Temperature　fast　change　during　a　step　or　several　steps　is　required　by　latest　etching　process　in　IC　manufacturing.　Two　methods　to　reach　this　requirement　was　described,　and　several　simulation　devices　are　designed　to　test　the　capability.　The　temperature　control　unit　(TCU)　need　to　provide　two　different　channels　coolant　with　high　and　low　temperature.　One　method　is　to　switch　the　different　channels　connect　to　main　tool　electrostatic　chuck　(ESC).　Two　different　base　temperatures　can　be　used　for　main　tool,　the　heater　in　the　ESC　is　controlled　to　get　the　final　temperature.　Another　is　to　mix　the　two　different　temperatures　with　motor　valves　to　reach　the　target　temperature.　Two　types　of　equipment　are　developed　using　the　corresponding　method.　The　test　devices　are　introduced,　and　the　test　shows　transient　temperature　response　of　two　equipment.　Both　channels　must　return　to　their　respective　set　points　with　±1°C　variation　within　120　seconds.　The　maximum　deviation　of　supply　temperature　must　below　20　when　temperature　ramp　up　or　ramp　down.　These　TCU　can　support　the　latest　etching　process　and　the　switch　or　mix　test　with　simulation　devices　can　be　used　to　judge　the　TCU　performance.　©　2021　IEEE.