Method for Manufacturing a Semiconductor Device by Hydrogen Treatment

Abstract

A method of manufacturing a semiconductor device includes: forming a porous area at a surface of a semiconductor body; forming a semiconductor layer on the porous area by epitaxial growth; forming semiconductor regions including source, drain, body, emitter, base and/or collector regions in a front surface of the semiconductor layer, wherein the front surface of the semiconductor layer corresponds to a front side of the semiconductor device; introducing, after forming the semiconductor regions, hydrogen into the porous area by a thermal treatment, wherein the semiconductor layer with the semiconductor regions is separated from the semiconductor body along the porous area; and applying, after separation of the semiconductor layer, rear side processing to the semiconductor layer, wherein a rear side of the semiconductor layer corresponds to a rear side of the semiconductor device.

What is claimed is: 
     
         1 . A method of manufacturing a semiconductor device, the method comprising:
 forming a porous area at a surface of a semiconductor body;   forming a semiconductor layer on the porous area by epitaxial growth;   forming semiconductor regions including source, drain, body, emitter, base and/or collector regions in a front surface of the semiconductor layer, wherein the front surface of the semiconductor layer corresponds to a front side of the semiconductor device;   introducing, after forming the semiconductor regions, hydrogen into the porous area by a thermal treatment, wherein the semiconductor layer with the semiconductor regions is separated from the semiconductor body along the porous area; and   applying, after separation of the semiconductor layer, rear side processing to the semiconductor layer, wherein a rear side of the semiconductor layer corresponds to a rear side of the semiconductor device.   
     
     
         2 . The method of  claim 1 , wherein the hydrogen is introduced into the porous area by diffusion of the hydrogen through the semiconductor layer into the porous area. 
     
     
         3 . The method of  claim 1 , wherein the semiconductor body is one of Si and SiC. 
     
     
         4 . The method of  claim 1 , wherein forming the porous area of the semiconductor body comprises anodic dissolution of the semiconductor body. 
     
     
         5 . The method of  claim 4 , wherein the anodic dissolution of the semiconductor body comprises anodic dissolution of silicon in a chemical mixture of hydrofluoric acid and ethanol or acetic acid. 
     
     
         6 . The method of  claim 4 , wherein forming the porous area comprises forming a double porosity structure including a first porous area in the semiconductor body which has a first porosity and a second porous area deeper within the semiconductor body which has a second porosity, wherein the first porosity is smaller than the second porosity. 
     
     
         7 . The method of  claim 6 , wherein the porosity of the first porous area is set in a range between 10% and 50% and the porosity of the second porous area is set in a range between the porosity of the first porous area and 80%. 
     
     
         8 . The method of  claim 1 , wherein forming the semiconductor regions in the semiconductor layer comprises forming at least one of n-type and p-type regions in the semiconductor layer by introducing impurities into the semiconductor layer. 
     
     
         9 . The method of  claim 1 , further comprising forming a trench in at least one of the semiconductor body and in the semiconductor layer. 
     
     
         10 . The method of  claim 1 , wherein the semiconductor layer has a thickness in a range from 5 μm to 200 μm. 
     
     
         11 . The method of  claim 1 , wherein the rear side processing comprises at least one of ion implantation and laser anneal. 
     
     
         12 . A method of manufacturing a semiconductor device, the method comprising:
 forming a porous area at a surface of a semiconductor body, wherein the porous area has a porous structure;   forming a semiconductor layer on the porous area by epitaxial growth;   forming, by ion implantation, semiconductor regions including source, drain, body, emitter, base and/or collector regions in a front side of the semiconductor layer, wherein the front surface of the semiconductor layer forms a front side surface of a semiconducting portion of the semiconductor device;   introducing, after forming the semiconductor regions, hydrogen into the porous area by ion-implantation, wherein the semiconductor layer with the semiconductor regions is separated from the semiconductor body along the porous area; and   applying, after separation of the semiconductor layer, rear side processing comprising ion_implantation to the semiconductor layer, wherein a rear side of the semiconductor layer defines a rear side surface of the semiconducting portion and a thickness of the semiconductor layer defines a thickness of the semiconductor portion.   
     
     
         13 . The method of  claim 12 , wherein an implant dose of the hydrogen is in a range of 5·10 14  cm −2  to 5·10 15  cm −2 . 
     
     
         14 . The method of  claim 12 , wherein an implant energy of the ion implantation is in the range of 150 keV to 4 MeV. 
     
     
         15 . The method of  claim 12 , wherein forming the porous area of the semiconductor body comprises anodic dissolution of the semiconductor body. 
     
     
         16 . The method of  claim 15 , wherein the anodic dissolution of the semiconductor body comprises anodic dissolution of silicon in a chemical mixture of hydrofluoric acid and ethanol or acetic acid. 
     
     
         17 . The method of  claim 15 , wherein forming the porous area comprises forming a double porosity structure including a first porous area in the semiconductor body which has a first porosity and a second porous area deeper within the semiconductor body which has a second porosity, wherein the first porosity is smaller than the second porosity. 
     
     
         18 . The method of  claim 17 , wherein the porosity of the first porous area is set in a range between 10% and 50% and the porosity of the second porous area is set in a range between the porosity of the first porous area and 80%.