Method for forming thermal oxide film on semiconductor substrate and method for producing semiconductor device

Abstract

The present invention provides a method for forming a thermal oxide film, comprising the steps of: a step of acquiring a first correlation between an amount of OH groups and thickness of the thermal oxide film by forming a thermal oxide film by thermal oxidation treatment under the same condition after preparing a plurality of semiconductor substrates having chemical oxide films formed by cleaning and having different amounts of OH groups; a step of acquiring a second correlation between an amount of OH groups and drying conditions by cleaning under the same cleaning condition followed by changed drying conditions to substrates and measuring amounts of OH groups; a step of acquiring a third correlation between drying condition and thickness of thermal oxide film by using the first correlation and the second correlation; a step of determining drying condition and thermal oxidation condition by using the third correlation; a step of cleaning the substrates; and a step of drying and a thermal oxide film formation after the cleaning step using the drying conditions and thermal oxidation treatment conditions determined in the drying and thermal oxidation treatment condition determination step. This provides a method for forming thermal oxide film in which a thermal oxide film can be formed with intended thickness with good reproducibility while without changing the composition of the cleaning chemical solution.