Patent ID: 6489205
Filing Date: 2002-12-03
Classification: H01L

Abstract:
A method for manufacturing a semiconductor device including a plurality of isolation oxide films of different thickness, the method comprising steps of:forming a nitride film on a silicon substrate; forming openings in the nitride film; and forming isolation oxide films below the openings through thermal oxidation, and wherein the openings include an opening having a diameter equal to or more than 0.6 &mgr;m as well as an opening having a diameter less than 0.6 &mgr;m; the thermal oxidation is carried out under a condition by which the isolation oxide film formed under the opening having the diameter equal to or more than 0.6 &mgr;m grows to a desired thickness; and the diameter less than 0.6 &mgr;m is set such that an isolation oxide film formed under the opening having the diameter less than 0.6 &mgr;m grows to a desired thickness in a case where the thermal oxidation is carried out under said condition.