Magnetically enhanced reactive ion etching of silicon in bromine plasmas

Publisher Website
Google Scholar
Abstract
Reactive ion etching of single‐crystal and polycrystallinesilicon in bromine has been studied at 2‐mTorr pressure in a magnetically enhanced reactor. Effective voltage thresholds for silicon and thermal SiO2etching are observed at −50‐ and −175‐V cathode bias, respectively. The selectivity of silicon with respect to SiO2 exhibits a sharp peak between these thresholds, attaining, at −100 V, a value of 225 for p‐type and lightly dopedn‐type material. The corresponding etch rate is 65 nm/min. The etch rate doubles for n +‐polysilicon and the peak selectivity is 450. Etching is anisotropic over the entire doping range. Application of the −100‐V process to high‐resolution trench and polysilicon gate fabrication is discussed.

This publication has 0 references indexed in Scilit: