SEMICONDUCTOR DEVICE AND METHOD FOR FORMING ISOLATION PART THEREIN

摘要

PROBLEM TO BE SOLVED: To reduce parasitic leak of a shallow trench isolation via. SOLUTION: A distance between a silicon nitride liner 43 and an active silicon sidewall is increased by depositing an insulation oxide layer 20 prior to depositing of the silicon nitride liner 43. Preferably, the insulation oxide layer 20 comprises tetraethyl orthosilicate. The method includes formation of one or a plurality of shallow trench isolations inside a semiconductor wafer through etching, sticking of an insulation oxide layer 20 inside a trench, formation of thermal oxide 25 inside a trench and sticking of the silicon nitride liner 43 inside a trench. The thermal oxide 25 can be formed before or after the insulation oxide layer 20 is deposited.