New photoresist coating method for high topography surfaces

A novel technique of photoresist coating, Dynamic Surface Tension (DST) coating, is presented. This technique is particularly well suited for surfaces with pre-existing topography, which is often the case in micro-electro-mechanical systems (MEMS) and integrated circuits packaging. A simple setup is employed and several resist solutions are tested. Promising results are obtained using a commercial photoresist Shipley SPR 220-3.0. Uniform coverage on micromachined surfaces with high topography is demonstrated. Successful pattern transfer at the bottom and on top of silicon trenches as deep as 15 ¿m with different width from 1 ¿m to 100 ¿m was achieved with 1.5 ¿m resolution.