Abstract: It is an object of the present invention to provide a semiconductor device capable of decreasing electric resistance of a lower electrode provided therein, as well as capable of accurately responding to external signals having high frequencies inputted therein. The lower electrode 7 consists of three layers such as a silicon lower electrode layer 7a made of poly-crystalline silicon, a tungsten-silicide layer 7b made of tungsten silicide as a chemical compound of tungsten and silicon, and a protection layer 7c made of poly-crystalline silicon. By constructing the semiconductor device as described above, oxidation of the tungsten-silicide layer 7b may be prevented by the protection layer 7c made of poly-crystalline silicon even when oxidation layers of an ONO (silicon oxidation) layer 11 is formed by thermal oxidation. Consequently, electric resistance of the lower electrode 7 can be decreased.

Abstract: It is an object of the present invention to provide a semiconductor device capable of decreasing electric resistance of a lower electrode provided therein, as well as capable of accurately responding to external signals having high frequencies inputted therein. The lower electrode 7 consists of three layers such as a silicon lower electrode layer 7a made of poly-crystalline silicon, a tungsten-silicide layer 7b made of tungsten silicide as a chemical compound of tungsten and silicon, and a protection layer 7c made of poly-crystalline silicon. By constructing the semiconductor device as described above, oxidation of the tungsten-silicide layer 7b may be prevented by the protection layer 7c made of poly-crystalline silicon even when oxidation layers of an ONO (silicon oxidation) layer 11 is formed by thermal oxidation. Consequently, electric resistance of the lower electrode 7 can be decreased.

Abstract: It is an object of the present invention to provide a semiconductor device capable of decreasing electric resistance of a lower electrode provided therein, as well as capable of accurately responding to external signals having high frequencies inputted therein. The lower electrode 7 consists of three layers such as a silicon lower electrode layer 7a made of poly-crystalline silicon, a tungsten-silicide layer 7b made of tungsten silicide as a chemical compound of tungsten and silicon, and a protection layer 7c made of poly-crystalline silicon. By constructing the semiconductor device as described above, oxidation of the tungsten-silicide layer 7b may be prevented by the protection layer 7c made of poly-crystalline silicon even when oxidation layers of an ONO (silicon oxidation) layer 11 is formed by thermal oxidation. Consequently, electric resistance of the lower electrode 7 can be decreased.

Abstract: It is an object of the present invention to provide a semiconductor device capable of decreasing electric resistance of a lower electrode provided therein, as well as capable of accurately responding to external signals having high frequencies inputted therein. The lower electrode 7 consists of three layers such as a silicon lower electrode layer 7a made of poly-crystalline silicon, a tungsten-silicide layer 7b made of tungsten silicide as a chemical compound of tungsten and silicon, and a protection layer 7c made of poly-crystalline silicon. By constructing the semiconductor device as described above, oxidation of the tungsten- silicide layer 7b may be prevented by the protection layer 7c made of poly-crystalline silicon even when oxidation layers of an ONO (silicon oxidation) layer 11 is formed by thermal oxidation. Consequently, electric resistance of the lower electrode 7 can be decreased.