Method for producing discs from a cylindrical rod made of a semiconductor material
AssigneeSiltronic AG
InventorsGeorg Pietsch, Joachim Junge
Life of this patent
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Abstract
A method produces wafers from a cylindrical ingot of semiconductor material having an axis and an indexing notch in an outer surface of the cylindrical ingot and parallel to the axis. The method includes, in the order specified: (a) simultaneous removal of a multiplicity of sliced wafers from the cylindrical ingot by multi-wire slicing in the presence of a cutting agent; (b) etching of the sliced wafers with an alkaline etchant in an etching bath at a temperature of 20° C. to 50° C. and for a residence time, such that the material removed from each of the sliced wafers is less than 5/1000 of an initial wafer thickness; and (c) grinding of the etched wafers by simultaneous double-disk grinding using an annular abrasive covering.
Claims16
A method for producing wafers from a cylindrical ingot of semiconductor material having an axis and an indexing notch in an outer surface of the cylindrical ingot and parallel to the axis, the method comprising, in the order specified:
- (a) simultaneous removal of a multiplicity of sliced wafers from the cylindrical ingot by multi-wire slicing in the presence of a cutting agent;
- (b) etching of the sliced wafers with an alkaline etchant in an etching bath at a temperature of 20° C. to 50° C. and for a residence time, such that a material removed from each of the sliced wafers is less than 5/1000 of an initial wafer thickness;
- and
- (c) grinding of the etched wafers by simultaneous double-disk grinding using an annular abrasive covering.
Dependencies are inferred from the claim text.