US6281589B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
System of selectively cleaning copper substrate surfaces, in-situ, to remove copper oxides
Assignee: Sharp Laboratories of America Inc
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Filing: 1999-03-15
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Granted: 2001-08-28
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Expires: 2019-03-15
Abstract
Abstract A system and method of selectively etching copper surfaces free of copper oxides in preparation for the deposition of an interconnecting metallic material is provided. The method removes metal oxides with beta-diketones, such as Hhfac. The Hhfac is delivered into the system in vapor form, and reacts almost exclusively to copper oxides. The by-products of the cleaning process are likewise volatile for removal from the system with a vacuum pressure. Since the process is easily adaptable to most IC process systems, it can be conducted in an oxygen-free environment, without the removal of the IC from the process chamber. The in-situ cleaning process permits a minimum amount of copper oxide to reform before the deposition of the overlying interconnection metal. In this manner, a highly conductive electrical interconnection between the copper surface and the interconnecting metal material is formed. An IC having a metal interconnection, in which the underlying copper layer is cleaned of copper oxides, in-situ with Hhfac vapor, is also provided.
Inventors
- 👤 Tue Nguyen
- 👤 Lawrence J. Charneski
- 👤 David R. Evans
- 👤 Sheng Teng Hsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:02
CPC Classifications
C; C23; C23G; C23G5/00; H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P50/286; H10P50/287; H10P50/60; H10P50/66; H10P50/663; H10P50/667; H10P70/00; H10P70/20; H10P70/23; H10P70/234; H10W; H10W20/00; H10W20/01; H10W20/031; H10P70/27
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
147 words
In an integrated circuit (IC), including a dielectric interlevel with a dielectric surface, and a plurality of metal levels underlying the dielectric interlevel, a system for the selective, in-situ, cleaning of metal oxides from a surface on a first metal level, accessed through a via from the dielectric surface to the first metal level, the system comprising: a chamber to control an atmosphere to be substantially free of oxygen, whereby the formation of metal oxides on the first metal level surface is minimized; a bubbler to introduce a β-diketone vapor into said chamber; and a wafer chuck located inside said chamber and upon which the IC is mounted, said wafer chuck having a predetermined temperature to control the temperature of the IC, whereby the β-diketone volatilizes metal oxides on the surface of the first metal level, in preparation for an electrical connection to subsequently deposited metal levels.
Claim 2
Dependent Claim
147 words
In an integrated circuit (IC), including a dielectric interlevel with a dielectric surface, and a plurality of metal levels underlying the dielectric interlevel, a system for the selective, in-situ, cleaning of metal oxides from a surface on a first metal level, accessed through a via from the dielectric surface to the first metal level, the system comprising: a chamber to control an atmosphere to be substantially free of oxygen, whereby the formation of metal oxides on the first metal level surface is minimized; a bubbler to introduce a β-diketone vapor into said chamber; and a wafer chuck located inside said chamber and upon which the IC is mounted, said wafer chuck having a predetermined temperature to control the temperature of the IC, whereby the β-diketone volatilizes metal oxides on the surface of the first metal level, in preparation for an electrical connection to subsequently deposited metal levels.
Claim 3
Dependent Claim
62 words
A system as in claim 1 in which the β-diketone vapor has the following structural formula: in which the R and R 1 groups are selected from the set of groups consisting of C1 to C6 alkyls, perfluoroalkyls, and other substitutions, and the X group is selected from the functional groups consisting of H, F, CL, Br, I, alkyls, perfluoroalkyls, and substitutions.
Claim 4
Dependent Claim
35 words
A system as in claim 2 in which the β-diketone vapor introduced by said bubbler is Hhfac, whereby metal oxides from the first metal level surface are volatilized for easy removal from the said chamber.
Claim 5
Dependent Claim
29 words
A system as in claim 3 in which said bubbler delivers the Hhfac at a pressure of less than approximately 85 Torr at a temperature of approximately 20° C.
Claim 6
Dependent Claim
21 words
A system as in claim 3 in which said wafer chuck temperature is in the range between 100 and 500° C.
Claim 7
Dependent Claim
48 words
A system as in claim 3 further comprising: e) a liquid injector to introduce liquid precursor compounds including metal into said chamber, whereby a second metal level is deposited on the first metal level surface, which is free of metal oxides, to facilitate a low resistance electrical connection.
Claim 8
Dependent Claim
61 words
A system as in claim 6 in which the liquid precursor compound introduced into said chamber to form a second metal level overlying the first metal level surface is selected from the group consisting of TiN, Tisi x N y , TaSi x N y , TaN, WN, WSi x N y , Ti, Ta, W, Cu, Al, Ag, and Au.
Claim 9
Dependent Claim
49 words
A system as in claim 3 further comprising: f) a vapor delivery system to introduce vapor precursor compounds including metal into said chamber, whereby a second metal level is deposited on the first metal level surface, which is free of metal oxides, to facilitate a low resistance electrical connection.
Claim 10
Dependent Claim
61 words
A system as in claim 8 in which the vapor precursor compound introduced into said chamber to form a second metal level overlying the first metal level surface is selected from the group consisting of TiN, TiSi x N y , TaSi x N y , TaN; WN, WSi x N y , Ti, Ta, W, Cu, Al, Ag, and Au.
Claim 11
Dependent Claim
33 words
A system as in claim 3 further comprising: a pump to create a vacuum in said chamber, whereby the volatile metal oxides of the first metal level surface are removed from said chamber.
Claim 12
Dependent Claim
22 words
A system as in claim 3 in which the first metal level is selected from the group consisting of copper and silver.
References Cited (Backward Citations)
US5019531A
Cited
EP0493754A1
Cited
EP0507074A1
Cited
US5218303A
Cited
JPH0864606A
Cited
US5736002A
Cited
US6121161A
Cited
US6204176B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-08-27 | 2005-02-26 | 2005-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-08-27 | 2009-02-26 | 2009-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-08-27 | 2013-02-26 | 2013-08-28 | $7700.00 | Window Closed / Lapsed |