US4847674A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High speed interconnect system with refractory non-dogbone contacts and an active electromigration suppression mechanism
Assignee: Advanced Micro Devices Inc
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Filing: 1987-03-10
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Granted: 1989-07-11
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Expires: 2007-03-10
Abstract
Abstract An interconnect (16', 18', 18"), whose interlevel contacts comprise refractory (10) to refractory or refractory to semiconductor substrate (13) interfaces, comprises patterned refractory core portions (10), consisting of tungsten or molybdenum, having top portions (10a) and opposed side portions (10b), provided with sidewall spacers (32a) of aluminum, gold or copper or alloys thereof and formed on surface (12a) of insulating layers (12). The sidewall spacers afford lateral low resistivity cladding of the refractory portions as well as suppression of the electromigration failure modes of voiding and whiskering, while leaving the top portion of the core portions available for refractory to refractory contacts and the bottom portion of the core portions available for refractory to refractory or refractory to silicon contacts. In this manner, an interconnect system is provided which has low electrical resistivity but which avoids the much poorer electromigration performance associated with aluminum to aluminum, aluminum to silicon, or aluminum to refractory contact-making as well as with industry-standard bilayer structures comprising refractory/aluminum for interconnect-making.
Inventors
- 👤 Jack Sliwa
- 👤 Mohammad Farnaam
- 👤 Pankaj Dixit
- 👤 Lewis N. Shen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:01
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/064; H10W20/40; H10W20/45; H10W20/48; Y; Y10; Y10S; Y10S257/00; Y10S257/90; Y10S257/915; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12576
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
108 words
An interconnect structure for electrically connecting individual circuits and devices on an integrated circuit formed on a semiconductor substrate, said structure comprising at least one refractory core formed on an insulating layer, having a generally rectangular cross-section and having its opposed sidewalls covered and in electrical and physical contact with low resistivity fillets of at least one material selected from the group consisting of aluminum, gold and copper and alloys thereof and having its top surface available for refractory to refractory contact making and its bottom surface available for refractory to refractory contact or refractory to semiconductor contact making, said sidewall material being segmented, comprising discontinuous sections thereof.
Claim 2
Dependent Claim
108 words
An interconnect structure for electrically connecting individual circuits and devices on an integrated circuit formed on a semiconductor substrate, said structure comprising at least one refractory core formed on an insulating layer, having a generally rectangular cross-section and having its opposed sidewalls covered and in electrical and physical contact with low resistivity fillets of at least one material selected from the group consisting of aluminum, gold and copper and alloys thereof and having its top surface available for refractory to refractory contact making and its bottom surface available for refractory to refractory contact or refractory to semiconductor contact making, said sidewall material being segmented, comprising discontinuous sections thereof.
Claim 3
Dependent Claim
24 words
The interconnect of claim 1 wherein said refractory comprises a metal selected from the group consisting of tungsten, molybdenum, WSi x /W and α-Si/W.
Claim 4
Dependent Claim
10 words
The interconnect of claim 2 wherein said refractory comprises tungsten.
Claim 5
Dependent Claim
15 words
The interconnect of claim 1 wherein said sidewall material comprises aluminum or an alloy thereof.
Claim 6
Dependent Claim
10 words
The interconnect of claim 1 wherein said semiconductor comprises silicon.
Claim 7
Dependent Claim
31 words
The interconnect of claim 1 wherein said insulating layer is selected from the group consisting of undoped or doped oxides, nitride, oxynitride, polyimide, spin-on silicate and siloxane glasses and amorphous silicon.
Claim 8
Dependent Claim
26 words
The interconnect of claim 6 wherein said insulating layer comprises silicon dioxide doped with a material selected from the group consisting of phosphorus, boron/phosphorus and arsenic.
Claim 9
Dependent Claim
19 words
The interconnect of claim 1 wherein said sections are shorter than the critical length for electromigration of said material.
Claim 10
Dependent Claim
25 words
The interconnect of claim 1 wherein said sidewall comprises one of said low resistivity materials clad by at least another of said low resistivity materials.
Claim 11
Dependent Claim
19 words
The interconnect of claim 1 comprising said refractory metal formed on an adhesion layer formed on said insulating layer.
Claim 12
Dependent Claim
27 words
The interconnect of claim 10 wherein said adhesion layer comprises a material selected from the group consisting of α-Si, WSi x , titanium nitride and titanium/titanium nitride.
Claim 13
Dependent Claim
98 words
An interconnect structure for electrically connecting individual circuits and devices on an integrated circuit formed on a silicon substrate, said structure comprising at least one patterned tungsten core formed on an insulating layer, having a generally rectangular cross-section and having its opposed sidewalls covered and in electrical and physical contact with low resistivity fillets of aluminum or an alloy thereof and having its tops surface available for tungsten to tungsten contact making and its bottom surface available for tungsten to tungsten contact or tungsten to silicon contact making, said fillets of aluminum being segmented, comprising discontinuous sections thereof.
Claim 14
Dependent Claim
98 words
An interconnect structure for electrically connecting individual circuits and devices on an integrated circuit formed on a silicon substrate, said structure comprising at least one patterned tungsten core formed on an insulating layer, having a generally rectangular cross-section and having its opposed sidewalls covered and in electrical and physical contact with low resistivity fillets of aluminum or an alloy thereof and having its tops surface available for tungsten to tungsten contact making and its bottom surface available for tungsten to tungsten contact or tungsten to silicon contact making, said fillets of aluminum being segmented, comprising discontinuous sections thereof.
Claim 15
Dependent Claim
31 words
The interconnect of claim 12 wherein said insulating layer is selected from the group consisting of undoped or doped oxides, nitride, oxynitride, polyimide, spin-on silicate and siloxane glasses and amorphous silicon.
Claim 16
Dependent Claim
26 words
The interconnect of claim 13 wherein said insulating layer comprises silicon dioxide doped with a material selected from the group consisting of phosphorus, boron/phosphorus and arsenic.
Claim 17
Dependent Claim
125 words
An interconnect structure for electrically connecting individual circuits and devices on an integrated circuit formed on a semiconductor substrate, said structure comprising (a) at least one refractory core formed on an insulating layer, having a generally rectangular cross-section and having its opposed sidewalls covered and in electrical and physical contact with low resistivity fillets of at least one material selected from the group consisting of aluminum, gold and copper and alloys thereof and having its top surface available for refractory to refractory contact making and its bottom surface available for refractory to refractory contact or refractory to semiconductor contact making, said sidewall material being segmented, comprising discontinuous sections thereof and (b) at least one patterned line comprising said sidewall material, separate from said refractory core.
Claim 18
Dependent Claim
125 words
An interconnect structure for electrically connecting individual circuits and devices on an integrated circuit formed on a semiconductor substrate, said structure comprising (a) at least one refractory core formed on an insulating layer, having a generally rectangular cross-section and having its opposed sidewalls covered and in electrical and physical contact with low resistivity fillets of at least one material selected from the group consisting of aluminum, gold and copper and alloys thereof and having its top surface available for refractory to refractory contact making and its bottom surface available for refractory to refractory contact or refractory to semiconductor contact making, said sidewall material being segmented, comprising discontinuous sections thereof and (b) at least one patterned line comprising said sidewall material, separate from said refractory core.
Claim 19
Dependent Claim
24 words
The interconnect of claim 15 wherein said refractory comprises a metal selected from the group consisting of tungsten, molybdenum, WSi x /W and α-Si/W.
Claim 20
Dependent Claim
10 words
The interconnect of claim 16 wherein said refractory comprises tungsten.
Claim 21
Dependent Claim
15 words
The interconnect of claim 15 wherein said sidewall material comprises aluminum or an alloy thereof.
Claim 22
Dependent Claim
10 words
The interconnect of claim 15 wherein said semiconductor comprises silicon.
Claim 23
Dependent Claim
31 words
The interconnect of claim 15 wherein said insulating layer is selected from the group consisting of undoped or doped oxides, nitride, oxynitride, polyimide, spin-on silicate and siloxane glasses and amorphous silicon.
Claim 24
Dependent Claim
26 words
The interconnect of claim 20 wherein said insulating layer comprises silicon dioxide doped with a material selected from the group consisting of phosphorus, boron/phosphorus and arsenic.
Claim 25
Dependent Claim
19 words
The interconnect of claim 15 wherein said sections are shorter than the critical length for electromigration of said material.
Claim 26
Dependent Claim
25 words
The interconnect of claim 15 wherein said sidewall comprises one of said low resistivity materials clad by at least another of said low resistivity materials.
Claim 27
Dependent Claim
19 words
The interconnect of claim 15 comprising said refractory metal formed on an adhesion layer formed on said insulating layer.
Claim 28
Dependent Claim
27 words
The interconnect of claim 24 wherein said adhesion layer comprises a material selected from the group consisting of α-Si, WSi x , titanium nitride and titanium/titanium nitride.
Claim 29
Dependent Claim
118 words
An interconnect structure for electrically connecting individual circuits and devices on an integrated circuit formed on a silicon substrate, said structure comprising (a) at least one patterned tungsten core having a generally rectangular cross-section formed on an insulating layer and having its opposed sidewalls covered and in electrical and physical contact with low resistivity fillets of aluminum or an alloy thereof and having its top surface available for tungsten to tungsten contact making and its bottom surface available for tungsten to tungsten contact or tungsten to silicon contact making, said fillets of aluminum being segmented, comprising discontinuous sections thereof and (b) at least one patterned line comprising said aluminum or an alloy thereof, separate from said refractory core.
Claim 30
Dependent Claim
118 words
An interconnect structure for electrically connecting individual circuits and devices on an integrated circuit formed on a silicon substrate, said structure comprising (a) at least one patterned tungsten core having a generally rectangular cross-section formed on an insulating layer and having its opposed sidewalls covered and in electrical and physical contact with low resistivity fillets of aluminum or an alloy thereof and having its top surface available for tungsten to tungsten contact making and its bottom surface available for tungsten to tungsten contact or tungsten to silicon contact making, said fillets of aluminum being segmented, comprising discontinuous sections thereof and (b) at least one patterned line comprising said aluminum or an alloy thereof, separate from said refractory core.
Claim 31
Dependent Claim
31 words
The interconnect of claim 26 wherein said insulating layer is selected from the group consisting of undoped or doped oxides, nitride, oxynitride, polyimide, spin-on silicate and siloxane glasses and amorphous silicon.
Claim 32
Dependent Claim
26 words
The interconnect of claim 27 wherein said insulating layer comprises silicon dioxide doped with a material selected from the group consisting of phosphorus, boron/phosphorus and arsenic.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-10 | 1993-01-09 | 1993-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-10 | 1997-01-09 | 1997-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-10 | 2001-01-09 | 2001-07-11 | $7700.00 | Window Closed / Lapsed |