Patent ID: 8642401
Filing Date: 2014-02-04
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device including an IGBT, comprising the steps of: (a) providing a semiconductor substrate of a first conductivity type; (b) forming a first trench in the semiconductor substrate; (c) embedding a first conductive film in the first trench; (d) forming a first impurity region of a second conductivity type opposite the first conductivity type in the semiconductor substrate, wherein a depth of the first impurity region is shallower than a depth of the first trench; (e) forming a second impurity region of the first conductivity type in the semiconductor substrate, wherein a depth of the second impurity region is shallower than the depth of the first impurity region; (f) forming a first insulating film over the second impurity region; (g) forming a second trench by using the first insulating film as a mask in the semiconductor substrate, wherein the second trench penetrates the second impurity region and reaches the first semiconductor impurity region, and wherein a depth of the second trench is shallower than a depth of the first trench; (h) forming a third impurity region of the second conductivity type in the first impurity region located at a bottom of the second trench, wherein an impurity concentration of the third impurity region is higher than an impurity concentration of the first impurity region; (i) after step (h), recessing the first insulating film, thereby a portion of a surface of the second impurity region is exposed; and (j) after step (i), forming a first metal film in the second trench, wherein the first metal film is electrically connected with the exposed surface of the second impurity region outside of the second trench and is electrically connected with the first, second, and third impurity regions inside of the second trench.