Patent ID: 11970647
Assignee: BASF SE
Field: Semiconductors (Electrical engineering)
Classification: CPC C  H | IPC C  H

Claim 0:
1. A composition for selectively etching a layer comprising a silicon germanium alloy (SiGe) in the presence of a silicon-containing layer, the composition comprising:
(a) 0.01 to 3.0 mol/l of a peroxide,
(b1) 1% by weight or below of an inorganic acid having a pKa of 2 or less,
(b2) 10 to 60% by weight of an organic acid selected from a C1 to C10 mono, di or tri carboxylic acid, a C1 to C10 sulfonic acid, and a C1 to C10 phosphonic acid,
(c) 0.001 to 3 mol/l of an etchant selected from the group consisting of hydrogen fluoride, ammonium fluoride, ammonium bifluoride, triethanolammonium fluoride, diglycolammonium fluoride, methyldiethanolammonium fluoride, tetramethylammonium fluoride, triethylamine tri-hydrofluoride, fluoroboric acid, tetrafluoroboric acid, ammonium tetrafluoroborate, fluoroacetic acid, ammonium fluoroacetate, trifluoroacetic acid, fluorosilicic acid, ammonium fluorosilicate, tetrabutylammonium tetrafluoroborate, and mixtures thereof,
(d) 0.01 to 10% by weight of a polyvinylpyrrolidone (PVP), and
(e) water.