Mentor Graphics was acquired by Siemens in 2017. EDA is now part of Siemens Digital Industries. This year, they published a paper for SPIE EUV virtual conference, "Gaussian Random Field EUV stochastic models, their generalizations and lithographically meaningful stochastic metrics." https://www.spiedigitallibrary.org/...and-lithographically/10.1117/12.2583792.short
I had used fairly simple models without significant computational resources to explore stochastic effects (not always limited to EUV) in some articles, some of which were also posted here at SemiWiki. So I was quite glad to see the same issues covered in more detail with the full use of EDA resources.
The paper particularly had a focus on the deprotection modeling. Chemically amplified resists work by having acids generated from photon absorption; these acids then go on to catalyze more acid generation, and also deprotect the resist, or render it dissolvable in developer afterwards. The reactive species generating the acids are depleted by continued exposure; this is the new consideration added.
The paper goes on to investigate stochastics effects in a variety of cases: bridging of sparse (132 nm pitch) lines (10-18 nm CD); via/contact area variation leading to conductance variation (I had covered this here: https://semiwiki.com/lithography/300871-stochastic-origins-of-euv-feature-edge-roughness/ as well as here:
), tip-to-tip, SRAF printability, and pinch points.
The expected dose effect is dramatically shown as well:
If interested in a copy, please let me know.
I had used fairly simple models without significant computational resources to explore stochastic effects (not always limited to EUV) in some articles, some of which were also posted here at SemiWiki. So I was quite glad to see the same issues covered in more detail with the full use of EDA resources.
The paper particularly had a focus on the deprotection modeling. Chemically amplified resists work by having acids generated from photon absorption; these acids then go on to catalyze more acid generation, and also deprotect the resist, or render it dissolvable in developer afterwards. The reactive species generating the acids are depleted by continued exposure; this is the new consideration added.
The paper goes on to investigate stochastics effects in a variety of cases: bridging of sparse (132 nm pitch) lines (10-18 nm CD); via/contact area variation leading to conductance variation (I had covered this here: https://semiwiki.com/lithography/300871-stochastic-origins-of-euv-feature-edge-roughness/ as well as here:
The expected dose effect is dramatically shown as well:
If interested in a copy, please let me know.
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