SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SAME
First Claim
1. A semiconductor device comprising:
- a first semiconductor layer having a first conductivity type;
a second semiconductor layer having the first conductivity type and provided on the first semiconductor layer, a concentration of impurity of the first conductivity type included in the second semiconductor layer being lower than a concentration of impurity of the first conductivity type included in the first semiconductor layer;
a third semiconductor layer having a second conductivity type and provided on the second semiconductor layer, the third semiconductor layer having a first portion and a second portion surrounding the first portion in a plane perpendicular to stacking direction of the first semiconductor layer and the second semiconductor layer, a concentration of impurity of the first conductivity type included in the third semiconductor layer being lower than the concentration of impurity of the first conductivity type included in the second semiconductor layer;
a fourth semiconductor layer having the first conductivity type and provided on the first portion;
a gate electrode extending from the fourth semiconductor layer toward the second semiconductor layer and having a lower end located in the second semiconductor layer;
a field plate electrode provided below the gate electrode and having a lower end located in the second semiconductor layer;
an insulating film provided between the gate electrode and the fourth semiconductor layer, between the gate electrode and the first portion, between the gate electrode and the second semiconductor layer, between the gate electrode and the field plate electrode, and between the field plate electrode and the second semiconductor layer;
a first main electrode electrically connected to the first semiconductor layer;
a second main electrode electrically connected to the third semiconductor layer and the fourth semiconductor layer; and
an insulating section provided at least between the first portion and the second portion and electrically insulating between the first portion and the second portion.
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Accused Products
Abstract
A semiconductor device includes first to fourth semiconductor layers, a gate electrode, a field plate electrode, an insulating film, first and second main electrodes, and an insulating section. The second semiconductor layer has the first conductivity type and is provided on the first semiconductor layer. The third semiconductor layer has a second conductivity type and is provided on the second semiconductor layer. A concentration of impurity of the first conductivity type included in the third semiconductor layer is lower than the concentration of impurity of the first conductivity type included in the second semiconductor layer. The fourth semiconductor layer is provided on the third semiconductor layer. The gate electrode extends from the fourth semiconductor layer toward the second semiconductor layer. The field plate electrode is provided below the gate electrode.
42 Citations
20 Claims
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1. A semiconductor device comprising:
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a first semiconductor layer having a first conductivity type; a second semiconductor layer having the first conductivity type and provided on the first semiconductor layer, a concentration of impurity of the first conductivity type included in the second semiconductor layer being lower than a concentration of impurity of the first conductivity type included in the first semiconductor layer; a third semiconductor layer having a second conductivity type and provided on the second semiconductor layer, the third semiconductor layer having a first portion and a second portion surrounding the first portion in a plane perpendicular to stacking direction of the first semiconductor layer and the second semiconductor layer, a concentration of impurity of the first conductivity type included in the third semiconductor layer being lower than the concentration of impurity of the first conductivity type included in the second semiconductor layer; a fourth semiconductor layer having the first conductivity type and provided on the first portion; a gate electrode extending from the fourth semiconductor layer toward the second semiconductor layer and having a lower end located in the second semiconductor layer; a field plate electrode provided below the gate electrode and having a lower end located in the second semiconductor layer; an insulating film provided between the gate electrode and the fourth semiconductor layer, between the gate electrode and the first portion, between the gate electrode and the second semiconductor layer, between the gate electrode and the field plate electrode, and between the field plate electrode and the second semiconductor layer; a first main electrode electrically connected to the first semiconductor layer; a second main electrode electrically connected to the third semiconductor layer and the fourth semiconductor layer; and an insulating section provided at least between the first portion and the second portion and electrically insulating between the first portion and the second portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method for manufacturing a semiconductor device, comprising:
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forming a workpiece by forming a second semiconductor film on a major surface of a first semiconductor substrate having a first conductivity type, the second semiconductor film having a lower impurity concentration than the first semiconductor substrate, and by forming a third semiconductor film having a second conductivity type on the second semiconductor film by epitaxial growth, the workpiece including the first semiconductor substrate, the second semiconductor film, and the third semiconductor film and having a device region and a termination region surrounding the device region in a plane parallel to the major surface; forming a gate trench penetrating through the third semiconductor film to part of the second semiconductor film in the device region, and a termination trench penetrating through the third semiconductor film to part of the second semiconductor film at a boundary between the device region and the termination region; forming a first insulating layer on an inner wall surface of the gate trench and the termination trench; forming a field plate electrode in a portion of the gate trench below the third semiconductor film by embedding a conductive material in a remaining space in the gate trench; removing a portion of the first insulating layer above the field plate electrode; forming a second insulating layer above the field plate electrode in the gate trench and on the inner wall surface of the gate trench above the field plate electrode, and forming a gate electrode by embedding a conductive material in a remaining space in the gate trench; and selectively doping an upper portion of the device region of the third semiconductor film with impurity of the first conductivity type. - View Dependent Claims (19, 20)
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Specification