US4673623A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Layered and homogeneous films of aluminum and aluminum/silicon with titanium and tungsten for multilevel interconnects
Assignee: Leland Stanford Junior University
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Filing: 1985-05-06
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Granted: 1987-06-16
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Expires: 2005-05-06
Abstract
Abstract Layered structures (e.g., Al-Si/Ti/Al-Si . . . ) and homogeneous alloys of aluminum and aluminum/1 at. % silicon with titanium and tungsten and other refractory metals have been found to significantly reduce hillock densities in the films when small amounts of titanium or tungsten are homogeneously added. However, the resistivity of the films can become excessive. In addition, a new type of low density hillock can form. Layering of the films eliminates all hillocks and results in films of low resistivity. Such layered and homogeneous films made with Al-Si and Ti were found to be dry etchable. Electrical shorts in test structures with two levels of metal and LPCVD SiO2 as an interlayer dielectric have been characterized and layered films using Al-Si and Ti gave excellent results.
Inventors
- 👤 Donald S. Gardner
- 👤 Krishna C. Saraswat
- 👤 Troy W. Barbee, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 18:20
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/425; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12528; Y10T428/12632; Y10T428/12736; Y10T428/12743
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
29 words
In a semiconductor device, a conductive interconnect level formed on a silicon substrate, including an aluminum silicon titanium alloy wherein said titanium is 2-3.5 at. % of said alloy.
Claim 2
Dependent Claim
29 words
In a semiconductor device, a conductive interconnect level formed on a silicon substrate, including an aluminum silicon titanium alloy wherein said titanium is 2-3.5 at. % of said alloy.
Claim 3
Dependent Claim
42 words
In a semiconductor device, a conductive formed on a silicon substrate including a homogeneous film of Al-Si with a refractory metal selected from the group consisting of titanium, tantalum, zirconium, hafnium, vanadium chromium, said titanium being 1-4 at. % of said film.
Claim 4
Dependent Claim
42 words
In a semiconductor device, a conductive formed on a silicon substrate including a homogeneous film of Al-Si with a refractory metal selected from the group consisting of titanium, tantalum, zirconium, hafnium, vanadium chromium, said titanium being 1-4 at. % of said film.
Claim 5
Dependent Claim
14 words
A semiconductor device as claimed in claim 2 wherein said refractory metal is titanium.
Claim 6
Dependent Claim
18 words
A semiconductor device as claimed in claim 3 wherein said titanium is 2-3.5 at. % of said film.
Claim 7
Dependent Claim
19 words
A semiconductor device as claimed in claim 3 wherein said titanium is about 2.5 at. % of said film.
Claim 8
Dependent Claim
17 words
A semiconductor device as claimed in claim 5 wherein said alloy includes about 1% silicon by weight.
Claim 9
Dependent Claim
30 words
An integrated circuit comprising a silicon substrate and a contact interconnect level comprising a homogeneous film of Al-Si with titanium wherein said titanium is 1-4 at. % of said film.
Claim 10
Dependent Claim
30 words
An integrated circuit comprising a silicon substrate and a contact interconnect level comprising a homogeneous film of Al-Si with titanium wherein said titanium is 1-4 at. % of said film.
Claim 11
Dependent Claim
23 words
In a semiconductor device, a conductive level formed on a silicon substrate, including alternating layers of Al-Si with layers of a refractory metal.
Claim 12
Dependent Claim
23 words
In a semiconductor device, a conductive level formed on a silicon substrate, including alternating layers of Al-Si with layers of a refractory metal.
Claim 13
Dependent Claim
14 words
A semiconductor device as claimed in claim 10 wherein said refractory metal is titanium.
Claim 14
Dependent Claim
26 words
A semiconductor device as claimed in claim 8 wherein said refractory metal is chosen from the group consisting of titanium, tantalum, zirconium, hafnium, Vanadium and chromium.
Claim 15
Dependent Claim
30 words
A semiconductor device as claimed in claim 9 wherein the conductive level is laid down on silicon or silicon dioxide, the Al-Si layer adjoining the silicon or SiO 2 layer.
Claim 16
Dependent Claim
26 words
A semiconductor device as claimed in claim 8 or 10 wherein said conductive level is formed of repeating layers of said Al-Si and said refractory metal.
Claim 17
Dependent Claim
25 words
A semiconductor device as claimed in claim 9 or 11 wherein said conductive level is formed of repeating layers of said Al-Si and said titanium.
Claim 18
Dependent Claim
15 words
A semiconductor device as claimed in claim 11 including at least two layers of titanium.
Claim 19
Dependent Claim
22 words
A semiconductor device as claimed in claims 11 or 14 including a layer of titanium on top of every layer of Al-Si.
References Cited (Backward Citations)
US4492813A
Cited
US4527184A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-15 | 1990-12-15 | 1991-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-15 | 1994-12-15 | 1995-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-15 | 1998-12-15 | 1999-06-16 | $7700.00 | Window Closed / Lapsed |