Superjunction semiconductor device
In accordance with an embodiment of the invention, a superjunction semiconductor device includes an active region and a termination region surrounding the active region. A central vertical axis of a boundary column of a second conductivity type material defines the boundary between the active region and the termination region. The active and termination regions include columns of first and second conductivity type material alternately arranged along a horizontal direction in a semiconductor region having top and bottom surfaces. At least one of the columns of the first conductivity type material in the termination region has a different width than a width of the columns of the first conductivity type material in the active region.
1. A superjunction semiconductor device having an active region and a termination region surrounding the active region, a central vertical axis of a boundary column of a second conductivity type material defining the boundary between the active region and the termination region, wherein the active region and the termination region include columns of first conductivity type material and columns of second conductivity type material alternately arranged on both sides of the boundary column in a semiconductor region having top and bottom surfaces, wherein in the active region, a first conductivity type charge quantity in each of the columns of first conductivity type material is greater than a second conductivity type charge quantity in each of the columns of second conductivity type material,
wherein a difference between a first conductivity type charge quantity within a first column of the first conductivity type material in the termination region adjoining the boundary column and the sum of a second conductivity type charge quantity in one half of the boundary column and one half of a second column of the second conductivity type material in the termination region adjoining the first column is less than the difference between a first conductivity type charge quantity within a third column of the first conductivity type material in the active region adjoining the boundary column and the sum of a second conductivity type charge quantity in one half of the boundary column and one half of a fourth column of the second conductivity type material in the active region adjoining the third column.
2. The superjunction semiconductor device of claim 1 wherein the active region further comprises a plurality of planar-gate structures formed along the top surface of the semiconductor region.
3. A superjunction semiconductor device having an active region and a termination region surrounding the active region, a central vertical axis of a boundary column of a second conductivity type material defining the boundary between the active region and the termination region, the active and termination regions including columns of first and second conductivity type material alternately arranged along a horizontal direction in a semiconductor region having top and bottom surfaces, wherein in the active region, a width of each of the columns of first conductivity type material is greater than a width of each of the columns of second conductivity type material,
wherein a spacing between the central vertical axis of the boundary column and a central vertical axis of a first column of the second conductivity type material in the termination region located closest to the boundary column is less than the spacing between the central vertical axis of the boundary column and a central vertical axis of a second column of the second conductivity type material in the active region located closest to the boundary column.
4. The superjunction semiconductor device of claim 3 , wherein the spacing between the central vertical axes of adjacent columns of the second conductivity type material in the termination region varies along a horizontal direction.
5. The superjunction semiconductor device of claim 3 , wherein the spacing between the central vertical axes of adjacent ones of at least three columns of the second conductivity type material in the termination region becomes progressively greater in a direction away from the active region.
6. The superjunction semiconductor device of claim 3 , wherein the first conductivity type is n-type, and the second conductivity type is p-type.
7. The superjunction semiconductor device of claim 3 wherein the active region further comprises a plurality of planar-gate structures formed along the top surface of the semiconductor region.