Design specific variation in pattern transfer by via/contact etch ...
Design specific variation in pattern transfer by via/contact etch ...
Design specific variation in pattern transfer by via/contact etch ...
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Calibration/Prediction – Resist Model<br />
� CM1(Compact Model 1) is a Mentor Graphics resist model.<br />
It provides a dense simulation <strong>by</strong> consider<strong>in</strong>g acid and base neutralization, diffusion length dur<strong>in</strong>g the<br />
exposure, bak<strong>in</strong>g, and resist development phases.<br />
� The output of the model is a resist contour<br />
obta<strong>in</strong>ed from the exposure threshold T :<br />
� Each term M i(I) is of the form:<br />
Simulated, nm<br />
285<br />
275<br />
265<br />
255<br />
245<br />
235<br />
225<br />
215<br />
205<br />
+/-b is the neutralization operator (+ for acid, - for base concentration),<br />
y = 0.80x + 43.77<br />
R2 R = 0.805<br />
2 = 0.805<br />
195<br />
195 205 215 225 235 245 255 265 275 285<br />
Measured, nm<br />
M<br />
( ) ) n<br />
∑ci<br />
Mi<br />
I =<br />
k n<br />
1/<br />
∇ I b ⊗Gs<br />
, p<br />
= ±<br />
CD, nm<br />
300<br />
280<br />
260<br />
240<br />
220<br />
200<br />
180<br />
( ) T<br />
Measured<br />
Simulated<br />
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39<br />
Via No.<br />
� Optical diameter = 2.56um<br />
� NA = 0.659<br />
� Model is calibrated on BARC open<strong>in</strong>g<br />
CD.<br />
� Result : R2 = 0.81<br />
Copyright ©2008, Mentor Graphics.
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