×

Trench DMOS transistor having a zener diode for protection from electro-static discharge

  • US 6,657,256 B2
  • Filed: 05/22/2001
  • Issued: 12/02/2003
  • Est. Priority Date: 05/22/2001
  • Status: Expired due to Term
First Claim
Patent Images

1. A trench DMOS transistor having overvoltage protection, 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 and overlies said body region;

    a conductive electrode in the trench overlying the insulating layer;

    a source region of the first conductivity type in the body region adjacent to each trench;

    an undoped polysilicon layer overlying a portion of the insulating layer; and

    a plurality of cathode regions of the first conductivity type in the undoped polysilicon layer; and

    at least one anode region in contact with adjacent ones of the plurality of cathode regions.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×