Stripping Compositions Having High WN/W Etching Selectivity

Patent metadata

Field	Value
Publication number	US-2016186105-A1
Application number	US-201514976737-A
Country	US
Kind code	A1
Filing date	Dec 21, 2015
Priority date	Dec 30, 2014
Publication date	Jun 30, 2016
Grant date	—

Abstract

A composition for cleaning integrated circuit substrates, the composition comprising: water; an oxidizer comprising an ammonium salt of an oxidizing species; a corrosion inhibitor comprising a primary alkylamine having the general formula: R′NH 2 , wherein R′ is an alkyl group containing up to about 150 carbon atoms and will more often be an aliphatic alkyl group containing from about 4 to about 30 carbon atoms; optionally, a water-miscible organic solvent; optionally, an organic acid; optionally, a buffer speicies; optionally, a fluoride ion source; and optionally, a metal chelating agent.

First claim

1 . A composition for cleaning integrated circuit substrates, the composition comprising:
a. water; b. an oxidizer comprising an ammonium salt of an oxidizing species; c. a corrosion inhibitor comprising a primary alkylamine having the general formula: R′NH 2 , wherein R′ is an alkyl group containing up to about 150 carbon atoms and will more often be an aliphatic alkyl group containing from about 4 to about 30 carbon atoms; d. optionally, a water-miscible organic solvent; e. optionally, an organic acid; f. optionally, a buffer speicies; g. optionally, a fluoride ion source; and h, optionally, a metal chelating agent.

2 . The composition of claim 1 having a pH of from 3.0 to 6.5.

3 . The composition of claim 1 wherein the ammonium salt of an oxidizing species is selected from the group consisting of ammonium chlorite (NH 4 ClO2), ammonium chlorate (NH 4 ClO 3 ), ammonium iodate (NH 4 lO 3 ), ammonium perborate (NH 4 BO 3 ), ammonium perchlorate (NH 4 ClO 4 ), ammonium periodate (NH 4 lO 3 ), ammonium persulfate ((NH 4 ) 2 S 2 O 8 ), tetramethylammonium chlorite ((N(CH 3 ) 4 )ClO 2 ), tetramethylammonium chlorate ((N(CH 3 ) 4 )ClO 3 ), tetramethylammonium iodate ((N(CH 3 ) 4 lO 3 ), tetramethylammonium perborate ((N(CH 3 ) 4 )BO 3 ), tetramethylammonium perchlorate ((N(CH 3 ) 4 )ClO 4 ), tetramethylammonium periodate ((N(CH 3 ) 4 )lO 4 ), tetramethylammonium persulfate ((N(CH 3 ) 4 )S 2 O 8 ), and combinations thereof.

4 . The composition of claim 3 wherein the ammonium salt of an oxidizing species is ammonium persulfate,

5 . The composition of claim 1 wherein the buffer species is present and comprises a tetralkylammonium salt of a weak acid, wherein the tetralkylammonium salt comprises a tetralkylammonium cation represented by [NR 1 R 2 R 3 R 4 ] + , where R 1 , R 2 , R 3 and R 4 may be the same as or different from one another and are selected from the group consisting of C 1 -C 6 straight-chained or branched alkyl or C 6 -C 10 substituted or unsubstituted aryl groups, and
the weak acid is selected from the group consisiting of boric acid, lactic acid, maleic acid, ascorbic acid, malic acid, benzoic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, mandelic acid, maleic anhydride, acetic, propionic, citric acid, phthalic acid, an aromatic carboxylic acid, and combinations thereof.

6 . The composition of claim 5 whereint the buffer species is a tetramethylammonium salt of citric acid or a tetramethylammonium salt of boric acid.

7 . The composition of claim 1 wherein the corrosion inhibitor is selected from the group consisting of n-hexylamine, n-octylarnine, n-decylamine, n-dodecylamine, n-tetradecylamine, n-pentadecylamine, n-hexadecylamine, and n-octadecylamine (stearyl amine).

8 . The composition of claim 7 wherein the corrosion inhibitor is n-octylamine.

9 . The composition of claim 1 wherein the corrosion inhibitor is selected from the group consisting of ,3′-lminobis(N,N-dimethylpropylamine), Bis(3-aminopropyl)amine, Pentamethyldiethylenetriamine (PMDETA), and Polyethylenimine (PEI).

10 . The composition of claim 9 wherein the corrosion inhibitor is Polyethylenimine.

11 . The composition of claim 1 wherein the water-miscible organic solvent is present and is selected from the group consisting of ethylene glycol, propylene glycol, 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, and mixtures thereof.

12 . The composition of claim 11 wherein the water-miscible organic solvent is a diol.

13 . The composition of claim 1 wherein the metal chelating agent is present and is selected from the group consisting of (ethylenedinitrilo)tetraacetic acid (EDTA), butylenediaminetetraacetic acid, (1,2-cyclohexylenedinitrilo-)tetraacetic acid (CyDTA), diethylenetriaminepentaacetic acid (DETPA), ethylenediaminetetrapropionic acid, (hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), N, N,N′, N′-ethylenediaminetetra(methylenephosphonic) acid (EDTMP), triethylenetetraminehexaacetic acid (TTHA), 1,3-diamino-2-hydroxypropane-N,N,N′,N′-tetraacetic acid (DHPTA), methyliminodiacetic acid, propylenediaminetetraacetic acid, nitrolotriacetic acid (NTA), citric acid, tartaric acid, gluconic acid, saccharic acid, glyceric acid, oxalic acid, phthalic acid, maleic acid, mandelic acid, malonic acid, lactic acid, salicylic acid, catechol. gallic acid, propyl gallate, pyrogallol, 8-hydroxyquinoline, and cysteine.

14 . The composition of claim 13 wherein the metal chelating agent is selected from the group consisting of EDTA, CyDTA, and EDTMP.

15 . The composition of claim 1 wherein the a fluoride ion source is present and is selected from the group consisting of hydrofluoric acid and/or salts thereof, ammonium fluoride, tetramethylammonium fluoride, tetrabutylammonium fluoride, fluoroborates, fluoroboric acid, tetrabutylammonium tetrafluoroborate, and aluminum hexafluoride.

16 . A composition for cleaning integrated circuit substrates, the composition consisting of:
from about 12 to about 25% by wt. of water; from about 0.50 to about 2.0% by wt. of an oxidizer comprising an ammonium salt of an oxidizing species; from about 0.01 to about 3.0% by wt. of a corrosion inhibitor comprising a primary alkylamine having the general formula: R′NH 2 , wherein R′ is an alkyl group containing up to about 150 carbon atoms and will more often be an aliphatic alkyl group containing from about 4 to about 30 carbon atoms; from about 5 to about 60% by wt. of a water-miscible organic solvent; from about 0.2 to about 10% by weight of a buffer species; and from about 0.1 to about 3% by wt. of a fluoride ion source.

17 . The composition of claim 16 having a pH of from 3.0 to 6.5.

18 . The composition of claim 16 wherein the ammonium salt of an oxidizing species is selected from the group consisting of ammonium chlorite (NH 4 ClO 2 ), ammonium chlorate (NH 4 ClO 3 ), ammonium iodate (NH 4 lO 3 ), ammonium perborate (NH 4 BO 3 ), ammonium perchlorate (NH 4 ClO 4 ), ammonium periodate (NH 4 lO 3 ), ammonium persulfate ((NH 4 ) 2 S 2 O 8 ), tetramethylammonium chlorite ((N(CH 3 ) 4 )ClO 2 ), tetramethylammonium chlorate ((N(CH 3 ) 4 )ClO 3 ), tetramethylammonium iodate ((N(CH 3 ) 4 lO 3 ), tetramethylammonium perborate ((N(CH 3 ) 4 )BO 3 ), tetramethylammonium perchlorate ((N(CH 3 ) 4 )ClO 4 ), tetramethylammonium periodate ((N(CH 3 ) 4 )lO 4 ), tetramethylammonium persulfate ((N(CH 3 ) 4 )S 2 O 8 ), and combinations thereof.

19 . The composition of claim 18 wherein the ammonium salt of an oxidizing species is ammonium persulfate.

20 . The composition of claim 16 wherein the buffer species comprises a tetralkylammonium salt of a weak acid, wherein the tetralkylammonium salt comprises a tetralkylammonium cation represented by [NR 1 R 2 R 3 R 4 ] + , where R 1 , R 2 , R 3 and R 4 may be the same as or different from one another and are selected from the group consisting of C 1 -C 6 straight-chained or branched alkyl or C 6 -C 10 substituted or unsubstituted aryl groups, and the weak acid is selected from the group consisiting of boric acid, lactic acid, maleic acid, ascorbic acid, malic acid, benzoic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, mandelic acid, maleic anhydride, acetic, propionic, citric acid, phthalic acid, an aromatic carboxylic acid, and combinations thereof.

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Assignees

• Air Prod & Chem

Inventors

• Liu Wen Dar
• Lee Yi-Chia
• Chen Tianniu
• Casteel Jr William Jack
• Inaoka Seiji
• Parris Gene Everad

Classifications

• H10P70/234

  the processing being the formation of vias or contact holes · CPC title

• H10P50/667

  by liquid etching only · CPC title

• H10P50/73

  using masks for insulating materials · CPC title

• C11D7/08

  Acids · CPC title

• C11D7/265

  Carboxylic acids or salts thereof · CPC title