×

Trench-gate transistors and their manufacture

  • US 8,222,693 B2
  • Filed: 03/03/2008
  • Issued: 07/17/2012
  • Est. Priority Date: 03/10/2004
  • Status: Active Grant
First Claim
Patent Images

1. A transistor circuit comprising:

  • a semiconductor body;

    a plurality of transistor cells in the body, each cell having a channel region in the body and, underlying the channel region, a drain drift region;

    an array of trenches extending from an upper surface of the semiconductor body, each trench extending through one of the channel regions and into an underlying drain drift region; and

    in each trench,a gate dielectric insulating layer extending from an upper surface of the semiconductor body, over a top corner of the trench and along a sidewall of the trench adjacent to both the channel region and the drain drift region;

    a layer of silicon nitride laterally adjacent a portion of the gate dielectric insulating layer that is adjacent the drain drift region;

    a layer of silicon dioxide laterally adjacent a portion of the gate dielectric insulating layer that is adjacent the drain drift region;

    a gate immediately laterally adjacent a portion of the gate dielectric insulating layer that is adjacent the channel region; and

    a field plate below the gate and separated from a portion of the gate dielectric insulating layer that is adjacent the drain drift region by the respective layers of silicon nitride and silicon dioxide.

View all claims
  • 11 Assignments
Timeline View
Assignment View
    ×
    ×