br />

0.16<br />

0.035<br />

0.14<br />

6<br />

4<br />

0<br />

0.03<br />

0.025<br />

0.02<br />

[211] ε 2<br />

0<br />

0.12<br />

0.1<br />

0.08<br />

0.015<br />

0.06<br />

2<br />

0.01<br />

0.04<br />

0.005<br />

0.02<br />

0<br />

-0.03<br />

0<br />

[111] ε 1<br />

0<br />

[111] ε 2<br />

0<br />

-2<br />

0.03<br />

0.045<br />

0.18<br />

0.04<br />

0.16<br />

-4<br />

0.035<br />

0.14<br />

-6<br />

6<br />

4<br />

2<br />

0<br />

-2<br />

-4<br />

-6<br />

-6<br />

-4<br />

-2<br />

0<br />

2<br />

4<br />

6<br />

0<br />

-0.03<br />

0.03<br />

0.025<br />

0.02<br />

0.015<br />

0.01<br />

0.005<br />

0.12<br />

0.1<br />

0.08<br />

0.06<br />

0.04<br />

0.02<br />

“Best” orientation [¯211]<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Orientation<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Alignment affects stress points in <strong>crystal</strong><br />

[001] ε1<br />

0.03<br />

0.045<br />

0.04<br />

0.035<br />

0.03<br />

[001] ε2<br />

0.18<br />

0.16<br />

0.14<br />

0.12<br />

0<br />

0.025<br />

0.02<br />

0.1<br />

0.08<br />

0.015<br />

0.06<br />

0.01<br />

0.04<br />

0.005<br />

0.02<br />

-0.03<br />

0<br />

0<br />

0.03<br />

[211] ε1<br />

0.045<br />

0.18<br />

0.04<br />

0.16<br />

0.035<br />

0.14<br />

6<br />

4<br />

0<br />

0.03<br />

0.025<br />

0.02<br />

[211] ε 2<br />

0<br />

0.12<br />

0.1<br />

0.08<br />

0.015<br />

0.06<br />

2<br />

0.01<br />

0.04<br />

0.005<br />

0.02<br />

0<br />

-0.03<br />

0<br />

[111] ε 1<br />

0<br />

[111] ε 2<br />

0<br />

-2<br />

0.03<br />

0.045<br />

0.18<br />

0.04<br />

0.16<br />

-4<br />

0.035<br />

0.14<br />

-6<br />

6<br />

4<br />

2<br />

0<br />

-2<br />

-4<br />

-6<br />

-6<br />

-4<br />

-2<br />

0<br />

2<br />

4<br />

6<br />

0<br />

-0.03<br />

0.03<br />

0.025<br />

0.02<br />

0.015<br />

0.01<br />

0.005<br />

0.12<br />

0.1<br />

0.08<br />

0.06<br />

0.04<br />

0.02<br />

“Best” orientation [¯211]<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Shape<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Affects stresses on edges <strong>of</strong> <strong>crystal</strong><br />

Shapes compared:<br />

Cylinder<br />

Cone<br />

‘Best’ shape:<br />

Cone<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Shape<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Affects stresses on edges <strong>of</strong> <strong>crystal</strong><br />

Shapes compared:<br />

Cylinder<br />

Cone<br />

‘Best’ shape:<br />

Cone<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Shape<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Affects stresses on edges <strong>of</strong> <strong>crystal</strong><br />

Shapes compared:<br />

Cylinder<br />

Cone<br />

‘Best’ shape:<br />

Cone<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Shape<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Affects stresses on edges <strong>of</strong> <strong>crystal</strong><br />

Shapes compared:<br />

Cylinder<br />

Cone<br />

‘Best’ shape:<br />

Cone<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Shape<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Affects stresses on edges <strong>of</strong> <strong>crystal</strong><br />

Shapes compared:<br />

Cylinder<br />

Cone<br />

‘Best’ shape:<br />

Cone<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Shape<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Affects stresses on edges <strong>of</strong> <strong>crystal</strong><br />

Shapes compared:<br />

Cylinder<br />

Cone<br />

‘Best’ shape:<br />

Cone<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Shape<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Affects stresses on edges <strong>of</strong> <strong>crystal</strong><br />

Shapes compared:<br />

Cylinder<br />

Cone<br />

‘Best’ shape:<br />

Cone<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Cylindrical<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

1<br />

unsteady<br />

pseudo-steady<br />

1<br />

2<br />

unsteady<br />

pseudo-steady<br />

2<br />

1<br />

0.9<br />

ε = ε 1 ε = ε 1 ε = ε 2 ε = ε 2<br />

0.9<br />

1.8<br />

1.8<br />

0.9<br />

0.8<br />

0.8<br />

1.6<br />

1.6<br />

0.8<br />

0.7<br />

0.7<br />

1.4<br />

1.4<br />

0.7<br />

0.6<br />

0.6<br />

1.2<br />

1.2<br />

0.6<br />

z<br />

0.5<br />

z<br />

0.5<br />

z<br />

1<br />

z<br />

1<br />

0.5<br />

0.4<br />

0.4<br />

0.8<br />

0.8<br />

0.4<br />

0.3<br />

0.3<br />

0.6<br />

0.6<br />

0.3<br />

0.2<br />

0.2<br />

0.4<br />

0.4<br />

0.2<br />

0.1<br />

0.1<br />

0.2<br />

0.2<br />

0.1<br />

0<br />

0 1 2<br />

r<br />

0<br />

0 1 2<br />

r<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

0<br />

0 1 2<br />

r<br />

0<br />

0 1 2<br />

r<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth<br />

0


Conical<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

1<br />

unsteady<br />

pseudo-steady<br />

1<br />

2<br />

unsteady<br />

pseudo-steady<br />

2<br />

1<br />

0.9<br />

ε = ε 1 ε = ε 1 ε = ε 2 ε = ε 2<br />

0.9<br />

1.8<br />

1.8<br />

0.9<br />

0.8<br />

0.8<br />

1.6<br />

1.6<br />

0.8<br />

0.7<br />

0.7<br />

1.4<br />

1.4<br />

0.7<br />

0.6<br />

0.6<br />

1.2<br />

1.2<br />

0.6<br />

z<br />

0.5<br />

z<br />

0.5<br />

z<br />

1<br />

z<br />

1<br />

0.5<br />

0.4<br />

0.4<br />

0.8<br />

0.8<br />

0.4<br />

0.3<br />

0.3<br />

0.6<br />

0.6<br />

0.3<br />

0.2<br />

0.2<br />

0.4<br />

0.4<br />

0.2<br />

0.1<br />

0.1<br />

0.2<br />

0.2<br />

0.1<br />

0<br />

0 1 2<br />

r<br />

0<br />

0 1 2<br />

r<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

0<br />

0 1 2<br />

r<br />

0<br />

0 1 2<br />

r<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth<br />

0


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Stress on cylindrical and conical <strong>crystal</strong>s<br />

1<br />

0.9<br />

0.8<br />

1<br />

2<br />

2<br />

ε = ε 1<br />

ε = ε 1 ε = ε 2 ε = ε 2<br />

0.9<br />

0.16 1.8<br />

1.8<br />

0.8<br />

0.14 1.6<br />

1.6<br />

0.7<br />

0.6<br />

0.7<br />

0.7<br />

0.12<br />

1.4<br />

1.4<br />

0.5<br />

0.6<br />

0.6<br />

0.1<br />

1.2<br />

1.2<br />

0.4<br />

z<br />

0.5<br />

0.4<br />

z<br />

0.5<br />

0.4<br />

1<br />

0.08<br />

0.8<br />

z<br />

z<br />

1<br />

0.8<br />

0.3<br />

0.3<br />

0.2<br />

0.3<br />

0.2<br />

0.06<br />

0.04<br />

0.6<br />

0.4<br />

0.6<br />

0.4<br />

0.2<br />

0.1<br />

0.1<br />

0.02<br />

0.2<br />

0.2<br />

0.1<br />

0<br />

0 1 2<br />

r<br />

0<br />

0 1 2<br />

r<br />

0<br />

0<br />

0 1 2<br />

r<br />

0<br />

0 1 2<br />

r<br />

0<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Length and radius<br />

Larger <strong>crystal</strong>s have more stress<br />

Greater temperature change with respect to radius<br />

Larger <strong>crystal</strong>s needed <strong>for</strong> commercial purposes<br />

Fewer boundary effects<br />

Clearer reception<br />

Larger receptors<br />

Current largest clean <strong>crystal</strong> grown commercially: 10 cm<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Length and radius<br />

Larger <strong>crystal</strong>s have more stress<br />

Greater temperature change with respect to radius<br />

Larger <strong>crystal</strong>s needed <strong>for</strong> commercial purposes<br />

Fewer boundary effects<br />

Clearer reception<br />

Larger receptors<br />

Current largest clean <strong>crystal</strong> grown commercially: 10 cm<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Length and radius<br />

Larger <strong>crystal</strong>s have more stress<br />

Greater temperature change with respect to radius<br />

Larger <strong>crystal</strong>s needed <strong>for</strong> commercial purposes<br />

Fewer boundary effects<br />

Clearer reception<br />

Larger receptors<br />

Current largest clean <strong>crystal</strong> grown commercially: 10 cm<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Length and radius<br />

Larger <strong>crystal</strong>s have more stress<br />

Greater temperature change with respect to radius<br />

Larger <strong>crystal</strong>s needed <strong>for</strong> commercial purposes<br />

Fewer boundary effects<br />

Clearer reception<br />

Larger receptors<br />

Current largest clean <strong>crystal</strong> grown commercially: 10 cm<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Length and radius<br />

Larger <strong>crystal</strong>s have more stress<br />

Greater temperature change with respect to radius<br />

Larger <strong>crystal</strong>s needed <strong>for</strong> commercial purposes<br />

Fewer boundary effects<br />

Clearer reception<br />

Larger receptors<br />

Current largest clean <strong>crystal</strong> grown commercially: 10 cm<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Length and radius<br />

Larger <strong>crystal</strong>s have more stress<br />

Greater temperature change with respect to radius<br />

Larger <strong>crystal</strong>s needed <strong>for</strong> commercial purposes<br />

Fewer boundary effects<br />

Clearer reception<br />

Larger receptors<br />

Current largest clean <strong>crystal</strong> grown commercially: 10 cm<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Length and radius<br />

Larger <strong>crystal</strong>s have more stress<br />

Greater temperature change with respect to radius<br />

Larger <strong>crystal</strong>s needed <strong>for</strong> commercial purposes<br />

Fewer boundary effects<br />

Clearer reception<br />

Larger receptors<br />

Current largest clean <strong>crystal</strong> grown commercially: 10 cm<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Length and radius<br />

Larger <strong>crystal</strong>s have more stress<br />

Greater temperature change with respect to radius<br />

Larger <strong>crystal</strong>s needed <strong>for</strong> commercial purposes<br />

Fewer boundary effects<br />

Clearer reception<br />

Larger receptors<br />

Current largest clean <strong>crystal</strong> grown commercially: 10 cm<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Growth rate<br />

Slower growth rate creates cleaner <strong>crystal</strong>s<br />

Impractical<br />

Necessary to grow faster <strong>for</strong> commercial purposes<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Growth rate<br />

Slower growth rate creates cleaner <strong>crystal</strong>s<br />

Impractical<br />

Necessary to grow faster <strong>for</strong> commercial purposes<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Growth rate<br />

Slower growth rate creates cleaner <strong>crystal</strong>s<br />

Impractical<br />

Necessary to grow faster <strong>for</strong> commercial purposes<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Growth rate<br />

Slower growth rate creates cleaner <strong>crystal</strong>s<br />

Impractical<br />

Necessary to grow faster <strong>for</strong> commercial purposes<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Strain equations<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Strain is relative displacement<br />

Example: If a L = 1m long bar stretches ∆L = 1cm <strong>the</strong>n <strong>the</strong><br />

strain is ∆L/L = 0.01.<br />

Derived from displacement vector u : R 3 ↦→ R 3<br />

Dependent on <strong>the</strong> <strong>the</strong>rmal perturbations<br />

One possible representation<br />

⎛<br />

⎞<br />

e rr e rφ e rz<br />

e = ⎝e φr e φφ e φz<br />

⎠ , e T = e.<br />

e zr e zφ e zz<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Strain equations<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Strain is relative displacement<br />

Example: If a L = 1m long bar stretches ∆L = 1cm <strong>the</strong>n <strong>the</strong><br />

strain is ∆L/L = 0.01.<br />

Derived from displacement vector u : R 3 ↦→ R 3<br />

Dependent on <strong>the</strong> <strong>the</strong>rmal perturbations<br />

One possible representation<br />

⎛<br />

⎞<br />

e rr e rφ e rz<br />

e = ⎝e φr e φφ e φz<br />

⎠ , e T = e.<br />

e zr e zφ e zz<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Strain equations<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Strain is relative displacement<br />

Example: If a L = 1m long bar stretches ∆L = 1cm <strong>the</strong>n <strong>the</strong><br />

strain is ∆L/L = 0.01.<br />

Derived from displacement vector u : R 3 ↦→ R 3<br />

Dependent on <strong>the</strong> <strong>the</strong>rmal perturbations<br />

One possible representation<br />

⎛<br />

⎞<br />

e rr e rφ e rz<br />

e = ⎝e φr e φφ e φz<br />

⎠ , e T = e.<br />

e zr e zφ e zz<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Strain equations<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Strain is relative displacement<br />

Example: If a L = 1m long bar stretches ∆L = 1cm <strong>the</strong>n <strong>the</strong><br />

strain is ∆L/L = 0.01.<br />

Derived from displacement vector u : R 3 ↦→ R 3<br />

Dependent on <strong>the</strong> <strong>the</strong>rmal perturbations<br />

One possible representation<br />

⎛<br />

⎞<br />

e rr e rφ e rz<br />

e = ⎝e φr e φφ e φz<br />

⎠ , e T = e.<br />

e zr e zφ e zz<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Strain equations<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Strain is relative displacement<br />

Example: If a L = 1m long bar stretches ∆L = 1cm <strong>the</strong>n <strong>the</strong><br />

strain is ∆L/L = 0.01.<br />

Derived from displacement vector u : R 3 ↦→ R 3<br />

Dependent on <strong>the</strong> <strong>the</strong>rmal perturbations<br />

One possible representation<br />

⎛<br />

⎞<br />

e rr e rφ e rz<br />

e = ⎝e φr e φφ e φz<br />

⎠ , e T = e.<br />

e zr e zφ e zz<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Strain equations<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Strain is relative displacement<br />

Example: If a L = 1m long bar stretches ∆L = 1cm <strong>the</strong>n <strong>the</strong><br />

strain is ∆L/L = 0.01.<br />

Derived from displacement vector u : R 3 ↦→ R 3<br />

Dependent on <strong>the</strong> <strong>the</strong>rmal perturbations<br />

One possible representation<br />

⎛<br />

⎞<br />

e rr e rφ e rz<br />

e = ⎝e φr e φφ e φz<br />

⎠ , e T = e.<br />

e zr e zφ e zz<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

In our case, with displacement vector u = 〈u(r), 0, 0〉 in<br />

cylindrical coordinates,<br />

e rr = ∂u<br />

∂r → u r ,<br />

e zz = ∂w<br />

∂z → 0,<br />

2e rz = ∂u<br />

∂z + ∂w<br />

∂r<br />

→ 0,<br />

e φφ = 1 ∂v<br />

r ∂φ + u r → u r ,<br />

2e φz = 1 ∂w<br />

r ∂φ + ∂v<br />

∂z → 0,<br />

2e rφ = ∂v<br />

∂r − v r + 1 ∂u<br />

r ∂φ → 0.<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Stress equations<br />

Pressures (stress) that give rise to relative displacements<br />

(strain)<br />

Dependent on strain equations<br />

General matrix equation (isotropic material)<br />

σ ij =<br />

where<br />

E<br />

(1 + ν) e Eν<br />

ij +<br />

(1 + ν)(1 − 2ν) e llδ ij − α 0(T − T g )E<br />

δ ij ,<br />

(1 − 2ν)<br />

or, in our case,<br />

e ll = e rr + e φφ + e zz , δ ij =<br />

e ll = u r + u r<br />

{<br />

1 i = j<br />

0 i ≠ j<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Stress equations<br />

Pressures (stress) that give rise to relative displacements<br />

(strain)<br />

Dependent on strain equations<br />

General matrix equation (isotropic material)<br />

σ ij =<br />

where<br />

E<br />

(1 + ν) e Eν<br />

ij +<br />

(1 + ν)(1 − 2ν) e llδ ij − α 0(T − T g )E<br />

δ ij ,<br />

(1 − 2ν)<br />

or, in our case,<br />

e ll = e rr + e φφ + e zz , δ ij =<br />

e ll = u r + u r<br />

{<br />

1 i = j<br />

0 i ≠ j<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Stress equations<br />

Pressures (stress) that give rise to relative displacements<br />

(strain)<br />

Dependent on strain equations<br />

General matrix equation (isotropic material)<br />

σ ij =<br />

where<br />

E<br />

(1 + ν) e Eν<br />

ij +<br />

(1 + ν)(1 − 2ν) e llδ ij − α 0(T − T g )E<br />

δ ij ,<br />

(1 − 2ν)<br />

or, in our case,<br />

e ll = e rr + e φφ + e zz , δ ij =<br />

e ll = u r + u r<br />

{<br />

1 i = j<br />

0 i ≠ j<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Stress equations<br />

Pressures (stress) that give rise to relative displacements<br />

(strain)<br />

Dependent on strain equations<br />

General matrix equation (isotropic material)<br />

σ ij =<br />

where<br />

E<br />

(1 + ν) e Eν<br />

ij +<br />

(1 + ν)(1 − 2ν) e llδ ij − α 0(T − T g )E<br />

δ ij ,<br />

(1 − 2ν)<br />

or, in our case,<br />

e ll = e rr + e φφ + e zz , δ ij =<br />

e ll = u r + u r<br />

{<br />

1 i = j<br />

0 i ≠ j<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Stress equations<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Stress-strain (constitutive) relationship depends on material<br />

More convenient representation <strong>for</strong> isotropic material<br />

where<br />

σ = Ce − α 0 (T − T g )(C 11 + 2C 12 )I,<br />

⎛<br />

⎞<br />

C 11 C 12 C 12 0 0 0<br />

C 12 C 11 C 12 0 0 0<br />

C =<br />

C 12 C 12 C 11 0 0 0<br />

⎜ 0 0 0 C 44 0 0<br />

,<br />

⎟<br />

⎝ 0 0 0 0 C 44 0 ⎠<br />

0 0 0 0 0 C 44<br />

e T = (e rr , e φφ , e zz , 2e φz , 2e rz , 2e rφ ),<br />

σ T = (σ rr , σ φφ , σ zz , σ φz , σ rz , σ rφ ).<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Stress equations<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Stress-strain (constitutive) relationship depends on material<br />

More convenient representation <strong>for</strong> isotropic material<br />

where<br />

σ = Ce − α 0 (T − T g )(C 11 + 2C 12 )I,<br />

⎛<br />

⎞<br />

C 11 C 12 C 12 0 0 0<br />

C 12 C 11 C 12 0 0 0<br />

C =<br />

C 12 C 12 C 11 0 0 0<br />

⎜ 0 0 0 C 44 0 0<br />

,<br />

⎟<br />

⎝ 0 0 0 0 C 44 0 ⎠<br />

0 0 0 0 0 C 44<br />

e T = (e rr , e φφ , e zz , 2e φz , 2e rz , 2e rφ ),<br />

σ T = (σ rr , σ φφ , σ zz , σ φz , σ rz , σ rφ ).<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Stress equations<br />

Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

In our case (isotropic: 2C 44 − C 11 + C 12 )<br />

which gives us<br />

σ ij =<br />

as be<strong>for</strong>e.<br />

C 11 =<br />

C 12 =<br />

C 44 =<br />

(1 − ν)E<br />

(1 + ν)(1 − 2ν) ,<br />

νE<br />

(1 + ν)(1 − 2ν) ,<br />

E<br />

2(1 + ν) ,<br />

E<br />

(1 + ν) e Eν<br />

ij +<br />

(1 + ν)(1 − 2ν) e llδ ij − α 0(T − T g )E<br />

δ ij<br />

(1 − 2ν)<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

von Mises stress<br />

Used to find <strong>the</strong> maximal stress<br />

von Mises stress equation<br />

For us<br />

σ VM = (σ φφ − σ zz ) 2 + (σ rr − σ zz ) 2 + (σ rr − σ φφ ) 2<br />

2σ VM = 1 4 ε2 Θ 12<br />

1 r 4 + 1 16 ε2 Θ 12<br />

1 (3r 2 − R 2 ) 2 + 1<br />

16 ε2 Θ 12<br />

1 (r 2 − R 2 ) 2<br />

or<br />

σ VM = 1 4 ε ∣ ∣Θ 1 (<br />

∣ r<br />

) 2 ( r<br />

) ) 4<br />

1 R<br />

(1 2 − 4 + 7 .<br />

R R<br />

with Θ 1 1 ≃ ∂T /∂r<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

von Mises stress<br />

Used to find <strong>the</strong> maximal stress<br />

von Mises stress equation<br />

For us<br />

σ VM = (σ φφ − σ zz ) 2 + (σ rr − σ zz ) 2 + (σ rr − σ φφ ) 2<br />

2σ VM = 1 4 ε2 Θ 12<br />

1 r 4 + 1 16 ε2 Θ 12<br />

1 (3r 2 − R 2 ) 2 + 1<br />

16 ε2 Θ 12<br />

1 (r 2 − R 2 ) 2<br />

or<br />

σ VM = 1 4 ε ∣ ∣Θ 1 (<br />

∣ r<br />

) 2 ( r<br />

) ) 4<br />

1 R<br />

(1 2 − 4 + 7 .<br />

R R<br />

with Θ 1 1 ≃ ∂T /∂r<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

von Mises stress<br />

Used to find <strong>the</strong> maximal stress<br />

von Mises stress equation<br />

For us<br />

σ VM = (σ φφ − σ zz ) 2 + (σ rr − σ zz ) 2 + (σ rr − σ φφ ) 2<br />

2σ VM = 1 4 ε2 Θ 12<br />

1 r 4 + 1 16 ε2 Θ 12<br />

1 (3r 2 − R 2 ) 2 + 1<br />

16 ε2 Θ 12<br />

1 (r 2 − R 2 ) 2<br />

or<br />

σ VM = 1 4 ε ∣ ∣Θ 1 (<br />

∣ r<br />

) 2 ( r<br />

) ) 4<br />

1 R<br />

(1 2 − 4 + 7 .<br />

R R<br />

with Θ 1 1 ≃ ∂T /∂r<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

von Mises stress<br />

Used to find <strong>the</strong> maximal stress<br />

von Mises stress equation<br />

For us<br />

σ VM = (σ φφ − σ zz ) 2 + (σ rr − σ zz ) 2 + (σ rr − σ φφ ) 2<br />

2σ VM = 1 4 ε2 Θ 12<br />

1 r 4 + 1 16 ε2 Θ 12<br />

1 (3r 2 − R 2 ) 2 + 1<br />

16 ε2 Θ 12<br />

1 (r 2 − R 2 ) 2<br />

or<br />

σ VM = 1 4 ε ∣ ∣Θ 1 (<br />

∣ r<br />

) 2 ( r<br />

) ) 4<br />

1 R<br />

(1 2 − 4 + 7 .<br />

R R<br />

with Θ 1 1 ≃ ∂T /∂r<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Fur<strong>the</strong>r studies include<br />

Minimizing maximum von Mises stress<br />

Dynamically investigating optimal shape<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Fur<strong>the</strong>r studies include<br />

Minimizing maximum von Mises stress<br />

Dynamically investigating optimal shape<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

The model<br />

Future work<br />

Fur<strong>the</strong>r studies include<br />

Minimizing maximum von Mises stress<br />

Dynamically investigating optimal shape<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

In conclusion<br />

To sum up<br />

We have<br />

found quick <strong>method</strong> <strong>of</strong> predicting stress <strong>for</strong> any given pr<strong>of</strong>ile<br />

removed axis symmetry condition (facets)<br />

removed isotropy condition (splitting C = C 0 − C a )<br />

We are working on<br />

minimizing von Mises stress<br />

finding optimal growth rate and shape up to second order<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

In conclusion<br />

To sum up<br />

We have<br />

found quick <strong>method</strong> <strong>of</strong> predicting stress <strong>for</strong> any given pr<strong>of</strong>ile<br />

removed axis symmetry condition (facets)<br />

removed isotropy condition (splitting C = C 0 − C a )<br />

We are working on<br />

minimizing von Mises stress<br />

finding optimal growth rate and shape up to second order<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

In conclusion<br />

To sum up<br />

We have<br />

found quick <strong>method</strong> <strong>of</strong> predicting stress <strong>for</strong> any given pr<strong>of</strong>ile<br />

removed axis symmetry condition (facets)<br />

removed isotropy condition (splitting C = C 0 − C a )<br />

We are working on<br />

minimizing von Mises stress<br />

finding optimal growth rate and shape up to second order<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

In conclusion<br />

To sum up<br />

We have<br />

found quick <strong>method</strong> <strong>of</strong> predicting stress <strong>for</strong> any given pr<strong>of</strong>ile<br />

removed axis symmetry condition (facets)<br />

removed isotropy condition (splitting C = C 0 − C a )<br />

We are working on<br />

minimizing von Mises stress<br />

finding optimal growth rate and shape up to second order<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

In conclusion<br />

To sum up<br />

We have<br />

found quick <strong>method</strong> <strong>of</strong> predicting stress <strong>for</strong> any given pr<strong>of</strong>ile<br />

removed axis symmetry condition (facets)<br />

removed isotropy condition (splitting C = C 0 − C a )<br />

We are working on<br />

minimizing von Mises stress<br />

finding optimal growth rate and shape up to second order<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

In conclusion<br />

To sum up<br />

We have<br />

found quick <strong>method</strong> <strong>of</strong> predicting stress <strong>for</strong> any given pr<strong>of</strong>ile<br />

removed axis symmetry condition (facets)<br />

removed isotropy condition (splitting C = C 0 − C a )<br />

We are working on<br />

minimizing von Mises stress<br />

finding optimal growth rate and shape up to second order<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

In conclusion<br />

To sum up<br />

We have<br />

found quick <strong>method</strong> <strong>of</strong> predicting stress <strong>for</strong> any given pr<strong>of</strong>ile<br />

removed axis symmetry condition (facets)<br />

removed isotropy condition (splitting C = C 0 − C a )<br />

We are working on<br />

minimizing von Mises stress<br />

finding optimal growth rate and shape up to second order<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

In conclusion<br />

To sum up<br />

We have<br />

found quick <strong>method</strong> <strong>of</strong> predicting stress <strong>for</strong> any given pr<strong>of</strong>ile<br />

removed axis symmetry condition (facets)<br />

removed isotropy condition (splitting C = C 0 − C a )<br />

We are working on<br />

minimizing von Mises stress<br />

finding optimal growth rate and shape up to second order<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

In conclusion<br />

To sum up<br />

We have<br />

found quick <strong>method</strong> <strong>of</strong> predicting stress <strong>for</strong> any given pr<strong>of</strong>ile<br />

removed axis symmetry condition (facets)<br />

removed isotropy condition (splitting C = C 0 − C a )<br />

We are working on<br />

minimizing von Mises stress<br />

finding optimal growth rate and shape up to second order<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Bohun, C.S. Stress analysis <strong>of</strong> Cz grown <strong>InSb</strong>, not published.<br />

Bohun, C.S., Frigaard, I., Huang, H., and Liang, S. (2006) A<br />

semianalytical <strong>the</strong>rmal stress model <strong>for</strong> <strong>the</strong> <strong>Czochralski</strong> growth<br />

<strong>of</strong> type III-V compounds, SIAM J Appl. Math, vol. 66, no. 5,<br />

pp. 1533-1562.<br />

Huang, H. and Liang, S. (2007) Thermal-stress reduction <strong>for</strong> a<br />

<strong>Czochralski</strong> grown single <strong>crystal</strong>, Springer J Eng Math, vol. 59,<br />

pp. 1-23.<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth


Background<br />

Analysis <strong>of</strong> <strong>InSb</strong> <strong>crystal</strong><br />

Summary<br />

References<br />

Thank you<br />

Devon Armstrong, Faculty <strong>of</strong> Science<br />

<strong>Optimization</strong> <strong>of</strong> <strong>the</strong> <strong>Czochralski</strong> <strong>method</strong> <strong>for</strong> <strong>InSb</strong> <strong>crystal</strong> growth

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