EP0811665A2
Expired / Lapsed
EP
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Chemical mechanical polishing slurry for metal layers and films
Assignee: CMC Materials LLC
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Filing: 1997-05-08
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Granted: —
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Expires: 2017-05-08
Abstract
Abstract A polishing slurry for chemically mechanically polishing metal layers and films during the various stages of multilevel interconnect fabrication associated with integrated circuit manufacturing. The slurry includes an aqueous medium, an abrasive, an oxidizing agent, and an organic acid. The polishing slurry has been found to significantly lower or inhibit the silicon dioxide polishing rate, thus yielding enhanced selectivity. In addition, the polishing slurry is useful in providing effective polishing to metal layers at desired polishing rates while minimizing surface imperfections and defects. Also disclosed is a method for producing coplanar metal/insulator films on a substrate utilizing the slurry of the present invention and chemical mechanical polishing technique relating thereto.
Inventors
- 👤 Debra L. Scherber
- 👤 Vlasta Brusic Kaufman
- 👤 Rodney C. Kistler
- 👤 Brian L. Mueller
- 👤 Christopher C. Streinz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 21:01
CPC Classifications
C; C09; C09G; C09G1/00; C09G1/02; C09K; C09K3/00; C09K3/14; C09K3/1454; C09K3/1463; C23; C23F; C23F3/00; H; H10; H10P; H10P52/00; H10P52/40; H10P52/403
Claims Analysis
Total Claims: 59
Claim 1
Independent Claim
52 words
A chemical-mechanical polishing slurry for polishing a substrate containing an insulator layer and at least one metal layer or thin-film comprising: an aqueous medium; an abrasive; an oxidizing agent; and an organic acid, wherein the selectivity between said metal layer or thin-film and said insulator layer is equal or greater than 50:1.
Claim 2
Dependent Claim
12 words
The slurry of claim 1, wherein said aqueous medium is deionized water.
Claim 3
Dependent Claim
12 words
The slurry of claim 1, wherein said aqueous medium is distilled water.
Claim 4
Dependent Claim
13 words
The slurry of claim 1, wherein said abrasive is a metal oxide abrasive.
Claim 5
Dependent Claim
26 words
The slurry of claim 4, wherein said metal oxide abrasive is selected from the group consisting of: alumina, ceria, germania, silica, titania, zirconia, and mixtures thereof.
Claim 6
Dependent Claim
33 words
The slurry of claim 4, wherein said metal oxide abrasive consists of metal oxides aggregates having a size distribution less than about 1.0 micron, a mean aggregate diameter less than about 0.4 micron.
Claim 7
Dependent Claim
42 words
The slurry of claim 4, wherein said metal oxide abrasive consists of discrete, individual metal oxide spheres having a primary particle diameter less than 0.400 micron and a surface area ranging from about 10 m 2 /g to about 250m 2 /g.
Claim 8
Dependent Claim
25 words
The slurry of claim 1, wherein said abrasive has a surface area ranging from about 5 m 2 /g to about 430 m 2 /g.
Claim 9
Dependent Claim
25 words
The slurry of claim 8, wherein said abrasive has a surface area ranging from about 30 m 2 /g to about 170 m 2 /g.
Claim 10
Dependent Claim
25 words
The slurry of claim 1, wherein said abrasive is present in said slurry in a range between about 0.5 % and 55 % by weight.
Claim 11
Dependent Claim
23 words
The slurry of claim 10, wherein said abrasive is present in said slurry in a range between about 1% and 10% by weight.
Claim 12
Dependent Claim
18 words
The slurry of claim 4, wherein said metal oxide abrasive is a precipitated abrasive or a fumed abrasive.
Claim 13
Dependent Claim
16 words
The slurry of claim 5, wherein said alumina is a precipitated alumina or a fumed alumina.
Claim 14
Dependent Claim
14 words
The slurry of claim 1, wherein said oxidizing agent is an oxidizing metal salt.
Claim 15
Dependent Claim
14 words
The slurry of claim 1, wherein said oxidizing agent is an oxidizing metal complex.
Claim 16
Dependent Claim
14 words
The slurry of claim 1, wherein said oxidizing agent is an oxidizing nonmetallic compound.
Claim 17
Dependent Claim
22 words
The slurry of claim 16, wherein said oxidizing nonmetallic compound is ammonium persulfate, hydrogen peroxide, peracetic acid, periodic acid and mixtures thereof.
Claim 18
Dependent Claim
40 words
The slurry of claim 1, wherein said oxidizing agent is selected from the group consisting of: iron salts, aluminum salts, sodium salts, potassium salts, ammonium salts, quaternary ammonium salts, phosphonium salts, peroxides, chlorates, perchlorates, nitrates, permanganates, persulfates and mixtures thereof.
Claim 19
Dependent Claim
32 words
The slurry of claim 1, wherein said organic acid is selected from the group consisting of: monofunctional acids, di-functional acids, hydroxyl acids, carboxylate acids, chelating acids and non-chelating acids, and mixtures thereof.
Claim 20
Dependent Claim
71 words
The slurry of claim 1, wherein said organic acid is selected from the group consisting of: acetic acid, adipic acid, butyric acid, capric acid, caproic acid, caprylic acid, citric acid, glutaric acid, glycolic acid, formic acid, fumaric acid, lactic acid, lauric acid, malic acid, maleic acid, malonic acid, myristic acid, oxalic acid, palmitic acid, phthalic acid, propionic acid, pyruvic acid, stearic acid, succinic acid, tartaric acid, valeric acid and derivatives thereof.
Claim 21
Dependent Claim
26 words
The slurry of claim 1, wherein said organic acid is present in said slurry in an amount sufficient to improve the oxide selectivity of said slurry.
Claim 22
Dependent Claim
21 words
The slurry of claim 21, wherein said organic acid is present in an amount between 0.5% and about 7% by weight.
Claim 23
Dependent Claim
12 words
The slurry of claim 1, wherein said slurry further comprises a surfactant.
Claim 24
Dependent Claim
26 words
The slurry of claim 23, wherein said surfactant is selected from the group consisting of: anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, and mixtures thereof.
Claim 25
Dependent Claim
13 words
The slurry of claim 1, wherein said slurry further comprises an inorganic acid.
Claim 26
Dependent Claim
13 words
The slurry of claim 1, wherein said slurry further comprises an inorganic salt.
Claim 27
Independent Claim
83 words
A method for chemical-mechanical polishing of a substrate containing an insulator layer and at least one metal layer or thin-film, the method which comprises the steps of: a) providing a chemical mechanical polishing slurry comprising: an aqueous medium, an abrasive, an oxidizing agent, and an organic acid, wherein the selectivity between said metal layer or thin-film and said insulator layer is equal or greater than 50:1; and b) chemical mechanical polishing a metal layer or thin-film on a semiconductor substrate with said slurry.
Claim 28
Dependent Claim
25 words
The method of claim 27, wherein said metal layer or thin-film is selected from the group consisting of: aluminum, copper, titanium, tantalum, and alloys thereof.
Claim 29
Dependent Claim
16 words
The method of claim 28, wherein said metal layer or thin-film is aluminum or aluminum alloy.
Claim 30
Dependent Claim
32 words
The method of claim 29, wherein said aluminum layer or thin-film further comprises at least one underlayer selected from the group consisting of titanium, titanium nitride, titanium tungsten, tantalum, and mixtures thereof.
Claim 31
Dependent Claim
12 words
The method of claim 28, wherein said metal-layer or thin-film is copper.
Claim 32
Dependent Claim
32 words
The method of claim 31, wherein said copper layer or thin-film further comprises at least one underlayer selected from the group consisting of: titanium, titanium nitride, titanium tungsten, tantalum, and mixtures thereof.
Claim 33
Dependent Claim
12 words
The method of claim 27, wherein said aqueous medium is deionized water.
Claim 34
Dependent Claim
12 words
The method of claim 27, wherein said aqueous medium is distilled water.
Claim 35
Dependent Claim
13 words
The method of claim 27, wherein said abrasive is a metal oxide abrasive.
Claim 36
Dependent Claim
26 words
The method of claim 35, wherein said metal oxide abrasive is selected from the group consisting of: alumina, ceria, germania, titania, silica, zirconia, and mixtures thereof.
Claim 37
Dependent Claim
33 words
The method of claim 35, wherein said metal oxide abrasive consists of metal oxides aggregates having a size distribution less than about 1.0 micron, a mean aggregate diameter less than about 0.4 micron.
Claim 38
Dependent Claim
43 words
The method of claim 35, wherein said metal oxide abrasive consists of discrete, individual metal oxide spheres having a primary particle diameter less than 0.400 micron and corresponding surface area ranging from about 10 m 2 /g to about 250 m 2 /g.
Claim 39
Dependent Claim
25 words
The method of claim 27, wherein said abrasive has a surface area ranging from about 5 m 2 /g to about 430 m 2 /g.
Claim 40
Dependent Claim
25 words
The method of claim 39, wherein said abrasive has a surface area ranging from about 30 m 2 /g to about 170 m 2 /g.
Claim 41
Dependent Claim
25 words
The method of claim 27, wherein said abrasive is present in said slurry in a range between about 0.5 % and 55 % by weight.
Claim 42
Dependent Claim
23 words
The method of claim 41, wherein said abrasive is present in said slurry in a range between about 1% and 10% by weight.
Claim 43
Dependent Claim
18 words
The method of claim 35, wherein said metal oxide abrasive is a precipitated abrasive or a fumed abrasive.
Claim 44
Independent Claim
15 words
The method of 36, wherein said alumina is a precipitated alumina or a fumed alumina.
Claim 45
Dependent Claim
14 words
The method of claim 27, wherein said oxidizing agent is an oxidizing metal salt.
Claim 46
Dependent Claim
14 words
The method of claim 27, wherein said oxidizing agent is an oxidizing metal complex.
Claim 47
Dependent Claim
14 words
The method of claim 27, wherein said oxidizing agent is an oxidizing nonmetallic complex.
Claim 48
Dependent Claim
23 words
The method slurry of claim 47, wherein said oxidizing nonmetallic complex is ammonium persulfate, hydrogen peroxide, peracetic acid, periodic acid and mixtures thereof.
Claim 49
Dependent Claim
40 words
The method of claim 27, wherein said oxidizing agent is selected from the group consisting of: iron salts, aluminum salts, sodium salts, potassium salts, ammonium salts, quaternary ammonium salts, phosphonium salts, peroxides, chlorates, perchlorates, nitrates, permanganates, persulfates and mixtures thereof.
Claim 50
Dependent Claim
32 words
The method of claim 27, wherein said organic acid is selected from the group consisting of: monofunctional acids, di-functional acids, hydroxyl acids, carboxylate acids, chelating acids and non-chelating acids, and mixtures thereof.
Claim 51
Dependent Claim
71 words
The method of claim 50, wherein said organic acid is selected from the group consisting of: acetic acid, adipic acid, butyric acid, capric acid, caproic acid, caprylic acid, citric acid, glutaric acid, glycolic acid, formic acid, fumaric acid, lactic acid, lauric acid, malic acid, maleic acid, malonic acid, myristic acid, oxalic acid, palmitic acid, phthalic acid, propionic acid, pyruvic acid, stearic acid, succinic acid, tartaric acid, valeric acid and derivatives thereof.
Claim 52
Dependent Claim
26 words
The method of claim 27, wherein said organic acid is present in said slurry in an amount sufficient to improve the oxide selectivity of said slurry.
Claim 53
Dependent Claim
21 words
The method of claim 52, wherein said organic acid is present in an amount between 0.5% and about 7% by weight.
Claim 54
Dependent Claim
12 words
The method of claim 27, wherein said slurry further comprises a surfactant.
Claim 55
Dependent Claim
26 words
The method of claim 54, wherein said surfactant is selected from the group consisting of: anionic surfactants, cationic surfactant, nonionic surfactants, amphoteric surfactants, and mixtures thereof.
Claim 56
Dependent Claim
13 words
The method of claim 27, wherein said slurry further comprises an inorganic acid.
Claim 57
Dependent Claim
13 words
The method of claim 27, wherein said slurry further comprises an inorganic salt.
Claim 58
Dependent Claim
23 words
The method of claim 30, wherein the selectivity between said aluminum layer or thin-film and said underlayer is equal or less than 10:1.
Claim 59
Dependent Claim
23 words
The method of claim 32, wherein the selectivity between said copper layer or thin-film and said underlayer is equal or less than 10:1.
References Cited (Backward Citations)
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