Paper Title
Implementation of Multi-Channel Temperature Controller for Photo Process

Abstract
In semiconductor and display processes, photo lithography is a process of transferring a designed design from a mask or reticle to a photosensitizer on a wafer surface. Among them, the temperature and time of hard bake require precise control because they affect the etch rate of the photosensitizer and the adhesive strength of the photoresist during baking. Excessive burning can cause serious decomposition. If the baking temperature is too low, the thermal polymerization reaction is insufficient, so that the photosensitizer does not harden as much as necessary, and the photosensitizer filling the pinholes is reduced. The Super 2-degree of Freedom PID (Proportional Integral Derivative) algorithm and variable sampling (50~250ms) control presented in this paper were proposed and implemented as a product. Compared with the existing products, the multi-temperature controller using the proposed algorithm shows a big difference in hunting and maintaining stability. When using this product in an automatic control system, as proven by experiments, there is no problem in the process based on excellent performance, and we are confident that it will be widely used based on price competitiveness, scalability and intuitive GUI. Keywords - Hard Bake, Super 2-degree of Freedom PID, Photolithography, Variable Sampling Control, Temperature Controller