Damage formation and annealing studies of low energy ion implants ...

implantation conditions are those used for device manufacturing, i.e. a 3 keV As +
implant to a fluence of 2E15 cm -2 . These implants have been carried out into crystalline
Si (No PAI), and Si pre-amorphised with a 130 keV Xe + implant to a fluence of 2E14
cm -2 (PAI). This results in a Si amorphisation depth of 100 nm as measured with XTEM
(13). The results obtained for two annealing conditions are presented here, these are
furnace annealing at 600 °C for 20 minutes and spike annealing to 1130 °C. The sample
after high temperature spike anneal is representative of current manufacturing methods.
The results following the low temperature furnace anneal are included primarily for
comparison with SR results.
6.2.3.1 MEIS results
The MEIS analysis conditions used were a nominally 100 keV He + beam with the
samples aligned along the [īīı] channelling direction relative to the beam. The analyser
was positioned to record data along the [111] and [332] blocking directions. MEIS
energy spectra from along the [111] blocking direction, for both PAI and NoPAI sample
series, are shown in Figure 6.3. Also included in the figure for reference is a spectrum
from a virgin Si sample and a random spectrum taken from an amorphous Si sample.
Yield (counts per 5 µC)
450
400
350
300
250
200
150
100
50
0
O depth (nm)
6 4 2 0
3keV As 2E15 ion/cm 2 [111] Blocking direction
Si depth (nm)
16 14 12 10 8 6 4 2 0
70 72 74 76 78 80 82 84 86 88 90 92 94 96
Energy (keV)
124
virgin
Random
3 keV as-impl
3 keV 600C 20mins
3 keV 1130C spike
3 keV as-impl PAI
3 keV 600C 20mins PAI
3 keV 1130C spike PAI
As depth (nm)
16 14 12 10 8 6 4 2 0
Figure 6.3 MEIS spectra collected along the [111] blocking direction. The non-implanted
Si sample and a random amorphous Si spectrum are shown for comparison.