Etching Solution for Selectively Removing Silicon-Germanium Alloy From a Silicon-Germanium/ Germanium Stack During Manufacture of a Semiconductor Device

Patent metadata

Field	Value
Publication number	US-2019276739-A1
Application number	US-201916285961-A
Country	US
Kind code	A1
Filing date	Feb 26, 2019
Priority date	Mar 9, 2018
Publication date	Sep 12, 2019
Grant date	—

Abstract

Described herein is an etching solution comprising water; an oxidizer; a water-miscible organic solvent; a fluoride ion source; a corrosion inhibitor and optionally, a surfactant, optionally a buffer, optionally a chelating agent. Such compositions are useful for the selective removal of silicon-germanium over germanium from a microelectronic device having such material(s) thereon during its manufacture.

First claim

1 . An etching solution suitable for the selective removal of silicon-germanium alloy over germanium from a microelectronic device, which comprises:
water; an oxidizer; a water-miscible organic solvent; a fluoride ion source; a corrosion inhibitor; optionally a surfactant; optionally a buffer; and optionally a chelating agent.

2 . The etching solution of claim 1 wherein the oxidizer is a quinone.

3 . The etching solution of claim 1 wherein the oxidizer is selected from the group consisting of 1,4-Benzoquinone, 1,2-Benzoquinone, 1,4-Naphthoquinone, and 9,10-Anthraquinone.

4 . The etching solution of claim 1 wherein the composition is substantially free of peroxides.

5 . The etching composition of claim 1 wherein the water-miscible solvent is selected from the group consisting of ethylene glycol, propylene glycol, butyl diglycol, 1,4-butanediol, tripropylene glycol methyl ether, propylene glycol propyl ether, diethylene gycol n-butyl ether, hexyloxypropylamine, poly(oxyethylene)diamine, dimethylsulfoxide, tetrahydrofurfuryl alcohol, glycerol, alcohols, sulfoxides, dimethylacetamide, pyrrolidones, sulfur-containing solvents, or mixtures thereof.

6 . The etching composition of claim 1 wherein the water-miscible solvent is selected from the group consisting of sulfoxides, sulfolane, sulfolene, sulfone or mixtures thereof.

7 . The etching composition of claim 1 wherein the water-miscible solvent is selected from the group consisting of sulfolane, dimethylsulfoxide, n-methylpyrrilodone, polyethylene glycol and dimethylacetamide or mixtures thereof.

8 . The etching composition of claim 1 wherein the corrosion inhibitor is selected from the group consisting of catechol; (C1-C6) alkylcatechol, triazoles, imidazoles, gallic acid, gallic acid esters, cysteine, methylbis(1-dimethylaminoethyl)amine (polycat 5), 1-octylamine, quinoline, quinoline derivatives, cetyltrimethyl ammonium bromide (CTAB), 11-mercaptoundecanoic acid, and n-methyl-n-octylamine.

9 . The etching composition of claim 1 wherein the corrosion inhibitor is selected from the group consisting of methylcatechol, ethylcatechol and tert-butylcatechol, benzotriazole, (C1-C10) alkylbenzotriazoles, 1,2,3-triazoles, 1,2,4-triazole, benzotriazole, (C1-C10) alkylbenzotriazoles, benzotriazole-5-carboxylic acid, methyl gallate propyl gallate, hydroxy-substituted quinolines, 8-hydroxyquinoline, alkyl-substituted quinolines, 2-methyl quinoline and 4-methyl quinoline,

10 . The etching composition of claim 1 wherein the corrosion inhibitor is selected from the group consisting of 8-hydroxyquinoline, cetyltrimethyl ammonium bromide (CTAB), 1-mercaptoundecanoic acid and n-methyl-n-octylamine.

11 . The etching composition of claim 1 wherein the corrosion inhibitor comprises quinoline.

12 . The etching composition of claim 1 wherein the buffer is present in the composition.

13 . The etching composition of claim 12 wherein the buffer comprises citric acid and triammonium citrate.

14 . The etching composition of claim 12 , wherein the buffer composition comprises an amine compound and a polyfunctional organic acid.

15 . The etching composition of claim 14 , wherein the amine compound is an alkanolamine and the polyfunctional organic acid is a polyprotic acids having at least three carboxylic acid groups.

16 . The etching composition of claim 15 , wherein the polyprotic acid is selected from the group consisting of citric acid, 2-methylpropane-1,2,3-triscarboxylic, benzene-1,2,3-tricarboxylic [hemimellitic], propane-1,2,3-tricarboxylic [tricarballylic], 1,cis-2,3-propenetricarboxylic acid [aconitic], e.g., butane-1,2,3,4-tetracarboxylic, cyclopentanetetra-1,2,3,4-carboxylic, benzene-1,2,4,5-tetracarboxylic [pyromellitic], benzenepentacarboxylic, and benzenehexacarboxylic [mellitic]), and mixtures thereof.

17 . The etching composition of claim 1 wherein the fluoride ion source is selected from the group consisting of hydrofluoric acid, ammonium fluoride, quaternary ammonium fluorides such as, for example, fluoroborates, fluoroboric acid, tetrabutylammonium tetrafluoroborate, aluminum hexafluoride, and a fluoride salt of an aliphatic primary, secondary or tertiary amine having the formula:
R 1 NR 2 R 3 R 4 F,

wherein R 1 , R 2 , R 3 and R 4 individually represent H or a (C 1 -C 4 ) alkyl group.

18 . The etching composition of claim 17 wherein the fluoride ion source is selected from the group consisting of ammonium fluoride, ammonium bifluoride, tetramethylammonium fluoride, tetraethylammonium fluoride, methyltriethylammonium fluoride, and tetrabutylammonium fluoride.

19 . The etching composition of claim 17 wherein said fluoride ion source is ammonium fluoride.

20 . The etching composition of claim 1 wherein the composition comprises the chelating agent.

21 . The etching composition of claim 1 wherein the composition comprises the surfactant.

22 . A method of selectively enhancing the etch rate of silicon-germanium relative to germanium on a semiconductor device comprising germanium and silicon-germanium, the method comprising the steps of:
contacting the semiconductor device comprising silicon and silicon-germanium with an aqueous composition comprising: water; an oxidizer; a water-miscible organic solvent; a fluoride ion source and a corrosion inhibitor; and optionally, a surfactant; optionally a chelating agent and optionally a buffer; and rinsing the composite semiconductor device after the silicon-germanium is at least partially removed, wherein the selectivity of the etch for silicon-germanium over germanium is greater than about 2.

23 . The method of claim 22 further comprising the step of drying the semiconductor device.

24 . The method of claim 22 wherein the selectivity of the etch for silicon-germanium over germanium is greater than 2.5.

25 . The method of claim 22 wherein the contacting step is performed at a temperature of from about 25° C. to about60° C.

Assignees

• Versum Mat Us Llc

Inventors

• Liu Wen Dar
• Lee Yi-Chia

Classifications

• H10P70/20

  Cleaning during device manufacture · CPC title

• H10P50/642 Primary

  Chemical etching · CPC title

• C09K13/00 Primary

  Etching, surface-brightening or pickling compositions (for glass C03C15/00, {C03C25/66; for mortars, concrete, artificial or natural stone or ceramics C04B41/5338}; for metallic material C23F, C23G1/00, C25F1/00; {for semi-conductors H10P52/40}) · CPC title

• H10P50/667

  by liquid etching only · CPC title

• H01L21/02057

  Electricity · mapped topic