TRENCH MOSEFT WITH TRENCH GATES UNDERNEATH CONTACT AREAS OF ESD DIODE FOR PREVENTION OF GATE AND SOURCE SHORTATE
First Claim
1. A trench DMOS transistor having overvoltage protection with prevention of shortage between gate and source from ESD, comprising:
- a substrate of a first conductivity type;
a body region on the substrate, said body region having a second conductivity type;
a source region of the first conductivity type in said body region adjacent to each trench in DMOS area;
a conductive electrode in the trench overlying the insulating layer;
a gate oxide layer that lines along the trench and an insulating layer overlies said body region;
a ESD protection diode on top of said insulating layer; and
trench gates underneath contact areas of said ESD diode;
1 Assignment
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Accused Products
Abstract
A trench DMOS transistor having overvoltage protection and prevention for shortage between gate and source when contact trenches are applied includes a substrate of a first conductivity type and a body region of a second conductivity type formed over the substrate. Trench gates extend through the body region and the substrate. An insulating oxide layer lines the trench and overlies the body region. A conductive electrode is deposited in the trench so that it overlies the insulating layer. A source region of the first conductivity type is formed in the body region adjacent to the trench. An undoped polysilicon layer overlies a portion of the insulating layer defining the Zener diode region. A plurality of cathode regions of the first conductivity type is formed in undoped polysilicon layer. At least one anode region is in contact with adjacent ones of the plurality of cathode regions. Trench gates underneath the Zener diode act as the buffer layer for prevention of shortage between gate and source.
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Citations
8 Claims
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1. A trench DMOS transistor having overvoltage protection with prevention of shortage between gate and source from ESD, comprising:
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a substrate of a first conductivity type; a body region on the substrate, said body region having a second conductivity type; a source region of the first conductivity type in said body region adjacent to each trench in DMOS area; a conductive electrode in the trench overlying the insulating layer; a gate oxide layer that lines along the trench and an insulating layer overlies said body region; a ESD protection diode on top of said insulating layer; and trench gates underneath contact areas of said ESD diode; - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification