摘要 |
After forming a first gate electrode and a second gate electrode on a semiconductor substrate, a silicon oxide film is formed to cover an n-channel MISFET forming region, and a p-channel MISFET forming region is exposed. Subsequently, after a first element supply film made of, for example, an aluminum oxide film is formed on the whole surface of the semiconductor substrate, a heat treatment is performed. By this means, a high-concentration HfAlO film and a low-concentration HfAlO film are formed by diffusing aluminum into the first insulating film just below the second gate electrode. Thereafter, by using a magnesium oxide film as a second element supply film, magnesium is diffused into the first insulating film just below the first gate electrode, thereby forming a high-concentration HfMgO film and a low-concentration HfMgO film.
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