Patent ID: 8653586

Claim:
A superjunction device, comprising an N+ substrate and an N-type epitaxial layer formed on the N+ substrate, a transition region existing in the N-type epitaxial layer and being adjacent to a surface of the N+ substrate, a central area of the superjunction device being defined as an active region, a peripheral area of the superjunction device surrounding the active region being defined as a terminal protection region, wherein the superjunction device further comprises: a plurality of parallelly arranged first trenches formed in the N-type epitaxial layer in the active region, a P-type impurity being filled into the first trenches to form a plurality of P-type pillars, the P-type pillars and the N-type epitaxial layer forming alternately arranged P-type and N-type regions; and a plurality of second trenches surrounding the active region formed in the N-type epitaxial layer in the terminal protection region, a P-type impurity being filled into the second trenches to form a plurality of P-type annular columns, the P-type annular columns and the N-type epitaxial layer forming alternately arranged P-type and N-type regions; wherein none of the P-type pillars in the active region is in contact with the N+substrate, and a distance between the surface of the N+ substrate and a bottom of any one of the P-type pillars in the active region is greater than a thickness of the transition region.