Patent ID: 7662705

Claim:
A partial implantation method to implant dopant ions at different densities into a plurality of regions, including first and second regions, defined in a wafer by means of a boundary line, the method comprising: defining a first implantation zone as a remaining part of the first region excluding a specific part of the first region close to the boundary line, a second implantation zone as a remaining part of the second region except for a specific part of the second region close to the boundary line, and a third implantation zone as a remaining part of the wafer including the boundary line, excluding the first and second implantation zones; and implanting dopant ions at a first density into the first implantation zone, at a second density different from the first density into the second implantation zone, and at a third density between the first and second densities into the third implantation zone, wherein a slope of the density of dopants in the third implantation zone can be adjusted by varying the area of at least one of the first and second implantation zones.