US6387805B2
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Copper alloy seed layer for copper metallization
Assignee: Applied Materials Inc
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Filing: 1997-06-18
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Granted: 2002-05-14
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Expires: 2017-06-18
Abstract
Abstract A copper metallization structure and its method of formation in which a layer of a copper alloy, such as Cu—Mg or Cu—Al is deposited over a silicon oxide based dielectric layer and a substantially pure copper layer is deposited over the copper alloy layer. The copper alloy layer serves as a seed or wetting layer for subsequent filling of via holes and trenches with substantially pure copper. Preferably, the copper alloy is deposited cold in a sputter process, but, during the deposition of the pure copper layer or afterwards in a separate annealing step, the temperature is raised sufficiently high to cause the alloying element of the copper alloy to migrate to the dielectric layer and form a barrier there against diffusion of copper into and through the dielectric layer. This barrier also promotes adhesion of the alloy layer to the dielectric layer, thereby forming a superior wetting and seed layer for subsequent copper full-fill techniques. Filling of the alloy-lined feature can be accomplished using PVD, CVD, or electro/electroless plating.
Inventors
- 👤 Peijun Ding
- 👤 Tony Chiang
- 👤 Imran Hashim
- 👤 Bingxi Sun
- 👤 Barry Chin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:11
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/033; C; C23; C23C; C23C14/00; C23C14/02; C23C14/024; C23C14/025; C23C14/06; C23C14/14; C23C14/16; C23C14/165; C23C14/22; C23C14/54; C23C14/541; C23C16/00; C23C16/02; C23C16/0272; C23C16/0281; C23C16/06; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/43; H10W20/042; H10W20/055; H10W20/056; H10W20/064; H10W20/065; H10W20/071; H10W20/074; H10W20/076; H10W20/077; H10W20/40; H10W20/41; H10W20/425; H10W20/44; H10W20/4403; H10W20/4421; H10W20/4424; H10P14/44
Claims Analysis
Total Claims: 41
Claim 1
Independent Claim
58 words
A method of forming a copper metallization, comprising the steps of: a first step of sputter depositing onto a dielectric part of a substrate comprising silicon and oxygen a copper alloy layer comprising copper and less than 10 atomic percent of an alloying element; and a second step of depositing onto said copper alloy layer a copper layer.
Claim 2
Independent Claim
58 words
A method of forming a copper metallization, comprising the steps of: a first step of sputter depositing onto a dielectric part of a substrate comprising silicon and oxygen a copper alloy layer comprising copper and less than 10 atomic percent of an alloying element; and a second step of depositing onto said copper alloy layer a copper layer.
Claim 3
Dependent Claim
15 words
The method of claim 1 , wherein said copper layer consists of substantially pure copper.
Claim 4
Dependent Claim
25 words
The method of claim 1 , wherein said first step is performed while maintaining said substrate at a temperature equal to or above 200° C.
Claim 5
Dependent Claim
15 words
The method of claim 3 , wherein said temperature is no more than 400° C.
Claim 6
Dependent Claim
13 words
The method of claim 1 , wherein said second step comprises plating copper.
Claim 7
Dependent Claim
16 words
The method of claim 1 , wherein said second step comprises chemical vapor deposition of copper.
Claim 8
Dependent Claim
16 words
The method of claim 1 , wherein said second step comprises physical vapor deposition of copper.
Claim 9
Dependent Claim
46 words
The method of claim 7 , wherein said first step is performed while holding said substrate at a first temperature that is substantially lower than a second temperature in said second step sufficiently high to cause said alloying element to diffuse in said copper alloy layer.
Claim 10
Dependent Claim
15 words
The method of claim 8 , wherein said first temperature is less than 200° C.
Claim 11
Dependent Claim
15 words
The method of claim 9 , wherein said first temperature is less than 100° C.
Claim 12
Dependent Claim
27 words
The method of claim 1 , further comprising annealing said structure after said second step to cause said alloying element to diffuse in said copper alloy layer.
Claim 13
Dependent Claim
22 words
The method of claim 1 , wherein said first step is performed while holding said substrate at a temperature below 200° C.
Claim 14
Dependent Claim
47 words
The method of claim 1 , wherein said dielectric part of said substrate includes an aperture therein, wherein said first step deposits said copper alloy layer on sides of said aperture, and wherein said second step deposits said copper in said aperture onto said copper alloy layer.
Claim 15
Dependent Claim
16 words
The method of claim 1 , wherein said copper alloy layer directly contacts said dielectric part.
Claim 16
Dependent Claim
24 words
The method of claim 1 , wherein said alloying element is selected from the group consisting of magnesium, aluminum, boron, tantalum, tellurium, and titanium.
Claim 17
Dependent Claim
20 words
The method of claim 15 , wherein said alloying element is selected from the group consisting of magnesium and aluminum.
Claim 18
Dependent Claim
12 words
The method of claim 16 , wherein said alloying element comprises magnesium.
Claim 19
Dependent Claim
12 words
The method of claim 16 , wherein said alloying element comprises aluminum.
Claim 20
Independent Claim
51 words
A method of forming a metallization layer in an aperture formed in a dielectric part of a substrate comprising silicon and oxygen, said method comprising sputter depositing onto sides and a bottom of said aperture a copper alloy layer comprising copper and less than 10 atomic percent of an alloying element.
Claim 21
Independent Claim
51 words
A method of forming a metallization layer in an aperture formed in a dielectric part of a substrate comprising silicon and oxygen, said method comprising sputter depositing onto sides and a bottom of said aperture a copper alloy layer comprising copper and less than 10 atomic percent of an alloying element.
Claim 22
Dependent Claim
12 words
The method of claim 19 , wherein said alloying element comprises magnesium.
Claim 23
Dependent Claim
26 words
The method of claim 20 , wherein said magnesium is present in said copper alloy layer in an amount of between 0.05 and 6 atomic percent.
Claim 24
Dependent Claim
12 words
The method of claim 19 , wherein said alloying element comprises aluminum.
Claim 25
Dependent Claim
26 words
The method of claim 22 , wherein said aluminum is present in said copper alloy layer in an amount of between 0.05 and 0.3 atomic percent.
Claim 26
Dependent Claim
22 words
The method of claim 19 , wherein said alloying element is selected from the group consisting of boron, tantalum, tellurium, and titanium.
Claim 27
Dependent Claim
20 words
The method of claim 19 , wherein said copper alloy layer has a thickness of no more than 100 nm.
Claim 28
Dependent Claim
19 words
The method of claim 25 , wherein said copper alloy layer is sputter deposited directly onto said dielectric part.
Claim 29
Dependent Claim
15 words
The method of claim 25 , wherein said thickness is no more than 50 nm.
Claim 30
Dependent Claim
15 words
The method of claim 27 , wherein said thickness is no more than 10 nm.
Claim 31
Dependent Claim
27 words
The method of claim 19 , further comprising a subsequent step of filling copper into a portion of said hole not occupied by said copper alloy layer.
Claim 32
Dependent Claim
19 words
The method of claim 29 , wherein said filling step fills 99 atomic percent pure copper into said portion.
Claim 33
Dependent Claim
17 words
The method of claim 29 , wherein said sputtering and filling steps are performed at different temperatures.
Claim 34
Dependent Claim
12 words
The method of claim 29 , wherein said filling step comprises electroplating.
Claim 35
Dependent Claim
28 words
The method of claim 32 , wherein said alloying element comprises magnesium present in said copper alloy layer in an amount of between 0.05 and 6 atomic percent.
Claim 36
Dependent Claim
28 words
The method of claim 32 , wherein said alloying element comprises aluminum present in said copper alloy layer in an amount of between 0.05 and 0.3 atomic percent.
Claim 37
Dependent Claim
16 words
The method of claim 19 , wherein said copper alloy layer directly contacts said dielectric part.
Claim 38
Dependent Claim
24 words
The method of claim 19 , wherein a free space is formed between said copper alloy layer deposited on said sides of said aperture.
Claim 39
Dependent Claim
31 words
The method of claim 19 , including maintaining said copper alloy layer at a temperature causing said alloying element to diffuse to a side of said aperture adjacent said dielectric part.
Claim 40
Independent Claim
86 words
A method of forming a copper vertical interconnect in a hole extending through a silicon oxide layer, comprising the steps of: a first step of sputtering depositing onto sides of said hole a copper alloy layer having a thickness of no more than 100 nm and comprising copper and less than 10 atomic percent of an alloying element selected from the group consisting of aluminum, magnesium, boron, tantalum, tellurium, and titanium; and a subsequent second step of depositing onto said copper alloy layer a layer of
Claim 41
Independent Claim
86 words
A method of forming a copper vertical interconnect in a hole extending through a silicon oxide layer, comprising the steps of: a first step of sputtering depositing onto sides of said hole a copper alloy layer having a thickness of no more than 100 nm and comprising copper and less than 10 atomic percent of an alloying element selected from the group consisting of aluminum, magnesium, boron, tantalum, tellurium, and titanium; and a subsequent second step of depositing onto said copper alloy layer a layer of
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