A large variety of applications require structured resist architectures which achieve long-term stability against organic solvents after a subsequent hardening step. Novolac-based resists show a considerable stabilisation against organic solvents like e.g. toluene, acetone, IPA, PMA, or NEP for several hours after a bake at temperatures > 150 °C. In the case of CAR-resists, the stabilisation is in addition supported by an intense flood exposure.
It could now be demonstrated explicitly for AR-P 7400.23 as example that a sufficiently high stabilisation against toluene is already possible by intense flood exposure and subsequent hard bake at 110 °C, while a hard bake at 150 °C in addition to flood exposure is required for a stabilisation against ethanol. The stabilisation is in this case so strong that structures are even in ethanol stable for several hours.
Overview General Process