Zero-Misalignment lithographic process using a photoresist with wavelength-selected tone

Abstract

A novel photoresist capable of dual-tone imaging, and a self-aligning two-level lithographic process which demonstrates its unique properties are described. This resist, composed of a positive and a negative photosensitizer in a phenolic matrix resin, can be imaged in either tone depending on the wavelength of exposure. In the self-aligned process, two distinct latent images, one in positive and one in negative tone, are generated simultaneously during a single exposure using a special mask. The latent images can be developed separately and independently. The alignment between these patterns is defined by the mask and is identical from wafer to wafer. The two patterns can be transferred to the substrate sequentially and with zero alignment error. © 1988, SPIE.