METHOD AND APPARATUS FOR RECOVERING AND REUSING RESIST COMPOSITION

摘要

A resist composition scattered from a spinner during the application into a silicon wafer in a coating chamber (1) is collected into one of preparatory recovery tanks (2,2') and then sent to a recovery tank (3) having a temperature sensor (8), a level sensor (9) and a viscosity sensor (4). The recovery tank (3) is kept (6) at a constant temperature, whereas the viscosity of the resist composition is adjusted to a predetermined value by automatically supplying a necessary amount of solvent (5) via an electro-magnetic valve (5'). The resist composition is then stored in storage tanks (7) kept at a constant temperature and reused in the coatings chamber whenever necessary, after filtering (11) undesirable substances.