Selective Oxidation Using Ultrathin Nitrogen‐Rich Silicon Surface Layers Grown by Rapid Thermal Processing

Abstract

A method for selective oxidation using ultrathin nitrogen-rich layers (<20A) grown by rapid thermal processing is presented. Oxidation inhibition in these layers is shown to be a function of the previous oxide layer thickness and the N2-SI reaction conditions during the rapid thermal nitridation cycle. The oxide growth inhibition property of these layers is tested for rapid thermal and furnace grown oxides. Since oxide growth inhibition appears to be a strong function of the initial oxide thickness, the rapid thermal nitridation process is more controllable than conventional furnace methods because of the shorter exposure time to oxygen contamination. Characterization of the nitridation reaction, the influence of the initial oxide thickness, and the localized inhibition phenomenon are presented with the aim of making this technique useful for novel VLSI structures.

Ultrathin SiOxNy by rapid thermal heating of silicon in N2 at T=760–1050 °C

“…For example, experiments done in an RTP system clearly show the inhibition of subsequent oxide growth, due to prenitridation of the substrate at Tу1150°C. 20 A similar effect was observed for furnace prenitrided wafers at temperatures as low as ϳ985°C. 21 In the present letter, we show the formation of SiO x N y films at temperatures as low as 760°C, and measure for the first time, with high accuracy, incorporated nitrogen and oxygen contents.…”