US3856648A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming contact and interconnect geometries for semiconductor devices and integrated circuits
Assignee: Texas Instruments Inc
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Filing: 1973-12-19
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Granted: 1974-12-24
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Expires: 1993-12-19
Abstract
Abstract An improved method of forming interconnections on a semiconductor slice containing a plurality of devices in which layers of Ti:W, a conducting metal and Ti:W are deposited, the interconnections masked using aluminum, the top Ti:W layer removed, the conducting layer sputter etched, and the bottom layer of TI:W then removed resulting in an interconnection geometry which maintains adequate control of conductor width and spacing and avoids problems at crossovers when forming multiple level connections.
Inventors
- 👤 C Fuller
- 👤 P Ghate
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:18
CPC Classifications
H; H10; H10P; H10P95/00; H10P14/00; H10P14/60; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6329; H10P14/6334; H10P14/6336; H10P14/66; H10P14/662; H10P14/668; H10P14/6681; H10P14/6682; H10P14/69; H10P14/692; H10P14/6921; H10P14/69215; H10P14/694; H10P14/6943; H10P14/69433; H10W; H10W20/00; H10W20/40
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
108 words
A METHOD OF FORMING INTERCONNECTIONS ON A SEMICONDUCFOR SLICE, COMPRISING: A. DEPOSITING A LAYER OF TI:W ON SAID SLICE; B. DEPOSITING OVER SAID LAYER A CONDUCTOR METAL HAVING A HIGH CONDUCTIVITY; C. DEPOSITING OVER SAID CONDUCTOR METAL A SECOND LAYER OF TI:W, D. DEPOSITING OVER SAID LAYER OF TI:W A LAYER OF ALUMINUM; E. PHOTOLITHOGRAPHICALLY PATTERNING AND WET CHEMICALLY ETCHING SAID ALUMINUM TO LEAVE AN ALUMINUM PATTERN REPRESENTING THE DESIRED INTERCONNECTION PATTERN ON THE SLICE; F. REMOVING HE EXPOSED PORTIONS OF SAID SECOND LAYER OF TI:W, G. SPUTTER ETCHING THE EXPOSED PORTIONS OF SAID CONDUCTOR LAYER; AND H. REMOVING THE EXPOSED PORTIONS OF SAID FIRST LAYER OF TI:W.
Claim 2
Independent Claim
108 words
A METHOD OF FORMING INTERCONNECTIONS ON A SEMICONDUCFOR SLICE, COMPRISING: A. DEPOSITING A LAYER OF TI:W ON SAID SLICE; B. DEPOSITING OVER SAID LAYER A CONDUCTOR METAL HAVING A HIGH CONDUCTIVITY; C. DEPOSITING OVER SAID CONDUCTOR METAL A SECOND LAYER OF TI:W, D. DEPOSITING OVER SAID LAYER OF TI:W A LAYER OF ALUMINUM; E. PHOTOLITHOGRAPHICALLY PATTERNING AND WET CHEMICALLY ETCHING SAID ALUMINUM TO LEAVE AN ALUMINUM PATTERN REPRESENTING THE DESIRED INTERCONNECTION PATTERN ON THE SLICE; F. REMOVING HE EXPOSED PORTIONS OF SAID SECOND LAYER OF TI:W, G. SPUTTER ETCHING THE EXPOSED PORTIONS OF SAID CONDUCTOR LAYER; AND H. REMOVING THE EXPOSED PORTIONS OF SAID FIRST LAYER OF TI:W.
Claim 3
Dependent Claim
27 words
The invention according to claim 1 and further including the step of removing the remaining aluminum and depositing over said slice a layer of dielectric insulating material.
Claim 4
Dependent Claim
21 words
The invention according to claim 2 wherein said dielectric material comprises SiO2 deposited using C.V.D. from an SiH4 + O2 reaction.
Claim 5
Dependent Claim
30 words
The invention according to claim 2 wherein said insulating dielectric is deposited by RF sputtering an SiO2 layer and depositing a layer of SiO2 by C.V.D. of Silane + O2.
Claim 6
Dependent Claim
28 words
The invention according to claim 2 wherein said insulating layer comprises a film of plasma vapor deposited silicon nitride and a layer of silane SiO2 formed by C.V.D.
Claim 7
Dependent Claim
25 words
The invention according to claim 5 wherein said nitride layer is between 1,500 and 1,800 angstroms thick and said silane SiO2 layer 5,000-10,000 angstroms thick.
Claim 8
Dependent Claim
31 words
The invention according to claim 1 wherein said sputtering pressure is less than 5 mili torr and the sputtering gas comprises an inert gas with 0.5 - 5% O2 mixed therewith.
Claim 9
Dependent Claim
21 words
The invention according to claim 1 wherein said conductor layer is one of the group consisting of copper, gold and silver.
Claim 10
Dependent Claim
12 words
The invention according to claim 8 wherein said conductor layer is gold.
Claim 11
Dependent Claim
16 words
The invention according to claim 1 wherein said first and second Ti:W layers are sputter etched.
Claim 12
Dependent Claim
21 words
The invention according to claim 1 wherein said second Ti:W layer is wet etched and said first Ti:W layer sputter etched.
Claim 13
Dependent Claim
19 words
The invention according to claim 1 wherein said first and second Ti:W layers are plasma vapor etched in CF4.
Claim 14
Dependent Claim
17 words
The invention according to claim 1 wherein both said first and second Ti:W layers are wet etched.
Claim 15
Dependent Claim
22 words
The invention according to claim 1 wherein said second Ti:W layer is plasma etched and said first Ti:W layer is wet etched.
Claim 16
Dependent Claim
25 words
The invention according to claim 1 wherein said top Ti:W layer is wet etched and said bottom Ti:W layer is plasma vapor etched in CF4.
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) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |