Title

Method and Apparatus for Adaptive Process Control of Critical Dimensions During Spin Coating Process

Author Info

Richard N. Savage, Silicon Valley Group, Inc., San Jose, CAFollow
Emir Gurer, Silicon Valley Group, Inc., San Jose, CA

Recommended Citation

United States Patent Number: 6,177,133, January 23, 2001.

NOTE: At the time of publication, the author Richard Savage was not yet affiliated with Cal Poly.

Abstract

A spin coating process for controlling the mean thickness of photoresist on the surface of a semiconductor wafer. The wafer surface has a central axis normal to the surface. The process comprises the steps of applying the solution to the wafer surface and spinning the wafer about the central axis at a spindle speed until the solution has dried. The spindle speed is a function of the desired mean thickness of the photoresist, the barometric pressure and the relative humidity. The spindle speed is determined from a statistical model described by the equation: MT=A+BxRH+CxBP+D/SS^1/2 wherein: MT is mean thickness in Å; RH is relative humidity in percent; BP is barometric pressure in mm of Hg; SS is spindle speed in rpm; and A, B, C and D are constant coefficients.

Disciplines

Materials Science and Engineering

Number of Pages

8

Publisher statement

Also available from the United States Patent and Trademark Office. Website: http://www.uspto.gov.