SOI wafer and method for producing the same

Abstract

The present invention provides a SOI wafer produced by an ion implantation delamination method wherein a width of a SOI island region in a terrace portion generated in an edge portion of the SOI wafer where a surface of a base wafer is exposed is narrower than 1 mm and a density of pit-shaped defects having a size of 0.19 μm or more existing in a surface of a SOI layer detected by a LPD inspection is 1 counts/cm 2 or less, and also provides a method for producing the SOI wafer. Thereby, there is provided a SOI wafer produced by an ion implantation delamination method wherein generation of SOI islands generated in delamination can be suppressed and a defect density of LPDs existing in a surface of the SOI wafer can be reduced, and a method for producing the same, so that device failure can be reduced.

1 . A SOI wafer produced by an ion implantation delamination method wherein a density of pit-shaped defects having a size of 0.19 μm or more existing in a surface of a SOI layer detected by a LPD inspection is 1 counts/cm 2  or less.  
   
   
       2 . A method for producing a SOI wafer by an ion implantation delamination method wherein a lower limit of an implantation dosage of hydrogen ions or rare gas ions is determined by a delamination phenomenon, and an upper limit of an implantation dosage of hydrogen ions or rare gas ions is determined by a width of a SOI island region in a terrace portion or a density of pit-shaped defects detected by a LPD inspection of the SOI wafer.  
   
   
       3 . A method for producing a SOI wafer by an ion implantation delamination method wherein an implantation dosage of hydrogen ions is 5×10 16  ions/cm 2  or more and less than 7.5×10 16 /cm 2 .