Semiconductor device and method for manufacturing semiconductor device
A semiconductor device comprising a semiconductor substrate, a gate dielectrics formed on the semiconductor substrate and including a silicon oxide film containing a metallic element, the silicon oxide film containing the metallic element including a first region near a lower surface thereof, a second region near an upper surface thereof, and a third region between the first and second regions, the metallic element contained in the silicon oxide film having a density distribution in a thickness direction of the silicon oxide film, a peak of the density distribution existing in the third region, and an electrode formed on the gate dielectrics.
1. A method of manufacturing a semiconductor device, including forming a silicon oxide film containing a metallic element on a semiconductor substrate by a CVD method, comprising:
starting supply of an organic compound containing silicon into a chamber in which a semiconductor substrate is held;
starting supply of an organic compound containing a metallic element into the chamber, while continuously supplying the organic compound containing silicon into the chamber; and
increasing a supply amount of the organic compound containing the metallic element.
2. The method according to claim 1 , further comprising:
decreasing a supply amount of the organic compound containing the metallic element, after the increasing a supply amount of the organic compound containing the metallic element;
stopping the supply of the organic compound containing the metallic element; and
stopping the supply of the organic compound containing silicon, after stopping the supply of the organic compound containing the metallic element.
3. The method according to claim 2 , further comprising nitriding a surface of a silicon oxide film containing the metallic element and obtained after stopping the supply of the organic compound containing silicon.
4. The method according to claim 1 , wherein the organic compound containing silicon is an alkoxide compound of silicon.
5. The method according to claim 4 , wherein the alkoxide compound of silicon is tetraethoxysilane.
6. The method according to claim 1 , wherein the organic compound containing the metallic element is an alkoxide compound of the metallic element.
7. The method according to claim 6 , wherein the alkoxide compound of the metallic element is a tertiarybuthoxy compound.