	US 11,970,647 B2
	Composition, its use and a process for selectively etching silicon-germanium material
Francisco Javier Lopez Villanueva, Ludwigshafen (DE); Yeni Burk, Ludwigshafen (DE); Daniel Loeffler, Ludwigshafen (DE); Jan Ole Mueller, Ludwigshafen (DE); Marcel Brill, Ludwigshafen (DE); Patrick Wilke, Ludwigshafen (DE); Jean-Pierre Berkan Lindner, Ludwigshafen (DE); and Volodymyr Boyko, Ludwigshafen (DE)
Assigned to BASF SE, Ludwigshafen am Rhein (DE)
Appl. No. 17/624,872
Filed by BASF SE, Ludwigshafen am Rhein (DE)
PCT Filed Jun. 19, 2020, PCT No. PCT/EP2020/067146 § 371(c)(1), (2) Date Jan. 5, 2022, PCT Pub. No. WO2021/004759, PCT Pub. Date Jan. 14, 2021.
Claims priority of application No. 19184952 (EP), filed on Jul. 8, 2019.
Prior Publication US 2022/0290050 A1, Sep. 15, 2022
Int. Cl. C09K 13/08 (2006.01); C09K 13/00 (2006.01); H01L 21/306 (2006.01); H01L 21/311 (2006.01); H01L 21/3213 (2006.01)

CPC C09K 13/08 (2013.01) [C09K 13/00 (2013.01); H01L 21/30604 (2013.01); H01L 21/31111 (2013.01); H01L 21/32134 (2013.01)]

18 Claims

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 pK_aof 2 or less,

(b2) 10 to 60% by weight of an organic acid selected from a C₁to C₁₀mono, di or tri carboxylic acid, a C₁to C₁₀sulfonic acid, and a C₁to C₁₀phosphonic 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.