Method of manufacturing semiconductor device
AssigneeSanyo Electric Co., Ltd.
InventorTakashi Ogura
Life of this patent
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Abstract
In a semiconductor device manufacturing method of the present invention, a polysilicon film and a silicon nitride film are deposited on an upper surface of an epitaxial layer. Patterning is performed so that the polysilicon film and the silicon nitride film are left in regions in which a LOCOS oxide film is to be formed. Then, using steps of the polysilicon film and the silicon nitride film as alignment marks, a diffusion layer as drain regions is formed. Subsequently, the LOCOS oxide film is formed. This manufacturing method enables the diffusion layer to be formed with high position accuracy without being affected by a shape of the LOCOS oxide film.
Claims5
A method of manufacturing a semiconductor device, comprising the steps of:
- forming an insulating layer on a surface of a semiconductor layer, and selectively removing the insulating layer so that an opening portion is provided over the semiconductor layer in a region in which a field oxide film is to be formed;
- depositing resist over the surface of the semiconductor layer, then selectively removing the resist using steps of the insulating layer as alignment marks, and forming a drain diffusion layer using the resist as a mask;
- forming the field oxide film from the surface of the semiconductor layer using the insulating layer, removing part of the insulating layer, and then forming gate electrodes so that at least one ends of the gate electrodes are placed over the field oxide film;
- and
- forming a back-gate diffusion layer so that part of the back-gate diffusion layer is placed under other ends of the gate electrodes, and forming a source diffusion layer from a surface of the back-gate diffusion layer.
Dependencies are inferred from the claim text.