Method and apparatus for adaptive process control of critical dimensions during spin coating process

摘要

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: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; andA, B, C and D are constant coefficients.