Trench DMOS transistor having lightly doped source structure
AssigneeGeneral Semiconductor, Inc.
InventorsFwu-Iuan Hshieh, Koon Chong So, Yan Man Tsui
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Abstract
A trench DMOS transistor cell includes a substrate of a first conductivity type and a body region located on the substrate, which has a second conductivity type. At least one trench extends through the body region and the substrate. An insulating layer lines the trench and a conductive electrode is placed in the trench overlying the insulating layer. A source region of the first conductivity type is located in the body region adjacent to the trench. The source region includes a first layer and a second layer disposed over the first layer. The first layer has a lower dopant concentration of the first conductivity type relative to the dopant concentration of the second layer.
Claims28
A trench DMOS transistor cell, comprising:
- a substrate of a first conductivity type;
- a body region on the substrate, said body region having a second conductivity type;
- at least one trench extending through the body region and the substrate;
- an insulating layer that lines the trench;
- a conductive electrode in the trench overlying the insulating layer;
- and
- a source region of the first conductivity type in the body region adjacent to the trench, said source region including a first layer and a second layer disposed over said first layer, said first layer having a lower dopant concentration of the first conductivity type relative to the dopant concentration of the second layer.
A trench DMOS transistor structure that includes a plurality of individual trench DMOS transistor cells formed on a substrate of a first conductivity type, each of said individual trench DMOS transistor cells comprising:
- a substrate of a first conductivity type;
- a body region on the substrate, said body region having a second conductivity type;
- at least one trench extending through the body region and the substrate;
- an insulating layer that lines the trench;
- a conductive electrode in the trench overlying the insulating layer;
- and
- a source region of the first conductivity type in the body region adjacent to the trench, said source region including a first layer and a second layer disposed over said first layer, said first layer having a lower dopant concentration of the first conductivity type relative to the dopant concentration of the second layer.
Dependencies are inferred from the claim text.