Patent ID: 6638827
Filing Date: 2003-10-28
Classification: H01L

Abstract:
A method of manufacturing a semiconductor device, comprising:providing a resist layer partially over a semiconductor layer of a first conductive type; applying impurities of the second conductive type to the semiconductor layer while using the resist layer as a mask; removing the resist layer; diffusing the impurities to form a drift region in the semiconductor layer; disposing oxidation-resistant films over the drift region and on the semiconductor layer outside the drift region; forming a resist film partially on the semiconductor layer including over the oxidation-resistant films, said resist films leaving gaps to the drift region; implanting impurities of the second conductive type in the drift region using the oxidation-resistant film and the resist film as a mask to form an ion-implanted layer in the drift region; removing the resist film; forming a selective oxide film by locally oxidizing the semiconductor layer using the oxidation-resistant film as a mask; diffusing the ion-implanted layer to form an impurity layer of the second conduction type in the drift region; forming a gate oxide film by thermally oxidizing the semiconductor layer using the selective oxide film as a mask; forming a gate electrode that extends from the gate oxide film to the selective oxide film; forming a source region of the second conductive type at one side of the gate electrode by implanting impurities of the second conductive type using the gate electrode and the selective oxide film as a mask; and forming a drain region of the second conductive type in the drift region at another side of the gate electrode.