Semiconductor device having field plate electrode and method for manufacturing the same
First Claim
1. A method for manufacturing a semiconductor device, comprising:
- forming a second semiconductor layer of a first conductivity type on a first semiconductor layer of the first conductivity type;
forming a trench in the second semiconductor layer;
forming a first conductive film in the trench through a first insulating film so as to bury the trench;
removing the first insulating film of the upper portion of the trench on an opening side of the trench;
oxidizing the side surface of the upper portion of the exposed trench and the entire upper portion of the exposed first conductive film so as to form a gate insulating film and a second insulating film;
forming a gate electrode between the gate insulating film and the second insulating film;
forming a third semiconductor layer of the second conductivity type in the upper portion of the second semiconductor layer; and
forming a fourth semiconductor layer of the first conductivity type in the upper portion of the third semiconductor layer.
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Accused Products
Abstract
According to one embodiment, in a semiconductor device, a first semiconductor layer of a first conductivity type has a first impurity concentration. A second semiconductor layer of the first conductivity type is formed on the first semiconductor layer and has a second impurity concentration lower than the first impurity concentration. A field plate electrode is formed in a lower portion of a trench formed in the second semiconductor layer through a first insulating film so as to bury the lower portion of the trench. A second insulating film is formed in the upper portion of the trench so as to be in contact with the top surface of the field plate electrode. A gate electrode is formed in the upper portion of the trench through a gate insulating film so as to bury the upper portion of the trench to sandwich the second insulating film.
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Citations
7 Claims
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1. A method for manufacturing a semiconductor device, comprising:
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forming a second semiconductor layer of a first conductivity type on a first semiconductor layer of the first conductivity type; forming a trench in the second semiconductor layer; forming a first conductive film in the trench through a first insulating film so as to bury the trench; removing the first insulating film of the upper portion of the trench on an opening side of the trench; oxidizing the side surface of the upper portion of the exposed trench and the entire upper portion of the exposed first conductive film so as to form a gate insulating film and a second insulating film; forming a gate electrode between the gate insulating film and the second insulating film; forming a third semiconductor layer of the second conductivity type in the upper portion of the second semiconductor layer; and forming a fourth semiconductor layer of the first conductivity type in the upper portion of the third semiconductor layer. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification