Insulated gate semiconductor device with high minority carrier injection and low on-voltage by enlarged pn-junction area
First Claim
1. A trench-gate-type semiconductor device comprising:
- a first conductive-type semiconductor region having a first surface and a second surface opposite to the first surface, and made from a first conductive-type semiconductor material into which carriers are injected from a channel formed of a gate electrode formed in a trench solely on the first surface;
a second conductive-type semiconductor region made from a second conductive-type semiconductor material and formed in such a manner as to contact the second surface of the first conductive-type semiconductor region; and
a convexo-concave portion formed on a contact surface between the first and second conductive-type semiconductor regions.
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Accused Products
Abstract
A semiconductor device is formed such that a contact surface between a p-type high-concentration semiconductor region and an n-type high-concentration buffer region assumes a convexo-concave shape. This makes it possible to enlarge an area of the contact surface between the p-type high-concentration semiconductor region and the n-type high-concentration buffer region. As a result, holes are injected into an n-type low-concentration drift region from the p-type high-concentration semiconductor region with higher efficiency and with a less voltage drop between the pn-junction. Thus, effects of conductivity modulation can be achieved sufficiently and the on-resistance and the voltage drop of an IGBT can be lowered.
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Citations
14 Claims
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1. A trench-gate-type semiconductor device comprising:
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a first conductive-type semiconductor region having a first surface and a second surface opposite to the first surface, and made from a first conductive-type semiconductor material into which carriers are injected from a channel formed of a gate electrode formed in a trench solely on the first surface;
a second conductive-type semiconductor region made from a second conductive-type semiconductor material and formed in such a manner as to contact the second surface of the first conductive-type semiconductor region; and
a convexo-concave portion formed on a contact surface between the first and second conductive-type semiconductor regions. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A semiconductor device comprising:
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a first conductive-type semiconductor region having a first surface and a second surface opposite to the first surface, and made from a first conductive-type semiconductor material in which carriers are injected from a channel formed of a gate electrode solely on the first surface; and
a second conductive-type semiconductor region made from a second conductive-type semiconductor material and formed in such a manner as to contact the second surface of the first conductive-type semiconductor region, wherein an average interface of a contact surface between the first and second conductive-type semiconductor regions is formed in such a manner as to form a predetermined angle with the channel, and the contact surface is formed in a convexo-concave shape. - View Dependent Claims (8, 9, 10)
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11. A method of manufacturing a trench-gate-type semiconductor device comprising a first conductive-type semiconductor region having a first surface and a second surface opposite to the first surface, and made from a first conductive-type semiconductor material into which carriers are injected from a channel formed of a gate electrode formed in a trench solely on the first surface and a second conductive-type semiconductor region made from a second conductive-type semiconductor material and formed in such a manner as to contact the second surface of the first conductive-type semiconductor region, comprising:
a semiconductor area forming process in which the first conductive-type semiconductor region and/or the second conductive-type semiconductor region are/is formed such that a contact surface between the first and second conductive-type semiconductor regions assumes a convexo-concave shape. - View Dependent Claims (12, 13, 14)
Specification