Variable thickness self-aligned photoresist process

摘要

A process for forming with a single masking step regions of different thicknesses in a photo-sensitive layer is disclosed. A masking member or reticle includes opaque and transparent areas and areas with a grating. The pitch of the periodic grating is of a lesser dimension than can be resolved by the masking projection apparatus. The photo-sensitive region illuminated by the grating receives uniform illumination at an intermediate intensity, thereby providing, after developing, a layer with regions of intermediate thickness.