Siltronic Ag

Rudolf Lehner

Wolfgang Hensel

Helmut Schwenk

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 &#x3bc;m, an overall planarity value GBIR of 5 &#x3bc;m or less with an edge exclusion of 3 mm and a photolithographic resolution of at least 0.8 &#x3bc;m, and which furthermore contain a native oxide layer with a thickness of 0.5-3 nm on both sides.

Growing community of inventors

Trostberg, Germany

Rudolf Lehner