Patent ID: 6914013

Claim:
A method of fabricating a semiconductor device having a composite dielectric layer comprised of a first oxide layer, a nitride layer and second oxide layer, comprising: providing a semiconductor substrate; depositing the first oxide layer on the semiconductor substrate by a LPCVD process at a temperature of from about 650 to about 800° C., and at a pressure of from about 1 to about 100 Pa; subjecting the substrate to first annealing under an atmosphere selected from the group consisting of N 2 O, NO and NH 3 to form a surface layer in the first oxide layer containing less than 5% nitrogen; depositing the nitride layer on the first oxide layer; depositing the second oxide layer on the nitride layer by a LPCVD process at a temperature of from about 650 to about 800° C., and at a pressure of from about 1 to about 100 Pa; and subjecting the substrate to a second annealing under an atmosphere selected from the group consisting of N 2 O, NO and NH 3 to form a surface layer in the second oxide layer containing less than 5% nitrogen.