Measurement of low molecular weight silicon AMC to protect UV optics in photo-lithography environments

Jürgen M. Lobert; Charles M. Miller; Anatoly Grayfer; Anne M. Tivin

doi:10.1117/12.816277

23 March 2009 Measurement of low molecular weight silicon AMC to protect UV optics in photo-lithography environments

Jürgen M. Lobert, Charles M. Miller, Anatoly Grayfer, Anne M. Tivin

Proceedings Volume 7272, Metrology, Inspection, and Process Control for Microlithography XXIII; 727222 (2009) https://doi.org/10.1117/12.816277
Event: SPIE Advanced Lithography, 2009, San Jose, California, United States

Abstract

A new analytical method for semiconductor-specific applications is presented for the accurate measurement of low molecular weight, silicon-containing, organic compounds TMS, HMDSO and D3. Low molecular weight / low boiling point silicon-containing compounds are not captured for extended periods of time by traditional chemical filters but have the same potential to degrade exposure tool optical surfaces as their high molecular weight counterparts. Likewise, we show that capturing these compounds on sample traps that are commonly used for organic AMC analysis does not work for various reasons. Using the analytical method described here, TMS, HMDSO and D3 can be measured artifact-free, with at least a 50:1 peak-to-noise ratio at the method detection limit, determined through the Hubaux-Vos method and satisfying a conservative 99% statistical confidence. Method detection limits for the compounds are 1-6 ppt in air. We present calibration curve, capacity, capture efficiency, break-through and repeatability data to demonstrate robustness of method. Seventy-one real-world samples from 26 projects taken in several fab environments show that TMS is found in concentrations 100 times higher than those of HMDSO and D3. All compounds are found in all environments in concentrations ranging from zero to 12 ppm, but most concentrations were below 50 ppb. All compounds are noticeably higher in litho-bays than in sub-fabs and we found all three compounds inside of two exposure tools, suggesting cleanroom and/or tool-internal contamination sources.

Citation Download Citation

Jürgen M. Lobert, Charles M. Miller, Anatoly Grayfer, and Anne M. Tivin "Measurement of low molecular weight silicon AMC to protect UV optics in photo-lithography environments", Proc. SPIE 7272, Metrology, Inspection, and Process Control for Microlithography XXIII, 727222 (23 March 2009); https://doi.org/10.1117/12.816277

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available