Patent ID: 7696047

Claim:
A method for forming a gate insulation film for use in a semiconductor device, the semiconductor device including a semiconductor substrate having a source region, a drain region, a channel region provided between the source region and the drain region and an element separate structure surrounding the source region, the drain region and the channel region, the gate insulation film being provided so as to cover the semiconductor substrate, and a gate electrode provided so as to face the channel region via the gate insulation film, and wherein the gate insulation film is formed of an insulative inorganic material as a main material, the insulative inorganic material containing silicon and oxygen, the gate insulating film further containing hydrogen atoms, the method comprising: preparing the semiconductor substrate; forming the element separate structure so as to compartmentalize one surface of the semiconductor substrate into a plurality of regions; forming the gate insulation film so as to cover the semiconductor substrate and the element separate structure; subjecting the gate insulation film to which an electric field has never been applied to Fourier Transform Infrared Spectroscopy at room temperature after formation of the gate insulation film on the semiconductor substrate and the element separate structure; and evaluating the gate insulation film characteristic based on measurement results of the gate insulation film by the Fourier Transform Infrared Spectroscopy, the characteristic being evaluated as to whether the following conditions (1) and (2) are satisfied; (1) at least a part of the absorbance of infrared radiation has a wave number in the range of 830 to 900 cm −1 , and (2) in the case where an absolute value of a difference between absorbance of infrared radiation at a wave number of 830 cm −1 and the absorbance of infrared radiation at a wave number of 770 cm −1 is defined as A and an absolute value of a difference between absorbance of infrared radiation at a wave number of 900 cm −1 and absorbance of infrared radiation at a wave number of 990 cm −1 is defined as B, then A and B satisfy a following relation: A/B is 1.8 or more.