Area efficient high voltage Mosfets with vertical resurf drift regions
AssigneeTexas Instruments Incorporated
InventorSatwinder Malhi
Life of this patent
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Abstract
A high voltage power transistor cell is developed that provides improved RDSon performance without sacrificing breakdown performance through utilization of trench based transistor technology. A source, drain and trench are formed within a substrate. A gate is formed on the surface over a spacing between the source and the trench. A drift region is formed around the trench. An isolation region may optionally be added allowing electrical isolation between the source and the substrate. The lateral current flow feature allows multiple high voltage power transistors, electrically isolated from one another, to exist on a single semiconductor chip. The drift region formed around the trench provides RESURF transistor characteristics without sacrificing die area.
Claims7
A lateral power transistor, comprising:
- source;
- gate;
- drain;
- trench disposed between the gate and the drain;
- and
- drift region surrounding the trench.
A power transistor, comprising:
- a substrate;
- a body region formed in the substrate;
- a source region formed in the body;
- a gate;
- a drain region formed in the substrate;
- a trench formed in the face of the substrate between the source region and the drain region;
- and
- a drift region encircling the trench.
Dependencies are inferred from the claim text.