Evaluation of Dislocation Generation at Si3 N 4 Film Edges on Silicon Substrates by Selective Oxidation

Abstract

The density of dislocations generated at film edges on silicon substrate by selective oxidation is measured and the relation between the selective oxidation conditions and dislocation generation at the film edges is investigated. Dislocations are observed using Secco etching. The results show that the density of dislocations does not continuously increase with oxidation temperature, but decreases markedly at temperatures above 1000°C. A further experiment with recessed oxide structure reveals that the generation of dislocations depends strongly on the cross‐sectional structure of the sample These results are interpreted in terms of viscous flow of film. Another experiment suggests that high pressure oxidation is not effective for suppressing dislocation generation, although it is useful for reducing oxidation time. Finally, collector‐emitter shorts of transistors in bipolar integrated circuits are examined quantitatively using a simple statistical method in relation to the dislocations generated at film edges.