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SEMICONDUCTOR DEVICE

  • US 20110059586A1
  • Filed: 11/11/2010
  • Published: 03/10/2011
  • Est. Priority Date: 12/10/2007
  • Status: Active Grant
First Claim
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1. A method for producing a semiconductor device, comprising:

  • forming a structure in which a trench gate structure is provided in a front surface side of semiconductor layers in which on a main surface of a first semiconductor layer of a first conductivity type, a second semiconductor layer of the first conductivity type that has a lower impurity concentration than that of the first semiconductor layer, a third semiconductor layer of a second conductivity type, and a fourth semiconductor layer of the first conductivity type are sequentially provided;

    forming a contact groove passing through the fourth semiconductor layer in the contiguous trench gate structures and reaching the third semiconductor layer; and

    forming a fifth semiconductor layer by introducing an impurity of the second conductive type into the second semiconductor layer by a plurality of times sequentially from a first introduction position in the second semiconductor layer not reaching the main surface of the first semiconductor layer to a shallower position therein in the third semiconductor layer side so that the fourth semiconductor layer in which the contact grooves are selectively formed serves as a mask,the fifth semiconductor layer being thinner from an uppermost portion to a lowermost portion, anda dose amount in impurity introduction into the first introduction position being higher than a dose amount of impurity introduction into the shallower position than the first introduction position.

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