US5646448A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copper pellet for reducing electromigration effects associated with a conductive via in a semiconductor device
Assignee: Advanced Micro Devices Inc
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Filing: 1996-08-19
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Granted: 1997-07-08
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Expires: 2016-08-19
Abstract
Abstract A multilayer semiconductor structure includes a conductive via. The conductive via includes a pellet of metal having a high resistance to electromigration. The pellet is made from a conformal layer of copper or gold deposited over the via to form a copper or gold reservoir or contact located in the via. A barrier layer is provided between the reservoir and an insulating layer to prevent the pellet from diffusing into the insulating layer. The pellet can be formed by selective deposition or by etching a conformal layer. The conformal layer can be deposited by sputtering, collimated sputtering, chemical vapor deposition (CVD), dipping, evaporating, or by other means. The barrier layer and pellet may be etched by anisotropic dry etching, plasma-assisted etching, or other layer removal techniques.
Inventors
- 👤 Richard K. Klein
- 👤 Darrell Erb
- 👤 Steven Avanzino
- 👤 Robin Cheung
- 👤 Scott Luning
- 👤 Bryan Tracy
- 👤 Subhash Gupta
- 👤 Ming-Ren Lin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:44
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/083; H10W20/031; H10W20/056; Y; Y10; Y10S; Y10S257/00; Y10S257/915; Y10S438/00; Y10S438/927
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
143 words
In a multilayer semiconductor structure including a barrier layer formed over a conductive line, and an insulating layer formed over the barrier layer, the barrier layer preventing diffusion, the insulating layer having a via extending through the insulating layer and the barrier layer, the barrier layer having a top side adjacent the insulating layer and a bottom side adjacent the conductive line, the improvement comprising: a pellet of metal having a high resistance to electromigration situated within the via at a bottom end of the via, the pellet having a top side located beneath the top side of the barrier layer and a bottom side coupled to the conductive line, the pellet being physically isolated from the insulating layer whereby the pellet reduces electromigration failures associated with the conductive line, wherein the via is filled with an aluminum plug located above the pellet.
Claim 2
Dependent Claim
143 words
In a multilayer semiconductor structure including a barrier layer formed over a conductive line, and an insulating layer formed over the barrier layer, the barrier layer preventing diffusion, the insulating layer having a via extending through the insulating layer and the barrier layer, the barrier layer having a top side adjacent the insulating layer and a bottom side adjacent the conductive line, the improvement comprising: a pellet of metal having a high resistance to electromigration situated within the via at a bottom end of the via, the pellet having a top side located beneath the top side of the barrier layer and a bottom side coupled to the conductive line, the pellet being physically isolated from the insulating layer whereby the pellet reduces electromigration failures associated with the conductive line, wherein the via is filled with an aluminum plug located above the pellet.
Claim 3
Dependent Claim
10 words
The improvement of claim 1 wherein the metal includes copper.
Claim 4
Dependent Claim
13 words
The improvement of claim 1 wherein the metal includes copper, gold, or silver.
Claim 5
Dependent Claim
19 words
The improvement of claim 1 wherein the top side of the pellet is directly coupled to the aluminum plug.
Claim 6
Dependent Claim
17 words
The improvement of claim 4 wherein the bottom of the pellet is connected to the conductive line.
Claim 7
Dependent Claim
13 words
The improvement of claim 1 wherein the conductive line is doped with copper.
Claim 8
Dependent Claim
32 words
The improvement of claim 6 wherein the conductive line is comprised of a 250 Angstrom thick bottom layer of titanium, and a 4000 Angstrom thick top layer of aluminum doped with copper.
Claim 9
Dependent Claim
29 words
The improvement of claim 1 wherein the conductive line is comprised of titanium, aluminum and copper, the barrier layer is titanium nitride, and the insulating layer is silicon dioxide.
Claim 10
Dependent Claim
144 words
A multilayer integrated circuit, comprising: a metal conductive line; a barrier layer formed over the conductive line, the barrier layer preventing diffusion; an insulating layer formed over the barrier layer, the insulating layer having a via extending through the insulating layer and the barrier layer, the barrier layer having a top side adjacent the insulating layer and a bottom side adjacent the conductive line; and a pellet of metal having a high resistance to electromigration situated within the via at the bottom end of the via, the pellet having a top side located beneath the top side of the barrier layer and a bottom side in contact with the conductive line, the pellet being physically isolated from the insulating layer whereby the pellet reduces electromigration failures associated with the conductive line, wherein the via is filled with an aluminum plug located above the pellet.
Claim 11
Dependent Claim
144 words
A multilayer integrated circuit, comprising: a metal conductive line; a barrier layer formed over the conductive line, the barrier layer preventing diffusion; an insulating layer formed over the barrier layer, the insulating layer having a via extending through the insulating layer and the barrier layer, the barrier layer having a top side adjacent the insulating layer and a bottom side adjacent the conductive line; and a pellet of metal having a high resistance to electromigration situated within the via at the bottom end of the via, the pellet having a top side located beneath the top side of the barrier layer and a bottom side in contact with the conductive line, the pellet being physically isolated from the insulating layer whereby the pellet reduces electromigration failures associated with the conductive line, wherein the via is filled with an aluminum plug located above the pellet.
Claim 12
Dependent Claim
12 words
The multilayer semiconductor structure of claim 9 wherein the metal includes copper.
Claim 13
Dependent Claim
15 words
The multilayer semiconductor structure of claim 9 wherein the metal includes copper, gold or silver.
Claim 14
Dependent Claim
14 words
The multilayer semiconductor structure of claim 9 wherein the via includes a barrier wall.
Claim 15
Dependent Claim
20 words
The multilayer semiconductor structure of claim 12 wherein a bottom side of the pellet is connected to the conductive line.
Claim 16
Dependent Claim
15 words
The multilayer semiconductor structure of claim 9 wherein the conductive line is doped with copper.
Claim 17
Dependent Claim
31 words
The multilayer semiconductor structure of claim 9 wherein the conductive line is comprised of titanium, aluminum and copper, the barrier layer is titanium nitride, and the insulating layer is silicon dioxide.
Claim 18
Dependent Claim
34 words
The multilayer semiconductor structure of claim 15 wherein the conductive line is comprised of a 250 Angstrom thick bottom layer of titanium and a 4000 Angstrom thick top layer of aluminum doped with copper.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-07-07 | 2001-01-06 | 2001-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-07-07 | 2005-01-06 | 2005-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-07-07 | 2009-01-06 | 2009-07-08 | $7700.00 | Window Closed / Lapsed |