SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME
First Claim
1. A manufacturing method of a semiconductor device, comprising:
- preparing a semiconductor substrate having a main surface and including a drift layer of a first conductivity type;
defining a trench in the semiconductor substrate from the main surface into the drift layer;
forming an adjustment layer at a portion of the semiconductor substrate adjacent to a bottom wall of the trench, the adjustment layer having a first conductivity type impurity concentration higher than the drift layer;
forming a gate insulating layer covering a sidewall and the bottom wall of the trench;
forming a channel layer by introducing second conductivity type impurities to a portion of the semiconductor substrate adjacent to the sidewall of the trench and between the adjustment layer and the main surface while restricting the channel layer from extending in a depth direction of the trench by the adjustment layer; and
embedding a gate electrode in the trench after the forming the gate insulating layer.
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Accused Products
Abstract
In a manufacturing method of a semiconductor device, a trench is defined in a semiconductor substrate, and an adjuster layer having a first conductivity type impurity concentration higher than a drift layer is formed at a portion of the semiconductor substrate adjacent to a bottom wall of the trench. A channel layer is formed by introducing second conductivity type impurities to a portion of the semiconductor substrate adjacent to a sidewall of the trench and between the adjustment layer and a main surface of the semiconductor substrate while restricting the channel layer from extending in a depth direction of the trench by the adjustment layer.
64 Citations
27 Claims
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1. A manufacturing method of a semiconductor device, comprising:
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preparing a semiconductor substrate having a main surface and including a drift layer of a first conductivity type; defining a trench in the semiconductor substrate from the main surface into the drift layer; forming an adjustment layer at a portion of the semiconductor substrate adjacent to a bottom wall of the trench, the adjustment layer having a first conductivity type impurity concentration higher than the drift layer; forming a gate insulating layer covering a sidewall and the bottom wall of the trench; forming a channel layer by introducing second conductivity type impurities to a portion of the semiconductor substrate adjacent to the sidewall of the trench and between the adjustment layer and the main surface while restricting the channel layer from extending in a depth direction of the trench by the adjustment layer; and embedding a gate electrode in the trench after the forming the gate insulating layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A manufacturing method of a semiconductor device, comprising:
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preparing a semiconductor substrate having a main surface and including a drift layer of a first conductivity type; defining a trench in the semiconductor substrate from the main surface into the drift layer; forming a channel layer shallower than the trench by implanting second conductivity type impurities from the main surface of the semiconductor substrate before or after the defining the trench; forming an adjustment layer at a portion of the semiconductor substrate located on a bottom wall of the trench and adjacent to the channel layer by introducing first conductivity type impurities at a higher concentration than the drift layer; forming a gate insulating layer covering a sidewall and the bottom wall of the trench; embedding a gate electrode in the trench after the forming the gate insulating layer, wherein the adjustment layer restricts the channel layer from extending in a depth direction of the trench.
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14. A semiconductor device comprising:
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a semiconductor substrate having a main surface and defining a trench from the main surface; a drift layer of a first conductivity type disposed at a portion in the semiconductor substrate adjacent to the trench; an adjustment layer disposed on the bottom wall of the trench and having a first conductivity type impurity concentration higher than the drift layer; a channel layer of a second conductivity type disposed at a portion of the semiconductor substrate adjacent to a sidewall of the trench and between the adjustment layer and the main surface; and a source layer or an emitter layer disposed on a portion of the sidewall of the trench adjacent to the main surface, the source layer or the emitter layer having a first conductivity type impurity concentration higher than the drift layer, wherein the adjustment layer restricts the channel layer from extending in a depth direction of the trench. - View Dependent Claims (15, 16)
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17. A manufacturing method of a semiconductor device, comprising:
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preparing a semiconductor substrate having a main surface and including a drift layer of a first conductivity type; defining a trench in the semiconductor substrate from the main surface into the drift layer; forming a gate insulating layer covering a sidewall and a bottom wall of the trench, the forming the gate insulating layer including forming a sidewall insulating layer on a sidewall of the trench and forming a bottom wall insulating layer thicker than the sidewall insulating layer on a bottom wall of the trench by selectively oxidizing the bottom wall of the trench after the forming the sidewall insulating layer; forming a channel layer along the sidewall of the trench by introducing second conductivity type impurities from the sidewall of the trench using the bottom wall insulating layer as a mask; and embedding a gate electrode in the trench after the forming the gate insulating layer. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification