Effects of relative humidity variation on photoresist processing

摘要

Abstract: The environmental specifications for submicron photolithographic processes on photocluster tools have traditionally demanded strict setpoint control with very little variation in temperature and humidity. In an effort to reduce support costs, the need for such tight tolerances on relative humidity is being examined. This paper discusses the effects of relative- humidity variation on photoresist thickness after spin-coating and on the final printed-image linewidth after full processing through the photocluster. Two different photoresists are compared using spray- and puddle-develop processing. When the resist thickness is varied by changing the humidity setpoint, the swing-curve correlation between printed-image linewidth and resist thickness is equivalent to one typically generated by changing the photoresist thickness with different casting speeds. !5