Study of aging effects in a chemical amplification resist: SAL601-ER7

The shelf life and film life of the electron beam resist, Microposit SAL601‐ER7 from Shipley, were studied. Solutions and films of this resist were found to exhibit a performance degradation which is a function of the storage time and temperature. Refrigeration significantly improves the stability of the resist. Component studies were used to determine that the shelf life problem is due to an interaction between the novolak resin and melamine crosslinker. Results indicate that considerable stability can be realized by using less reactive crosslinkers in the resist formulation.