Mathematical simulation of soft baking in photoresist processing

The soft-baking procedure in photoresist processing is investigated theoret ically. A Landau transformation coupled with a finite-difference scheme is adopted to solving the moving-boundary problem under consideration. The exp erimental data of Shipley SPR5110LA. m-p cresol novolak, poly(methyl methac rylate), Shipley UVIII, and Shipley SNR200 photoresists reported in the lit erature are analyzed to justify the applicability of the model derived. We show that the concentration dependence of the diffusivecular ty of solvent can have a significant influence on the soft-baking procedure. The rate of transfer of solvent is controlled by the molecular diffusion of solvent in a film. (C) 2000 The Electrochemical Society. S0013-4651 (99)07-030-5. All rights reserved.