DEVELOPER TEMPERATURE EFFECT ON NEGATIVE DEEP-ULTRAVIOLET RESISTS - CHARACTERIZATION, MODELING, AND SIMULATION

We consider the effect of developer (solvent) temperature in the disso lution of both the exposed and unexposed parts of the resist. The spin -formatted resist film tends to have macromolecules oriented parallel to the substrate surface. The orientation of the resist macromolecules introduces an anisotropic component to the etch rate: higher in the d irection parallel to the substrate surface and lower in the perpendicu lar one. We performed a series of experiments on resist-coated Si wafe rs using a stepper and a deep ultraviolet source at 248 nm using SNR-2 48 negative resist. We obtained scanning electron micrographs for vari ous developer temperatures. The variation of the lateral etch rate man ifested itself in sidewall profile slopes and is compatible with the e ntropy directional flow. Simulation using the Cellular Automata model predicted identical results. (C) 1997 American Vacuum Society.