SEMICONDUCTOR DEVICE AND THE METHOD OF MANUFACTURING THE SAME
First Claim
1. A semiconductor device comprising;
- a first semiconductor region of a first conductivity type;
a second semiconductor region of a second conductivity type disposed on the first semiconductor region;
a third semiconductor region of the first conductivity type disposed selectively on the second semiconductor region;
a trench extending through the third and second semiconductor regions and into the first semiconductor region;
a first electrode disposed in the trench with a first insulator film interposed between a side wall of the trench and the first electrode, the first electrode being disposed in a bottom portion of the trench;
a control electrode disposed in the trench with a second insulator film interposed between the side wall of the trench and the control electrode, the control electrode being disposed above the first electrode;
a second electrode in contact with the third semiconductor region; and
a further semiconductor region of the first conductivity type doped more heavily than the first semiconductor region, the further semiconductor region being disposed in a portion of the first semiconductor region and being positioned adjacent the second semiconductor region and the trench,wherein the first electrode is positioned on a first semiconductor region side of a boundary between the first semiconductor region and the second semiconductor region,wherein the first electrode is connected electrically to the second electrode, andwherein the first insulator film is thicker than the second insulator film.
1 Assignment
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Accused Products
Abstract
A semiconductor device includes a p-type well region 3 and an n+ source region 4, both formed selectively in the surface portion of n− drift region 2. A trench 6 is in contact with n+ source region 4 and extends through p-type well region 3 into n− drift region 2. A field plate 8 is formed in trench 6, with a first insulator film 7 being interposed between the trench 6 surface and field plate 8. A gate electrode 10 is formed in trench 6 above field plate 10, with a second insulator film 9 being interposed between the trench 6 surface and gate electrode 10. An n−− lightly doped region 21 in n− drift region 2 crosses under the bottom of trench 6.
0 Citations
12 Claims
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1. A semiconductor device comprising;
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a first semiconductor region of a first conductivity type; a second semiconductor region of a second conductivity type disposed on the first semiconductor region; a third semiconductor region of the first conductivity type disposed selectively on the second semiconductor region; a trench extending through the third and second semiconductor regions and into the first semiconductor region; a first electrode disposed in the trench with a first insulator film interposed between a side wall of the trench and the first electrode, the first electrode being disposed in a bottom portion of the trench; a control electrode disposed in the trench with a second insulator film interposed between the side wall of the trench and the control electrode, the control electrode being disposed above the first electrode; a second electrode in contact with the third semiconductor region; and a further semiconductor region of the first conductivity type doped more heavily than the first semiconductor region, the further semiconductor region being disposed in a portion of the first semiconductor region and being positioned adjacent the second semiconductor region and the trench, wherein the first electrode is positioned on a first semiconductor region side of a boundary between the first semiconductor region and the second semiconductor region, wherein the first electrode is connected electrically to the second electrode, and wherein the first insulator film is thicker than the second insulator film. - View Dependent Claims (2, 3)
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4. A method of manufacturing a semiconductor device, the method comprising the steps of;
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(a) forming a trench in a first semiconductor region of a first conductivity type such that an angle between a bottom surface of the trench and a corner portion of the trench is obtuse; (b) introducing an impurity of a second conductivity type selectively into a surface portion of the first semiconductor region for setting a concentration of an impurity of the first conductivity type in the surface portion of the first semiconductor region exposed to the corner portion of the trench to be low; (c) forming a first electrode in the trench with a first insulator film interposed between a side wall of the trench and the first electrode, step (c) being conducted after the step (b); (d) forming a control electrode in the trench with a second insulator film interposed between the side wall of the trench and the control electrode, the control electrode being formed above the first electrode; and (e) diffusing the impurity of the second conductivity type introduced into the surface portion of the first semiconductor region for forming a further semiconductor region of the first conductivity type, the further semiconductor region being doped more lightly than the first semiconductor region, the further semiconductor region covering the corner portion of the trench. - View Dependent Claims (5, 6, 11, 12)
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7. A method of manufacturing a semiconductor device, the method comprising the steps of:
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(a) forming a trench in a first semiconductor region of a first conductivity type; (b) introducing an impurity of a second conductivity type selectively into a surface portion of the first semiconductor region for setting a concentration of an impurity of the first conductivity type in the surface portion of the first semiconductor region exposed to a bottom surface of the trench to be low; (c) forming a first electrode in the trench with a first insulator film interposed between a side wall of the trench and the first electrode, step (c) being conducted after the step (b); (d) forming a control electrode in the trench with a second insulator film interposed between the side wall of the trench and the control electrode, the control electrode being formed above the first electrode; and (e) diffusing the impurity of the second conductivity type introduced into the surface portion of the first semiconductor region for forming a further semiconductor region of the first conductivity type, the further semiconductor region being doped more lightly than the first semiconductor region, the further semiconductor region crossing under the bottom surface of the trench from a corner portion of the trench, the further semiconductor region covering the bottom surface of the trench. - View Dependent Claims (8)
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9. A method of manufacturing a semiconductor device, the method comprising the steps of:
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(a) forming a trench in a first semiconductor region of a first conductivity type; (b) introducing an impurity of the first conductivity type selectively into a surface portion of the first semiconductor region for setting a concentration of the impurity of the first conductivity type in the surface portion of the first semiconductor region exposed to a side wall of the trench excluding a corner portion of the trench to be high; (c) forming a first electrode in the trench with a first insulator film interposed between the side wall of the trench and the first electrode, step (c) being conducted after the step (b); (d) forming a control electrode in the trench with a second insulator film interposed between the side wall of the trench and the control electrode, the control electrode being formed above the first electrode; and (e) diffusing the impurity of the first conductivity type introduced into the surface portion of the first semiconductor region for forming another semiconductor region of the first conductivity type on the side wall of the trench, the another semiconductor region being not so deep as to reach the corner portion of the trench, the another semiconductor region being doped more heavily than the first semiconductor region. - View Dependent Claims (10)
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Specification