Patent ID: 8659082

Claim:
A method for manufacturing a semiconductor device having a super junction structure, the method comprising: preparing a semiconductor substrate having a first conductive type; forming a plurality of trenches in the substrate, wherein each trench has a constant width along a first direction, and wherein a distance between neighboring two trenches along the first direction includes at least a first distance and a second distance; forming an epitaxial film having a second conductive type on the substrate so that the trenches are filled with the epitaxial film; and flattening one side of the substrate, on which the epitaxial film is formed, wherein the epitaxial film in each trench provides a first column, and part of the semiconductor substrate between two neighboring trenches provides a second column, so that the first columns and the second columns are alternately arranged in the first direction, which is perpendicular to a current flowing direction, wherein each first column provides a drift layer for flowing current through during an on-state, wherein each pair of adjacent first and second columns has a boundary from which a depletion layer expands during an off-state, and wherein, in at least one of the first columns and the second columns, in a transistor-forming area, a total amount of impurities in corresponding columns are different by location with respect to the first direction.