TiN hard mask and etch residual removal
Composition, method and system for PVD TiN hard mask removal from 28/20 nm pattern wafers have been disclosed. The composition uses peroxide as oxidizing agent for PVD TiN hard mask removal under slightly basic conditions. The composition comprises bulky or long chain organic amines or polyalkylamine to improve removal/etching selectivity of PVD TiN vs CVD TiN. The composition further comprises long chain organic acids or amines to maintain Co compatibility.
1. A composition for selectively removing PVD titanium nitride (TiN or TiNxOy; where x=0 to 1.3 and y=0 to 2) from a semiconductor device comprising the PVD titanium nitride and a second material selected from the group consisting of Cu, Co, CVD titanium nitride, dielectric material, low-k dielectric material, and combinations thereof, the composition comprising:
1 to 20 wt % peroxide,
1-5 wt % base,
0.1-1 wt % weak acid,
0.5 to 2 wt % ammonium salt,
25 to 5000 ppm corrosion inhibitor or 1-15 wt % of a long chain or mixed alkyammonium hydroxide,
10 to 5000 ppm, long chain organic amine or polyalkylamine,
and
solvent,
wherein
the ammonium salt is selected from the group consisting of ammonium citrate, ammonium acetate, ammonium malonate, ammonium adipate, ammonium lactate, ammonium iminodiacetate, ammonium chloride, ammonium bromide, ammonium fluoride, ammonium bifluoride, ammonium sulfate, and combinations thereof; and
the composition has a pH ranging from 7 to 11.5.
2. The composition of claim 1 , wherein the peroxide is selected from the group consisting of hydrogen peroxide, ammonium persulfate, peracidic acid, peroxybenzoic acid, and combinations thereof.
3. The composition of claim 2 , wherein the peroxide is hydrogen peroxide.
4. The composition of claim 1 , wherein the base is selected from the group consisting of tetraethylammonium hydroxide(TEAH), trimethylphenylammonium hydroxide, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, choline hydroxide, ammonium hydroxide, and combinations thereof.
5. The composition of claim 4 , wherein the base is tetraethylammonium hydroxide.
6. The composition of claim 1 , wherein the weak acid is carboxylic acid selected from the group consisting of citric acid, oxalic acid, malonic acid, lactic acid, adipic acid, acetic acid, iminodiacetic acid, and combinations thereof.
7. The composition of claim 6 , wherein the weak acid is citric acid.
8. The composition of claim 1 , wherein the ammonium salt is ammonium citrate.
9. The composition of claim 1 , wherein the corrosion inhibitor is selected from the group consisting of 1,2,4-triazole, benzotriazole, methyl-1H-benzotriazole, 2-aminobenthothiazole, benzimidazole, 2-mercapto-5-methylbenzimidaole, 8-hydroxyquinoline, 1-thioglycerol, ascorbic acid, pyrazole, and combinations thereof.
10. The composition of claim 9 , wherein the corrosion inhibitor is methyl-1H-benzotriazole.
11. The composition of claim 1 , wherein the long chain or mixed alkyammonium hydroxide is selected from the group consisting of trimethylphenylammonium hydroxide(TMPAH), choline hydroxide, tetrabutylammonium hydroxide and mixed tetraalkylammonium hydroxide, wherein the alkylammonium cation contains alkyl groups of at least two different chain lengths.
12. The composition of claim 11 , wherein the long chain or mixed alkyammonium hydroxide is trimethylphenylammonium hydroxide(TMPAH).
13. The composition of claim 1 , wherein the long chain organic amine or polyalkylamine is selected from the group consisting of hexylamine, surfactant salts of hexylamine, octylamine, surfactant salts of octylamine, dicyclohexylamine, surfactant salts of dicyclohexylamine, polyethyleneimine, surfactant salts of polyethyleneimine, decylamine, surfactant salts of decylamine, dodecylamine, surfactant salts of dodecylamine, and combinations thereof.
14. The composition of claim 1 , wherein the long chain organic amine or polyalkylamine is octylamine or polyethyleneimine.
15. The composition of claim 1 , wherein the solvent is selected from the group consisting of deionized water (DI water), purified water, distilled water, dimethyl sulfoxide(DMSO), dimethyl sulfone (DMSO 2 ), sulfolane ((CH 2 ) 4 SO 2 ), n-methylpyrrolidone, dipropyleneglycolmethylether, tripropyleneglycolmethyl ether, and combinations thereof.
16. The composition of claim 15 , wherein the solvent is water.
17. The composition of claim 1 further comprises from 0.01 to 1 wt % of a chelating agent selected from the group consisting of glycine, iminodiacetic acid, nitrilotriacetic acid, glutamic acid, picolinic acid, ethylenediamine tetraacetic acid(EDTA), and combinations thereof.
18. The composition of claim 1 further comprises from 100 ppm to 1000 ppm radical scavengers selected from the group consisting of manitol, polyalkylamines, (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl(TEMPO), diphenylamines, and combinations thereof.
19. The composition of claim 1 further comprises from 10 to 5000 ppm of long chain organic acids or amines.
20. The composition of claim 19 , wherein the long chain organic acid or amine is selected from the group consisting of decanonic acid, dodecanoic acid, dimer acid, hexylamine, surfactant salts of hexylamine, octylamine, surfactant salts of octylamine, dicyclohexylamine, surfactant salts of dicyclohexylamine, decylamine, surfactant salts of decylamine, dodecylamine, surfactant salt of dodecylamine, and combinations thereof.
21. The composition of claim 20 , wherein the long chain organic acid or amine is decanonic acid.
22. The composition of claim 1 , wherein the composition comprises hydrogen peroxide, tetraethylammonium hydroxide, citric acid, ammonium citrate, methyl-1H-benzotriazole or trimethylphenylammonium hydroxide (TMPAH), polyethyleneimine or octylamine, and water.
23. The composition of claim 1 wherein the peroxide is present at from about 3 wt % to about 15 wt %.
24. The composition of claim 1 wherein the pH ranges from 8 to 10.5.
25. The composition of claim 24 wherein the pH ranges from from 8.5 to 9.5.
26. The composition of claim 1 wherein the composition exhibits a removal selectivity of PVD titanium nitride vs. CVD titanium nitride >2, when the second material is CVD titanium nitride.
27. The composition of claim 1 wherein the peroxide is present from 1 to 9 wt %.
28. The composition of claim 23 wherein the peroxide is present at about 15 wt %.
29. A system for selectively removing PVD titanium nitride (TiN or TiNxOy, where x=0 to 1.3 and y=0 to 2) from a surface of a microelectronic device, comprising:
the semiconductor device comprising the PVD titanium nitride and a second material selected from Cu, Co, CVD titanium nitride dielectric material, low-k dielectric material and combinations thereof,
the composition of claim 1 for selectively removing the PVD titanium nitride, wherein the PVD titanium nitride and the second material are in direct contact with the composition the composition.
30. A process of selectively removing PVD titanium nitride (TiN or TiNxOy, where x=0 to 1.3 and y=0 to 2) comprising:
providing a semiconductor device comprising the PVD titanium nitride and a second material selected from Cu, Co, CVD titanium nitride dielectric material, low-k dielectric material;
contacting the semiconductor device with the composition of claim 1 ; and selectively removing the PVD titanium nitride,
wherein the PVD titanium nitride and the second material are in direct contact with the composition, and the composition offers a removal selectivity of PVD titanium nitride vs. CVD titanium nitride >2, when the second material is CVD titanium nitride.