6 September 1978 The Interferometric Analysis Of Flatness By Eye And Computer
Author Affiliations +
The semiconductor industry is presently striving to increase the information density as well as the die size of most new integrated circuits. This goal, coupled with the simul-taneous shift towards projection and proximity printing, has dramatically increased the need for more precise manufacturing and quality control techniques. Both projection and proximity printers suffer from a very limited depth of focus. This focal length "budget" varies from printer to printer, depending upon the basic system design, as well as any residual image or alignment errors. The ability of these optical systems to reproduce high spatial frequency information is intimately tied to the flatness of the photomask reticle and silicon wafer upon which the information is to be printed. Specifically, this paper will deal with the quantitative analysis of surface flatness and how it relates to the flatness measurement of masks and wafers. Classical as well as contemporary surface testing interferometers will be described in order to exemplify and explain the observed fringe patterns. Fringe analysis methods will be described, including an example of the most advanced computerized techniques. This paper concludes that surface testing interferometry will become the "work horse" of flatness measurement in the semiconductor-micro-lithography industry, just as it has in the optical industry.
© (1978) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Charles Edward Synborski, Charles Edward Synborski, } "The Interferometric Analysis Of Flatness By Eye And Computer", Proc. SPIE 0135, Developments in Semiconductor Microlithography III, (6 September 1978); doi: 10.1117/12.956119; https://doi.org/10.1117/12.956119

Back to Top