Patent ID: 9508870
Filing Date: 2016-11-29
CPC Classification: H01L

Claim Text:
1. A diode comprising: an n-type drift layer; a p-type anode layer on the n-type drift layer in an active region; a p-type diffusion layer on the n-type drift layer in a termination region outside the active region; a first insulating film covering an outer periphery of the p-type anode layer; an anode electrode connected to a portion of the p-type anode layer not covered with first insulating film; an n-type cathode layer below the n-type drift layer; and a cathode electrode connected to the n-type cathode layer, wherein an area of a portion of the p-type anode layer covered with the first insulating film is 5 to 30% of a total area of the p-type anode layer, wherein the p-type anode layer includes a first region and a second region which is provided around a periphery of the first region, the second region having a depth that is deeper than a depth of the first region and the second region having an impurity concentration that is higher than an impurity concentration of the first region, wherein a width of the second region is larger than a width of a portion of the p-type anode layer covered with the first insulating film, wherein the depth of the second region decreases toward an outside of a chip, wherein the second region has a first depth at a first point near one end and a second depth at a second point near another end nearer to the termination region than the one end, wherein the first depth is greater than the second depth, and wherein the depth of the second region changes uniformly from the first point to the second point.