Method of fabricating an SOI wafer and SOI wafer fabricated by the method

Abstract

There is disclosed a method of fabricating an SOI wafer wherein an oxide film is formed on at least one of two single crystal silicon wafers; hydrogen ions or rare gas ions are implanted into the upper surface of one of the two silicon wafers in order to form an ion implanted layer; the ion-implanted surface is brought into close contact with the surface of the other silicon wafer via the oxide film; heat treatment is performed to separate a thin film from the silicon wafer with using the ion implanted layer as a delaminating plane to fabricate the SOI wafer having an SOI layer; and then an epitaxial layer is grown on the SOI layer to form a thick SOI layer. There is provided an SOI wafer which has a thick SOI layer with good thickness uniformity and good crystallinity and which is useful for a bipolar device or a power device.

What is claimed is:  
     
         1 . A method of fabricating an SOI wafer wherein an oxide film is formed on at least one of two single crystal silicon wafers; hydrogen ions or rare gas ions are implanted into the upper surface of one of the two silicon wafers in order to form an ion implanted layer; the ion-implanted surface is brought into close contact with the surface of the other silicon wafer via the oxide film; heat treatment is performed to separate a thin film from the silicon wafer with using the ion implanted layer as a delaminating plane to fabricate the SOI wafer having an SOI layer; and then an epitaxial layer is grown on the SOI layer to form a thick SOI.  
     
     
         2 . The method of fabricating an SOI wafer according to    claim 1    wherein the SOI wafer before the growth of the epitaxial layer is subjected to a heat treatment in a reducing atmosphere including hydrogen or in an atmosphere including hydrogen chloride gas.  
     
     
         3 . The method of fabricating an SOI wafer according to    claim 1    wherein the thickness of the SOI layer of the SOI wafer before growth of the epitaxial layer is 0.2 μm or more.  
     
     
         4 . The method of fabricating an SOI wafer according to    claim 2    wherein the thickness of the SOI layer of the SOI wafer before growth of the epitaxial layer is 0.2 μm or more.  
     
     
         5 . The method of fabricating an SOI wafer according to    claim 1    wherein the thickness of the thick SOI layer after the epitaxial growth is 2 μm or more.  
     
     
         6 . The method of fabricating an SOI wafer according to    claim 2    wherein the thickness of the thick SOI layer after the epitaxial growth is 2 μm or more.  
     
     
         7 . The method of fabricating an SOI wafer according to    claim 3    wherein the thickness of the thick SOI layer after the epitaxial growth is 2 μm or more.  
     
     
         8 . An SOI wafer fabricated by the method according to    claim 1   .  
     
     
         9 . An SOI wafer fabricated by the method according to    claim 2   .  
     
     
         10 . An SOI wafer fabricated by the method according to    claim 3   .  
     
     
         11 . An SOI wafer fabricated by the method according to    claim 4   .  
     
     
         12 . An SOI wafer fabricated by the method according to    claim 5   .  
     
     
         13 . An SOI wafer fabricated by the method according to    claim 6   .  
     
     
         14 . An SOI wafer fabricated by the method according to    claim 7   .  
     
     
         15 . A method for reusing a delaminated wafer produced as a by-product in the method according to    claim 1    as a silicon wafer after reprocessing it.  
     
     
         16 . A method for reusing a delaminated wafer produced as a by-product in the method according to    claim 2    as a silicon wafer after reprocessing it.  
     
     
         17 . A method for reusing a delaminated wafer produced as a by-product in the method according to    claim 3    as a silicon wafer after reprocessing it.  
     
     
         18 . A method for reusing a delaminated wafer produced as a by-product in the method according to    claim 5    as a silicon wafer after reprocessing it.  
     
     
         19 . A thick layer SOI wafer fabricated by growing an epitaxial layer on an SOI layer wherein a damage layer is present in the SOI layer under the epitaxial layer.