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US5882498A
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Method for reducing oxidation of electroplating chamber contacts and improving uniform electroplating of a substrate
Assignee: Advanced Micro Devices Inc
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Filing: 1997-10-16
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Granted: 1999-03-16
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Expires: 2017-10-16
Abstract
Abstract A method for electroplating a silicon substrate in manufacturing a semiconductive device is provided. Electroplating process chamber contacts or fingers used in positioning a silicon substrate or wafer during an electroplating process are plated with a metal layer to prevent oxidation of the contacts. Oxidation of the contacts may result in increased and varying resistance of the contacts and thus nonuniform plating of the silicon wafer and possibly even deplating of a seed layer. A 20 mA/cm 2 current is applied to the contacts which are immersed in an electrolyte solution before loading a silicon wafer. A silicon wafer is then loaded into the electroplating process chamber containing the electrolyte solution. The preplating of the contacts enables the formation of a uniform metal layer on the silicon substrate. Additionally, voltage then may be applied to the contacts after unloading the silicon wafer to reduce oxidation. This electroplating method reduces expensive maintenance time in replacing or cleaning electroplating chamber contacts. The method also does not require expensive and complex electronics to monitor and supply current to the contacts.
Inventors
- 👤 Valery Dubin
- 👤 Takeshi Nogami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:21
CPC Classifications
C; C23; C23C; C23C28/00; C23C28/02; C23C28/023; C23C28/021; C25; C25D; C25D7/00; C25D7/12; C25D7/123
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
70 words
A method for electroplating a substrate, comprising the steps of: (a) immersing a contact for positioning the substrate into an electrolyte solution; (b) applying a first current amount to the contact for plating only the contact with a metal layer; (c) positioning the substrate with the plated contact in the electrolyte solution; and (d) applying a second current amount to the substrate for forming a metal layer on the substrate.
Claim 2
Independent Claim
70 words
A method for electroplating a substrate, comprising the steps of: (a) immersing a contact for positioning the substrate into an electrolyte solution; (b) applying a first current amount to the contact for plating only the contact with a metal layer; (c) positioning the substrate with the plated contact in the electrolyte solution; and (d) applying a second current amount to the substrate for forming a metal layer on the substrate.
Claim 3
Dependent Claim
17 words
The method of claim 1, wherein the metal layer on the contact and the substrate is copper.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein the metal layer on the contact and the substrate is nickel.
Claim 5
Dependent Claim
17 words
The method of claim 1, wherein the metal layer on the contact and the substrate is cobalt.
Claim 6
Dependent Claim
19 words
The method of claim 1, wherein the metal layer on the contact and the substrate is tin-lead (SnPb) alloy.
Claim 7
Dependent Claim
16 words
The method of claim 1, wherein the first current amount is approximately 20 mA/cm 2 .
Claim 8
Dependent Claim
17 words
The method of claim 2, wherein the copper layer on the substrate is approximately 1.5 μm thick.
Claim 9
Dependent Claim
13 words
The method of claim 2, wherein the copper is uniform within approximately 5%.
Claim 10
Dependent Claim
14 words
The method of claim 1 wherein the substrate is an approximately 8" silicon wafer.
Claim 11
Dependent Claim
20 words
The method of claim 9, wherein the silicon wafer includes a trench having a barrier layer and a seed layer.
Claim 12
Dependent Claim
47 words
The method of claim 1, further including the steps of: (e) removing the contact and substrate from the electrolyte solution; (f) removing the substrate from the contact; (g) immersing the contact into the electrolyte solution; and, (h) applying less than approximately 15 mA/cm 2 to the contact.
Claim 13
Dependent Claim
39 words
The method of claim 1, further including the steps of: (e) removing the contact and substrate from the electrolyte solution; (f) removing the substrate from the contact; and, (g) applying approximately 1.5 to approximately 2.0 V to the contact.
Claim 14
Independent Claim
129 words
A method for electroplating a silicon wafer with a copper layer using an electroplating process chamber having a plurality of contacts and containing a copper electrolyte solution, comprising the steps of: (a) immersing the plurality of contacts into the copper electrolyte solution; (b) applying an approximately 20 mA/cm 2 current to the plurality of contacts for plating only the plurality of contacts with a layer of copper; (c) removing the plurality of copper plated contacts from the copper electrolyte solution; (d) positioning the silicon wafer on the plurality of copper plated contacts; (e) immersing the plurality of copper plated contacts and silicon wafer into the electrolyte solution; and, (f) applying a current to the plurality of copper plated contacts for plating the silicon wafer with the layer of copper.
Claim 15
Independent Claim
129 words
A method for electroplating a silicon wafer with a copper layer using an electroplating process chamber having a plurality of contacts and containing a copper electrolyte solution, comprising the steps of: (a) immersing the plurality of contacts into the copper electrolyte solution; (b) applying an approximately 20 mA/cm 2 current to the plurality of contacts for plating only the plurality of contacts with a layer of copper; (c) removing the plurality of copper plated contacts from the copper electrolyte solution; (d) positioning the silicon wafer on the plurality of copper plated contacts; (e) immersing the plurality of copper plated contacts and silicon wafer into the electrolyte solution; and, (f) applying a current to the plurality of copper plated contacts for plating the silicon wafer with the layer of copper.
Claim 16
Dependent Claim
50 words
The method of claim 13, further including the steps of: (g) removing the plurality of contacts and the silicon wafer from the electrolyte solution; (h) immersing the plurality of contacts into the electrolyte solution; and, (i) applying an approximately less than 15 mA/cm 2 current to the plurality of contacts.
Claim 17
Dependent Claim
49 words
The method of claim 13, further including the steps of: (g) removing the plurality of contacts and the silicon wafer from the electrolyte solution; (h) removing the silicon wafer from the contacts; and, (i) applying a voltage of approximately 1.5 to approximately 2.0 V to the plurality of contacts.
Claim 18
Dependent Claim
45 words
The method of claim 13, wherein the method further includes the steps of: (g) forming a trench in an interlevel dielectric in the silicon wafer; (h) forming a tantalum layer on the silicon wafer; and, (i) forming a copper seed layer on the tantalum layer.
Claim 19
Dependent Claim
15 words
The method of claim 16, wherein the copper seed layer is approximately 100 nm thick.
Claim 20
Dependent Claim
14 words
The method of claim 16, wherein the tantalum layer is approximately 30 nm thick.
Claim 21
Dependent Claim
13 words
The method of claim 13, wherein the plurality of contacts includes 6 contacts.
Claim 22
Dependent Claim
20 words
The method of claim 13, wherein the copper layer of the silicon wafer is uniform within approximately 5%, 1 sigma.
Claim 23
Dependent Claim
15 words
The method of claim 13, wherein the silicon wafer is an approximately 8" silicon wafer.
References Cited (Backward Citations)
US5429733A
Cited
US5472592A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-03-15 | 2002-09-14 | 2003-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-15 | 2006-09-14 | 2007-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-15 | 2010-09-14 | 2011-03-16 | $7700.00 | Window Closed / Lapsed |