摘要 |
After a channel layer (7) containing nitrogen is formed in a channel region (5) in the main surface of a semiconductor substrate (1), a gate insulating film (9) and insulating films (10) are formed as oxide film by a thermal oxidation on the main surface of the semiconductor substrate (1). The insulating films (10) are thicker than the gate insulating film (9) because the oxidation reaction is suppressed in the nitrogen-introduced region. Further, stresses caused by the oxidation are suppressed-around the connections between the gate insulating film (9) and the insulating films (10). Accordingly, reduction in leakage current and improvement of gate insulating film reliability are compatibly realized.
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