Direct pattern transfer using an inorganic polymer-derived silicate etch mask

Abstract

Advancements in patterning materials combined with facile fabrication techniques have been critical for the development of the semiconductor industry. In order to develop a new silicate etch mask for direct pattern transfer onto silicon via etching, methacrylated polyvinylsilazane, an inorganic polymer photoresist acting as a patternable silicate precursor, was used to fabricate micron-scale patterns over a large area upon 6 inch silicon wafers by conventional photolithography. The photolithographic patterns obtained were hydrolyzed to convert the polymer phase into the silicate phase after post-heat treatment at 150 °C. The silicate patterns were transferred as an etch mask onto silicon wafers via dry plasma etching process using various ratios of an SF₆/Cl₂/Ar mixture as etchant. The silicate patterns revealed an excellent etching selectivity of 16 for silicon, which was 8–16 times higher than the polymer phase.