US4479852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for determination of concentration of organic additive in plating bath
Assignee: International Business Machines Corp
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Filing: 1983-01-21
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Granted: 1984-10-30
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Expires: 2003-01-21
Abstract
Abstract The concentration of an organic additive in a plating bath is determined by providing a polished and constant current density preplated rotating disc cathode, a reference electrode and anode in an electrolytic copper plating bath, passing an electric current from the anode to the cathode and reference electrode; measuring the voltage difference between the cathode and reference electrode; and comparing the difference to values for known concentrations of the organic additive.
Inventors
- 👤 Perminder S. Bindra
- 👤 Allan P. David
- 👤 Raymond T. Galasco
- 👤 David N. Light
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:38
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/4161
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
132 words
A method of determining the concentration of at least one organic additive in an acidic electrolytic copper plating bath comprising the steps of: (a) preparing a cathode by electroplating a copper film onto a substrate by immersing the substrate in a copper plating bath and preplating copper thereon at a constant current density and constant voltage; said cathode being a rotating disk electrode; (b) providing in an acidic electrolytic copper plating bath, said cathode from step (a), a reference electrode, and an anode; (c) passing an electric current at a constant current density from said anode to said cathode; (d) measuring the voltage difference between said cathode and said reference electrode; and (e) comparing the measured voltage difference from step (d) with previous measured values for known concentrations of said organic additive.
Claim 2
Independent Claim
132 words
A method of determining the concentration of at least one organic additive in an acidic electrolytic copper plating bath comprising the steps of: (a) preparing a cathode by electroplating a copper film onto a substrate by immersing the substrate in a copper plating bath and preplating copper thereon at a constant current density and constant voltage; said cathode being a rotating disk electrode; (b) providing in an acidic electrolytic copper plating bath, said cathode from step (a), a reference electrode, and an anode; (c) passing an electric current at a constant current density from said anode to said cathode; (d) measuring the voltage difference between said cathode and said reference electrode; and (e) comparing the measured voltage difference from step (d) with previous measured values for known concentrations of said organic additive.
Claim 3
Dependent Claim
27 words
The method of claim 1 whereby the smoothness of the coating from the preplating is the same as that of the copper plated during the measuring step.
Claim 4
Dependent Claim
21 words
The method of claim 1 wherein the thickness of the copper from the preplating is about 0.5 to about 1.5 microns.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein the preplating is carried out for about 3 to about 7 minutes.
Claim 6
Dependent Claim
30 words
The method of claim 1 wherein the preplating and plating are carried out at a substantially constant current density of about 1 mA/cm 2 to about 12 mA/cm 2 .
Claim 7
Dependent Claim
30 words
The method of claim 1 wherein the preplating and plating are carried out at a substantially constant current density of about 8 mA/cm 2 to about 12 mA/cm 2 .
Claim 8
Dependent Claim
15 words
The method of claim 1 wherein said organic additive contains at least one polyalkylene glycol.
Claim 9
Dependent Claim
15 words
The method of claim 7 wherein said polyalkylene glycol is polyethylene glycol or polypropylene glycol.
Claim 10
Dependent Claim
12 words
The method of claim 7 wherein said polyalkylene glycol is polyethylene glycol.
Claim 11
Dependent Claim
19 words
The method of claim 1 wherein said plating bath contains a source of cupric ions and an inorganic acid.
Claim 12
Dependent Claim
13 words
The method of claim 10 wherein said plating bath contains Cl - ions.
Claim 13
Dependent Claim
30 words
The method of claim 10 wherein said bath contains about 0.1 to 0.3 M of said source of cupric ions and about 1.5 to about 2.5 M of said acid.
Claim 14
Dependent Claim
35 words
The method of claim 12 wherein said source of copper is CuSO 4 , and said acid is H 2 SO 4 , the amount of said Cl - is about 30 to 70 ppm.
Claim 15
Dependent Claim
25 words
The method of claim 13 further includes maintaining the amount of organic additive with a predetermined value of about 0.5 to about 1.25% by volume.
Claim 16
Independent Claim
12 words
The method of claim wherein said value is about 1% by volume.
Claim 17
Dependent Claim
39 words
The method of claim 15 wherein the amount of said CuSO 4 is about 0.267 M, the amount of said H 2 SO 4 is about 1.67 M, and the amount of said Cl - is about 50 ppm.
Claim 18
Dependent Claim
22 words
The method of claim 10 wherein said source of copper is CuSO 4 and said acid is H 2 S 4 .
Claim 19
Dependent Claim
14 words
The method of claim 1 wherein said cathode is polished prior to the preplating.
Claim 20
Dependent Claim
16 words
The method of claim 1 wherein the plating bath is diluted with water for enhanced sensitivity.
Claim 21
Dependent Claim
15 words
The method of claim 19 wherein the plating bath is diluted to 40% with water.
Claim 22
Dependent Claim
12 words
The method of claim 1 wherein said cathode is a noble metal.
Claim 23
Dependent Claim
10 words
The method of claim 1 wherein said cathode is gold.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-30 | 1988-04-30 | 1988-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-30 | 1992-04-30 | 1992-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-30 | 1996-04-30 | 1996-10-30 | $7700.00 | Window Closed / Lapsed |