Patent ID: 8241994

Claim:
A method for fabricating an isolation layer in a semiconductor device, comprising: forming a trench in a semiconductor substrate; forming a flowable insulation layer on the trench and the semiconductor substrate; placing the semiconductor substrate formed with the flowable insulation layer in a curing apparatus; optionally implementing a first curing step comprising heating at a low temperature of 300° C. to 400° C. while supplying an oxidant source on the flowable insulation layer to control shrinkage of the flowable insulation layer; implementing a second curing step comprising continuously raising the temperature in the curing apparatus to an increased temperature in the range of 650° C. to 700° C.; optionally implementing a third curing step comprising maintaining the temperature in the curing apparatus at a temperature in the range of 650° C. to 750° C. for a predetermined time to stabilize the flowable insulation layer; implementing a fourth curing step comprising continuously raising the temperature in the curing apparatus to a temperature in the range of 830° C. to 1100° C. to induce compressive stress; and implementing a fifth curing step comprising maintaining the temperature in the curing apparatus at a high temperature in the range of 830° C. to 1100° C. for 50 minutes to 70 minutes to convert the flowable insulation layer to a silicon oxide layer; and forming an isolation layer by planarizing the silicon oxide layer.