Production of a hafnium silicate dielectric layer for use as a gate oxide by solid-state reaction

Abstract

The formation of hafnium silicate films (HfSixOy) for use as gate oxides with large dielectric constant by solid state reaction of Hf metal and SiO2 was investigated. Thin, fully reacted silicate films could be formed, and were thermally stable in vacuum to temperatures in excess of 800 C. The interface between a hafnium silicate layer and the silicon substrate was shown to be stable against SiO2 formation. The results suggest a new processing route for production of a gate insulator having low equivalent oxide thickness.