Control of spatial and transient temperature trajectories for photoresist processing

wSpatial and transient control of temperature trajectories by a new thermal cycling module is presented, with a focus on photoresist processing applic ations for semiconductor wafers and quartz reticles. In the proposed unit, the bake and chill steps are conducted sequentially within the same module without any substrate movement. The unit includes two heating sources. The first is a circulating fluid which can be switched between hot and cold res ervoirs and serves as the dominant means for heat transfer. The second is a set of thermoelectric devices which are used to provide a distributed amou nt of heat to the substrate for uniformity and transient temperature contro l. Experimental data is provided to demonstrate temperature uniformity duri ng both transient and steady state operation. The flexibility of the system to develop new processing temperature trajectories is presented. (C) 1999 American Vacuum Society.