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Manufacturing Method of Semiconductor Device

  • US 20090075433A1
  • Filed: 11/14/2008
  • Published: 03/19/2009
  • Est. Priority Date: 06/11/2003
  • Status: Active Grant
First Claim
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1. :

  • A manufacturing method of a semiconductor device comprising;

    forming a drift layer of a first conductivity on a first main surface of a semiconductor substrate of a first conductivity type, a surface of the drift layer having a first area for a cell portion and a second area for a terminating portion which is positioned on an outer periphery of the first area and alleviates an electric field to maintain a breakdown voltage by extending a depletion layer;

    forming a first insulating film with a first thickness in the second area on the drift layer, the first insulating film having first and second end portions, the first end portion being located closer to the first area than the second end surface;

    forming a second insulating film having a second thickness smaller than the first thickness in the first area on the drift layer;

    forming a control electrode on the second insulating film;

    forming a first base layer in the first area and a second base layer in the second area by implanting a second conductivity impurity into the drift layer using the control electrode and the first insulating film as a mask and then performing a heat treatment to diffuse the impurity;

    selectively forming an impurity diffused layer in a surface layer of the second base layer by implanting a second conductivity impurity into the second base layer and then performing a heat treatment to diffuse the impurity implanted into the second base layer, the impurity diffused layer having first and second opposing end surfaces, the first end surface being located closer to the first area than the second end surface;

    selectively forming a source layer of a first conductivity type in a surface layer of the first base layer; and

    forming first through third metallic compounds in surface layers of the source layer, of the control electrode and of the impurity diffused layer, respectively, by depositing a metallic material on the source layer, the control electrode and the impurity diffused layer, causing the source layer, the control electrode, the impurity diffused layer to react with the metallic material by a heat treatment, and then selectively removing the metallic material, the third metallic compound having third and fourth opposing end surfaces, the third end surface being located closer to the first area than the fourth end surface, and the fourth end surface being spaced from the second end surface of the impurity diffused region by a distance.

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