US3881971A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for fabricating aluminum interconnection metallurgy system for silicon devices
Assignee: International Business Machines Corp
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Filing: 1972-11-29
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Granted: 1975-05-06
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Expires: 1992-11-29
Abstract
Abstract A method of fabricating an improved aluminum metallurgy system of conductive stripes on a monocrystalline silicon semiconductor device that makes electrical contact with the body of the device through at least one opening in an insulating layer, wherein there is formed a blanket layer of aluminum over the insulating layer which makes contact through the monocrystalline body of silicon through at least one opening, a thin blanket layer of silicon is deposited over the layer of aluminum, selected portions of the aluminum and silicon layers are removed to define an interconnection metallurgy system, and a passivating layer of insulating material is formed over the metallurgy system. The resultant semiconductor device is capable of withstanding heat for prolonged periods of time at temperatures of up to 577* C without undergoing significant aluminum penetration into the silicon body since the silicon on the overlying layer satisfies the silicon solubility requirements of the aluminum.
Inventors
- 👤 Stuart E Greer
- 👤 Randolph H Schnitzel
- 👤 David P Waldman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:14
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/44; H10P95/00; H10W; H10W20/00; H10W20/40; H10W72/00; H10W72/20
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
175 words
A METHOD OF FABRICATING AN IMPROVED ALUMINUM METALLURGY SYSTEM OF CONDUCTIVE STRIPES ON A MONOCRYSTALLINE SILICON SEMICONDUCTOR DEVICE THAT MAKES ELECTRICAL CONTACT WITH THE BODY OF THE DEVICE THROUGH AT LEAST ONE OPENING IN AN INSULATING LAYER COMPRISING: FORMING A BLANKET LAYER OF ALUMINUM OVER SAID INSULATING LAYER WHICH MAKES CONTACT WITH THE MONOCRYSTALLINE BODY OF THE SILICON DEVICE THROUGH AT LEAST ONE OF SAID OPENINGS, DEPOSITING A THIN BLANKET LAYER OF SILICON OVER SAID LAYER OF ALUMINUM, THE THICKNESS OF SAID LAYER OF SILICON BEING SUCH THAT THE RATIO OF THE THICKNESS OF SAID ALUMINUM LAYER TO THE THICKNESS OF SAID SILICON LAYER IS IN THE RANGE OF 50 TO 1 TO 120 TO 1, REMOVING SELECTED PORTIONS OF SAID ALUMINUM AND SILICON LAYERS TO DEFINE AN INTERCONNECTION METALLURGY SYSTEMM FORMING A PASSIVATING LAYER OF INSULATING MATERIAL OVER SAID METALLURGY SYSTEM IN DIRECT CONTACT WITH SAID LAYER OF SILICON, AND SAID SEMICONDUCTOR DEVICE CAPABLE OF WITHSTANDING HEATING FOR PROLONGED PERIODS AT TEMPERATURES UP TO 577*C WITHOUT UNDERGOING SIGNIFICANT ALUMINUM PENETRATION INTO THE SILICON BODY.
Claim 2
Independent Claim
175 words
A METHOD OF FABRICATING AN IMPROVED ALUMINUM METALLURGY SYSTEM OF CONDUCTIVE STRIPES ON A MONOCRYSTALLINE SILICON SEMICONDUCTOR DEVICE THAT MAKES ELECTRICAL CONTACT WITH THE BODY OF THE DEVICE THROUGH AT LEAST ONE OPENING IN AN INSULATING LAYER COMPRISING: FORMING A BLANKET LAYER OF ALUMINUM OVER SAID INSULATING LAYER WHICH MAKES CONTACT WITH THE MONOCRYSTALLINE BODY OF THE SILICON DEVICE THROUGH AT LEAST ONE OF SAID OPENINGS, DEPOSITING A THIN BLANKET LAYER OF SILICON OVER SAID LAYER OF ALUMINUM, THE THICKNESS OF SAID LAYER OF SILICON BEING SUCH THAT THE RATIO OF THE THICKNESS OF SAID ALUMINUM LAYER TO THE THICKNESS OF SAID SILICON LAYER IS IN THE RANGE OF 50 TO 1 TO 120 TO 1, REMOVING SELECTED PORTIONS OF SAID ALUMINUM AND SILICON LAYERS TO DEFINE AN INTERCONNECTION METALLURGY SYSTEMM FORMING A PASSIVATING LAYER OF INSULATING MATERIAL OVER SAID METALLURGY SYSTEM IN DIRECT CONTACT WITH SAID LAYER OF SILICON, AND SAID SEMICONDUCTOR DEVICE CAPABLE OF WITHSTANDING HEATING FOR PROLONGED PERIODS AT TEMPERATURES UP TO 577*C WITHOUT UNDERGOING SIGNIFICANT ALUMINUM PENETRATION INTO THE SILICON BODY.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein said blanket layer is an alloy of aluminum which includes copper in an amount in the range of 2-20% by weight.
Claim 4
Dependent Claim
55 words
The method of claim 1 which further includes forming openings in said passivating layer of insulating material overlying said metallurgy system, depositing a second blanket layer of aluminum, depositing a second thin layer of silicon, and removing selected portions of said second silicon and said second aluminum layers to define a second interconnection metallurgy level.
Claim 5
Dependent Claim
36 words
The method of claim 1 wherein said silicon layer has a thickness less than 200 Angs., the selected portions of said aluminum and silicon layers are both removed by selective etching with an etchant for aluminum.
Claim 6
Dependent Claim
65 words
The method of claim 1 wherein said silicon layer has a thickness greater than 200 Angs., and a resist layer is formed over said silicon layer and subsequently exposed and developed to the configuration of desired interconnection pattern removing the exposed portions of the silicon With an etchant for silicon, and removing the resultant exposed portions of the aluminum layer with an etchant for aluminum.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein said selected portions of said silicon and aluminum layers are removed by lift-off techniques.
Claim 8
Dependent Claim
97 words
The method of claim 6 which further includes forming a layer of resist over said insulating surface layer on the monocrystalline semiconductor body prior to depositing the blanket layers of aluminum and silicon, exposing and developing the resist layer to form the reverse pattern of the desired interconnection metallurgy system, removing selected portions of said silicon and aluminum layers which have been deposited over said layer of resist by contacting the body with a solvent for said resist layer thereby removing the remaining portions of said resist and the overlying portions of said silicon and aluminum layers.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein the aluminum metallurgy pattern is formed by anodizing said masked blanket aluminum layer.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |