A semiconductor device includes a substrate comprising a semiconductor material. The substrate has a surface that defines a surface normal direction and includes a P-N junction comprising an interface between a first region and a second region, where the first (second) region includes a first (second) dopant type, so as to have a first (second) conductivity type. The substrate includes a termination extension region disposed adjacent to the P-N junction and having an effective concentration of the second dopant type that is generally the effective concentration of the second dopant type in the second doped region. The substrate includes an adjust region disposed adjacent to the surface and between the surface and at least part of the termination extension region, where the effective concentration of the second dopant type generally decreases when moving from the termination extension region into the adjust region along the surface normal direction.