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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
•
Filing: 1973-12-19
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Granted: 1974-12-24
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Expires: 1993-12-19
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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 2026-11-05 21:00
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)

US3442701A Cited
US3616401A Cited
US3653999A Cited

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

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