Method of manufacturing a semiconductor device having regions of different conductivity types isolated by field oxide
AssigneeNippon Steel Corporation
InventorsAtsushi Kawasaki, Kohei Eguchi, Katsuki Hazama, Fumitaka Sugaya
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Abstract
A semiconductor device has, in one embodiment, two wells of different conductivity types formed in a semiconductor substrate. The two wells are arranged to be adjacent to each other to form a junction therebetween. A field oxide film is formed to cover the junction at a main surface of the semiconductor substrate. Other field oxide films or field-shield isolation structures may be formed to isolate circuit elements from one another in the wells.
Claims3
A method of manufacturing a semiconductor device having an isolation structure using a field oxide film and an isolation structure using a shield gate electrode, comprising the steps of:
- forming in serial order a first insulating film, a poly-silicon film, and an oxidation prevention film on a main surface of a semiconductor substrate;
- removing said oxidation prevention film over the portion of said substrate at which said field oxide film, constituting said isolation structure, is to be formed;
- selectively oxidizing said substrate by using said remaining oxidation prevention film as a mask to form from said field oxide film an isolation structure;
- subsequently processing said poly-silicon film into the pattern of said shield gate electrode forming an isolation structure;
- and
- forming a second insulating film on the side surface of said poly-silicon film having the pattern of said shield gate electrode.
Dependencies are inferred from the claim text.