Semiconductor device having a super junction structure and method of manufacturing the same

Abstract

A semiconductor device having a super junction and a method of manufacturing the semiconductor device capable of obtaining a high breakdown voltage are provided, whereby charge balance of the super junction is further accurately controlled in the semiconductor device that is implemented by an N-type pillar and a P-type pillar. The semiconductor device includes a semiconductor substrate; and a blocking layer including a first conductive type pillar and a second conductive type pillar that extend in a vertical direction on the semiconductor substrate and that are alternately arrayed in a horizontal direction, wherein, in the blocking layer, a density profile of a first conductive type dopant may be uniform in the horizontal direction, and the density profile of the first conductive type dopant may vary in the vertical direction.

What is claimed is: 
     
         1 . A method of manufacturing a semiconductor device having a super junction, the method comprising:
 epitaxially forming a first undoped epitaxial layer on a semiconductor substrate;   implanting dopants of a first conductive type in the first undoped epitaxial layer to form a first doped layer of the first conductive type;   implanting dopants of a second conductive type in predetermined portions of the first doped layer;   epitaxially forming a second undoped epitaxial layer on the first doped layer;   implanting dopants of the first conductive type in the second undoped epitaxial layer to form a second doped layer of the first conductive type;   implanting dopants of the second conductive type in predetermined portions of the second doped layer; and   diffusing dopants from at least the first and second doped layers to form a blocking layer comprising a first conductive type pillar and a second conductive type pillar that extend in a vertical direction on the semiconductor substrate and that are alternately arrayed in a horizontal direction.   
     
     
         2 . The method of  claim 1 , wherein the first conductive type is N-type and the second conductive type is P-type. 
     
     
         3 . The method of  claim 1 , wherein a density profile of dopants of the first conductive type is uniform in the horizontal direction in both the first and second conductive type pillars in the blocking layer. 
     
     
         4 . The method of  claim 1 , wherein diffusing dopants from at least the first and second doped layers is by thermal treatment. 
     
     
         5 . The method of  claim 1 , wherein a density profile of dopants of the first conductive type is uniform in the horizontal direction in both the first and second conductive type pillars, and the density profile of dopants of the first conductive type varies in the vertical direction in the blocking layer. 
     
     
         6 . The method of  claim 1 , further comprising:
 before diffusing dopants from at least the first and second doped layers to form the blocking layer, epitaxially forming a third undoped epitaxial layer on the second doped layer, implanting dopants of the first conductive type in the third undoped epitaxial layer to form a third doped layer of the first conductive type,   wherein the blocking layer is formed by diffusing dopants from at least the first, second, and third doped layers.   
     
     
         7 . The method of  claim 1 , wherein the first undoped epitaxial layer is formed to a first thickness and the third undoped epitaxial layer is formed to a second thickness that is thinner than the first thickness. 
     
     
         8 . The method of  claim 1 , wherein the first undoped epitaxial layer is formed to a same thickness as the third undoped epitaxial layer. 
     
     
         9 . A method of manufacturing a semiconductor device having a super junction, the method comprising:
 preparing a semiconductor substrate;   forming an undoped epi-layer on the semiconductor substrate;   forming a first conductive type implant layer by implanting a first conductive type dopant in an entire top surface of the undoped epi-layer;   forming a second conductive type implant layer by implanting a second conductive type dopant in a predetermined portion of the first conductive type implant layer; and   forming a first conductive type pillar and a second conductive type pillar by diffusing a dopant of the first conductive type implant layer and a dopant of the second conductive type implant layer to the undoped epi-layer by performing a thermal treatment.   
     
     
         10 . The method of  claim 9 , wherein the first conductive type pillar and the second conductive type pillar form a blocking layer by extending in a vertical direction on the semiconductor substrate and by being alternately arrayed in a horizontal direction, on the semiconductor substrate, and
 the blocking layer is formed whereby density of the first conductive type dopant varies according to heights in the vertical direction, and the density of the first conductive type dopant is uniform in the horizontal direction at a same height.   
     
     
         11 . The method of  claim 9 , further comprising forming a first conductive type epi-layer on the semiconductor substrate.