SUBSTRATE TREATING METHOD

摘要

A substrate treating method comprising the step of oxidizing the surface of a silicon substrate to form an oxide film, the step of nitriding the oxide film to form an oxynitrided film, and the step of removing oxygen from a nidriding-effected environment after the above oxidizing step and before the above nitriding step. Accordingly, an increase in an oxide film caused by oxygen remaining in the atmosphere is restricted, and a very thin oxynitrided film suitable for the gate insulation film of a ultra-high-speed semiconductor device can be formed.