Unpolished Semiconductor Wafer and Method For Producing An Unpolished Semiconductor Wafer

Abstract

Unpolished semiconductor wafers are produced by: (a) pulling a single crystal of a semiconductor material, (b) grinding the single crystal round, (c) separating a semiconductor wafer from this crystal, (d) rounding the edge of the semiconductor wafer, (e) surface-grinding at least one side of the semiconductor wafer, (f) treating the semiconductor wafer with an etchant, and (g) cleaning the semiconductor wafer. The unpolished semiconductor wafers have, on at least the front side, a reflectivity of 95% or more, a surface roughness of 3 nm or less, have a thickness of 80-2500 μm, an overall planarity value GBIR of 5 μm or less with an edge exclusion of 3 mm and a photolithographic resolution of at least 0.8 μm, and which furthermore contain a native oxide layer with a thickness of 0.5-3 nm on both sides.

1 .- 24 . (canceled) 
     
     
         25 . An unpolished semiconductor wafer having a front side and a rear side, wherein at least its front side is ground and its front and rear sides are etched, which has a reflectivity of 95% or more at least on its front side, a surface roughness of 3 nm or less at least on its front side, a thickness of 80-2500 μm, a global planarity value GBIR of 5 μm or less based on an edge exclusion of 3 mm and which allows a photolithographic resolution of at least 0.8 μm, and which furthermore contains a native oxide layer with a thickness of 0.5-3 nm on its front and rear sides. 
     
     
         26 . The unpolished semiconductor wafer of  claim 25 , which is a monocrystalline silicon wafer. 
     
     
         27 . The unpolished semiconductor wafer of  claim 25 , which has no damage, craters, plastic residue or other defects that can be detected by means of a visual inspection. 
     
     
         28 . The unpolished semiconductor wafer of  claim 25 , on which no particles are visible under visual observation with collimated light. 
     
     
         29 . The unpolished semiconductor wafer of  claim 25 , wherein the rear side of the semiconductor wafer is likewise ground and etched. 
     
     
         30 . The unpolished semiconductor wafer of  claim 25 , which contains metallic contaminations in a concentration of 10 13  cm −2  or less. 
     
     
         31 . The unpolished semiconductor wafer of  claim 25 , which is of the p or n conduction type and has a 1-0-0, 1-1-0 or 1-1-1 crystal orientation in its bulk, a resistance range of 0.001-100,000 Ohm·cm and a resistance tolerance of less than ±10%. 
     
     
         32 . The unpolished semiconductor wafer of  claim 25 , which has a thickness of 100-500 μm. 
     
     
         33 . The unpolished semiconductor wafer of  claim 25 , which has a thickness of 80-100 μm. 
     
     
         34 . The unpolished semiconductor wafer of  claim 25 , which has a global planarity value GBIR of 0.5 to 3 μm. 
     
     
         35 . The unpolished semiconductor wafer of  claim 25 , which has a reflectivity ≧98%. 
     
     
         36 . The unpolished semiconductor wafer of  claim 25  which as ≦10 13  cm −2  of metallic contamination measured by means of VPD-TXRF or VPD-IC-MS.