Oxynitride gate dielectric, especially for a semiconductor memory device, produced by silicon substrate reaction or CVD to form an oxynitride layer and back-oxidation to form an intermediate silicon dioxide layer

摘要

Oxynitride gate dielectric formation comprises oxynitride layer formation on a silicon substrate by reaction or CVD and back-oxidation to form an intermediate silicon dioxide layer. Oxynitride gate dielectric formation in a semiconductor device comprises: (a) contacting the upper surface of a silicon substrate with a nitrogen- and/or oxygen-containing gas at = 500 deg C to form an oxynitride layer; and (b) contacting the substrate and the layer with an oxygen- and halogen compound-containing gas to form a silicon dioxide layer between the oxynitride layer and the substrate. Independent claims are also included for the following: (i) a similar process in which the oxynitride layer is formed by CVD; (ii) a gate dielectric in a semiconductor device, comprising a SiO2 spacer layer between a silicon substrate and an oxynitride layer; and (iii) a gate stack in a semiconductor device, comprising a silicon substrate bearing a sequence of a SiO2 spacer layer, an oxynitride layer, a SiO2 layer and a conductive gate.