Real-Time, In-Situ Measurement of Film Thickness and Uniformity During Plasma Ashing of Photoresist
Copyright © 1990 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. This paper is also available at http://dx.doi.org/10.1117/12.48948.
NOTE: At the time of publication, the author Richard Savage was not yet affiliated with Cal Poly.
This paper will discuss the performance of equipment which monitors and so controls photoresist thickness and uniformity during plasma ashing without interfering with the process. Practical monitoring of a subtractive process of this type is significantly more complex than monitoring deposition processes. An initial absolute thickness measurement is needed. In addition the device must view the layer through a luminous medium and cannot rely on simple optical interference fringe counting. The equipment is self-calibrating and sensitive to layers dnm thick. An application to partial plasma resist ashing in high uniformity equipment will be described. Application to other films (e. g. oxide) will be discussed
Richard N. Savage, Horace Simmons, John T. Davies, and Thomas Metz. "Real-Time, In-Situ Measurement of Film Thickness and Uniformity During Plasma Ashing of Photoresist" Advanced Techniques for Integrated Circuit Processing 1392 (1990): 551-554.
Available at: http://works.bepress.com/rsavage/24