US6290833B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for electrolytically depositing copper on a semiconductor workpiece
Assignee: Applied Materials Inc
•
Filing: 1999-08-31
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Granted: 2001-09-18
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Expires: 2019-08-31
Abstract
Abstract This invention employs a novel approach to the copper metallization of a workpiece, such as a semiconductor workpiece. In accordance with the invention, an alkaline electrolytic copper bath is used to electroplate copper onto a seed layer, electroplate copper directly onto a barrier layer material, or enhance an ultra-thin copper seed layer which has been deposited on the barrier layer using a deposition process such as PVD. The resulting copper layer provides an excellent conformal copper coating that fills trenches, vias, and other microstructures in the workpiece. When used for seed layer enhancement, the resulting copper seed layer provide an excellent conformal copper coating that allows the microstructures to be filled with a copper layer having good uniformity using electrochemical deposition techniques. Further, copper layers that are electroplated in the disclosed manner exhibit low sheet resistance and are readily annealed at low temperatures.
Inventors
- 👤 LinLin Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:15
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/20; C; C25; C25D; C25D7/00; C25D7/12; C25D7/123; C23; C23C; C23C28/00; C23C28/30; C23C28/32; C23C28/322; C23C28/34; C25D3/00; C25D3/02; C25D3/38; C25D5/00; C25D5/10; C25D5/627; H10P14/40; H10P14/46; H10P14/47; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/033; H10W20/041; H10W20/042; H10W20/043; H10W20/056; H05; H05K; H05K3/00; H05K3/40; H05K3/42; H05K3/423; H10W20/0425
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
140 words
A process for applying a metal structure to a workpiece comprising: providing a first electroplating bath including copper sulfate as a source of metal ions as a principal metal species to be deposited during subsequent electroplating, ammonium sulfate, a complexing agent, and ethylene glycol; providing a workpiece on which one or more microelectronic devices are to be formed; exposing at least one surface of the workpiece to the first electroplating bath; providing electroplating power between the at least one surface of the workpiece and an anode disposed in electrical contact with the first electroplating bath to electroplate copper onto the at least one surface of the workpiece in an electrolytic first deposition process; and depositing additional copper onto the copper deposited in the first deposition process using a second deposition process that is different than the first electrolytic deposition process.
Claim 2
Dependent Claim
140 words
A process for applying a metal structure to a workpiece comprising: providing a first electroplating bath including copper sulfate as a source of metal ions as a principal metal species to be deposited during subsequent electroplating, ammonium sulfate, a complexing agent, and ethylene glycol; providing a workpiece on which one or more microelectronic devices are to be formed; exposing at least one surface of the workpiece to the first electroplating bath; providing electroplating power between the at least one surface of the workpiece and an anode disposed in electrical contact with the first electroplating bath to electroplate copper onto the at least one surface of the workpiece in an electrolytic first deposition process; and depositing additional copper onto the copper deposited in the first deposition process using a second deposition process that is different than the first electrolytic deposition process.
Claim 3
Dependent Claim
20 words
The process of claim 1 , wherein the copper sulfate is included at a level of 0.03 to 0.25 M.
Claim 4
Dependent Claim
15 words
The process of claim 1 , wherein the first electroplating bath comprises an alkaline bath.
Claim 5
Dependent Claim
17 words
The process of claim 3 , wherein the alkaline bath has a pH of at least 9.0.
Claim 6
Dependent Claim
32 words
The process of claim 3 , wherein the alkaline bath is pH adjusted with an alkaline agent selected from the group consisting of potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide and sodium hydroxide.
Claim 7
Dependent Claim
17 words
The process of claim 1 , wherein the second deposition process occurs in an acidic electrolytic bath.
Claim 8
Dependent Claim
25 words
The process of claim 1 , wherein metal is deposited in the second deposition process at a higher rate than in the first deposition process.
Claim 9
Dependent Claim
20 words
The process of claim 1 , wherein the ammonium sulfate is included at a level of 0.1 to 0.5 M.
Claim 10
Dependent Claim
23 words
The process of claim 1 , further comprising depositing a barrier layer on the surface of the workpiece before the first deposition process.
Claim 11
Dependent Claim
20 words
The process of claim 9 , wherein metal is plated directly onto the barrier layer in the first deposition process.
Claim 12
Dependent Claim
24 words
The process of claim 9 , further comprising depositing an ultra-thin seed layer of metal onto the barrier layer before the first deposition process.
Claim 13
Dependent Claim
23 words
The process of claim 1 , wherein the complexing agent is selected from the group consisting of ED, EDTA, and a polycarboxylic acid.
Claim 14
Dependent Claim
13 words
The process of claim 12 , wherein the complexing agent is citric acid.
Claim 15
Dependent Claim
147 words
A process for applying a metal structure to a workpiece comprising: providing a first electroplating bath including copper sulfate as a source of metal ions as a principal metal species to be deposited during subsequent electroplating, a complexing agent, and ethylene glycol; providing a workpiece on which one or more microelectronic devices are to be formed, exposing at least one surface of the workpiece to the first electroplating bath; providing electroplating power between the at least one surface of the workpiece and an anode disposed in electrical contact with the first electroplating bath to electroplate copper onto the at least one surface of the workpiece in an electrolytic first deposition process at a first deposition rate; and depositing additional copper onto the copper deposited in the first deposition process using a second deposition process at a second deposition rate that is higher than the first deposition rate.
Claim 16
Dependent Claim
147 words
A process for applying a metal structure to a workpiece comprising: providing a first electroplating bath including copper sulfate as a source of metal ions as a principal metal species to be deposited during subsequent electroplating, a complexing agent, and ethylene glycol; providing a workpiece on which one or more microelectronic devices are to be formed, exposing at least one surface of the workpiece to the first electroplating bath; providing electroplating power between the at least one surface of the workpiece and an anode disposed in electrical contact with the first electroplating bath to electroplate copper onto the at least one surface of the workpiece in an electrolytic first deposition process at a first deposition rate; and depositing additional copper onto the copper deposited in the first deposition process using a second deposition process at a second deposition rate that is higher than the first deposition rate.
Claim 17
Dependent Claim
185 words
A process for applying a metal structure to a workpiece comprising: providing a workpiece on which one or more microelectronic devices are to be formed; depositing a barrier layer on at least one surface of a workpiece; providing a first electroplating bath including copper sulfate as a source of principal metal species to be deposited during subsequent electroplating, ethylene glycol, a metal ion complexing agent, and an alkaline agent in an amount to adjust the pH of the first electroplating bath to a pH of at least 9.0; exposing the least one surface of the workpiece including the barrier layer to the first electroplating bath; providing electroplating power between the at least one surface of the workpiece and an anode disposed in electrical contact with the first electroplating bath to electroplate copper directly onto the barrier layer of the workpiece in an electrolytic first deposition process; and depositing additional copper onto the copper deposited in the first deposition process using a second deposition process at a second deposition rate that is higher than a rate at which copper is deposited in the first deposition process.
Claim 18
Dependent Claim
185 words
A process for applying a metal structure to a workpiece comprising: providing a workpiece on which one or more microelectronic devices are to be formed; depositing a barrier layer on at least one surface of a workpiece; providing a first electroplating bath including copper sulfate as a source of principal metal species to be deposited during subsequent electroplating, ethylene glycol, a metal ion complexing agent, and an alkaline agent in an amount to adjust the pH of the first electroplating bath to a pH of at least 9.0; exposing the least one surface of the workpiece including the barrier layer to the first electroplating bath; providing electroplating power between the at least one surface of the workpiece and an anode disposed in electrical contact with the first electroplating bath to electroplate copper directly onto the barrier layer of the workpiece in an electrolytic first deposition process; and depositing additional copper onto the copper deposited in the first deposition process using a second deposition process at a second deposition rate that is higher than a rate at which copper is deposited in the first deposition process.
Claim 19
Dependent Claim
25 words
The process of claim 15 , wherein the alkaline agent selected from the group consisting of potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide and sodium hydroxide.
Claim 20
Dependent Claim
17 words
The process of claim 15 , wherein the second deposition process occurs in an acidic electrolytic bath.
Claim 21
Dependent Claim
23 words
The process of claim 15 , wherein the complexing agent is selected from the group consisting of ED, EDTA, and a polycarboxylic acid.
Claim 22
Dependent Claim
13 words
The process of claim 18 , wherein the complexing agent is citric acid.
Claim 23
Dependent Claim
156 words
A process for applying a metal structure to a workpiece comprising: providing a first electroplating bath including copper sulfate as a source of metal ions as a principal metal species to be deposited during subsequent electroplating, a complexing agent, ethylene glycol, and an alkaline agent in an amount sufficient to raise the pH of the bath to at least 9.0; providing a workpiece on which one or more microelectronic devices are to be formed; exposing at least one surface of the workpiece to the first electroplating bath; providing electroplating power between the at least one surface of the workpiece and an anode disposed in electrical contact with the first electroplating bath to electroplate copper onto the at least one surface of the workpiece in an electrolytic first deposition process; and depositing additional copper onto the copper deposited in the first deposition process using a second deposition process that is different than the first electrolytic deposition process.
Claim 24
Dependent Claim
156 words
A process for applying a metal structure to a workpiece comprising: providing a first electroplating bath including copper sulfate as a source of metal ions as a principal metal species to be deposited during subsequent electroplating, a complexing agent, ethylene glycol, and an alkaline agent in an amount sufficient to raise the pH of the bath to at least 9.0; providing a workpiece on which one or more microelectronic devices are to be formed; exposing at least one surface of the workpiece to the first electroplating bath; providing electroplating power between the at least one surface of the workpiece and an anode disposed in electrical contact with the first electroplating bath to electroplate copper onto the at least one surface of the workpiece in an electrolytic first deposition process; and depositing additional copper onto the copper deposited in the first deposition process using a second deposition process that is different than the first electrolytic deposition process.
Claim 25
Dependent Claim
56 words
A copper electroplating solution comprising copper sulfate as a source of copper ions at a level so as to be the principal metal species, ammonium sulfate, and ethylene glycol at a levl of greater than 0 to 1.0 Molar, the solution being formulated so as to be suitable for electrodeposition of copper onto a microelectronic workpiece.
Claim 26
Dependent Claim
56 words
A copper electroplating solution comprising copper sulfate as a source of copper ions at a level so as to be the principal metal species, ammonium sulfate, and ethylene glycol at a levl of greater than 0 to 1.0 Molar, the solution being formulated so as to be suitable for electrodeposition of copper onto a microelectronic workpiece.
Claim 27
Dependent Claim
11 words
The solution of claim 21 , further comprising a complexing agent.
Claim 28
Dependent Claim
22 words
The solution of claim 22 wherein the complexing agent is selected from the group consisting of ED, EDTA, and a polycarboxylic acid.
Claim 29
Dependent Claim
12 words
The solution of claim 23 wherein the complexing agent is citric acid.
Claim 30
Dependent Claim
26 words
The solution of claim 21 , further comprising an alkaline agent in an amount sufficient to increase the pH of the solution to at least 9.0.
Claim 31
Dependent Claim
20 words
The solution of claim 21 , wherein the ammonium sulfate is included at the level of 0.1 to 0.5 M.
Claim 32
Dependent Claim
19 words
The solution of claim 21 , further comprising boric acid at a level of 0.01 Molar to 0.5 Molar.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2004-09-17 | 2005-03-19 | 2005-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-09-17 | 2009-03-19 | 2009-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-09-17 | 2013-03-19 | 2013-09-18 | $7700.00 | Window Closed / Lapsed |