Patent ID: 7915179

Claim:
An insulating film forming method, comprising: nitriding an oxide film on an object substrate through a plasma nitriding treatment; and annealing the nitrided object substrate, wherein said annealing includes sequential steps of: heating up the nitrided object substrate at a first heat-up rate to a first fixed temperature between 600° C. and 700° C.; performing a first annealing treatment on the nitrided object substrate while maintaining the nitrided object substrate at the first fixed temperature for an annealing time of about 1 to 40 seconds; heating up the nitrided object substrate at a second heat-up rate from the first fixed temperature to a second temperature of 950° C. to 1150° C.; and performing a second annealing treatment on the nitrided object substrate while maintaining the nitrided object substrate at the second temperature for an annealing time of about 5 to 60 seconds, and wherein the sequential steps of said annealing are performed while maintaining the nitrided object substrate at a pressure of 66.7 Pa to 933.2 Pa in an oxidizing atmosphere.