Patent ID: 7754009
Filing Date: 2010-07-13
Classification: C30B

Abstract:
1. A method for producing an unpolished semiconductor wafer, which comprises the following steps, in the order given: (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 both sides of the semiconductor wafer by a first coarse grinding followed by a second fine grinding, (f) treating the semiconductor wafer with an etchant, and (g) cleaning the semiconductor wafer, wherein the unpolished wafer has 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.