×

High frequency switching MOSFETs with low output capacitance using a depletable P-shield

  • US 9,502,554 B2
  • Filed: 01/22/2016
  • Issued: 11/22/2016
  • Est. Priority Date: 12/21/2012
  • Status: Active Grant
First Claim
Patent Images

1. A MOSFET device, comprising:

  • a semiconductor substrate of a first conductivity type wherein the substrate includes a lightly doped epitaxial region in a top portion of the substrate;

    a body region of a second conductivity type formed in a top portion of the semiconductor substrate, wherein the second conductivity type is opposite the first conductivity type;

    a plurality of active device structures formed from the semiconductor substrate and body region, wherein each active device structure in the plurality of active device structures comprises a gate electrode in a gate trench formed in the semiconductor substrate, wherein the gate electrode is insulated from the substrate and body region by a gate oxide, whereby there are a plurality of gate electrodes in a corresponding plurality of gate trenches;

    a depletable shield of the second conductivity type formed in the semiconductor substrate between first and second gate trenches of the plurality of gate trenches and extending vertically from above a gate trench bottom down to below the gate trench bottom and separated from the body region by a drift region of the first conductivity type, wherein the depletable shield is electrically connected to the body region;

    an insulative layer over a top surface of the body region;

    a conductive source metal layer formed over the insulative layer; and

    one or more electrical connections that connect the source metal layer with one or more source regions.

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