US3900944A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of contacting and connecting semiconductor devices in integrated circuits
Assignee: Texas Instruments Inc
•
Filing: 1973-12-19
•
Granted: 1975-08-26
•
Expires: 1993-12-19
Abstract
Abstract An improved method of forming interconnections on a semiconductor slice in which a barrier metal of TI:W or Ta is deposited followed by deposit of a conducting layer and then a masking layer of Ta after which the masking layer is patterned with photo-resist and plasma etched whereupon the conducting layer is sputter etched with the barrier layer then being removed to provide an interconnecting lead with sloping sides over which insulation and a second level of metallization may be applied without danger of problems at crossovers.
Inventors
- 👤 Clyde R Fuller
- 👤 Alan R Reinberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 19:45
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/425; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/60; H10P50/66; H10P50/663; H10P50/667; H10P95/00; H10W20/44; H10W20/4403; H10W20/4432
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
127 words
THE METHOD OF FORMING N INTERCONNECTION PATTERN ON AN INTEGRATED CIRCUIT SLICE COMPRISING THE STEPS OF: A. DEPOSITING A BARRIER LAYER OF ONE OF THE GROUP CONSISTING OF TI:W AND TA OVER SAID SLICE, B. DEPOSITING OVER SAID BARRIER LAYER A CONDUCTING LAYER C. DEPOSITING OVER SAID CONDUCTING LAYER A MASKING LAYER OF TA, D. DEVELOPING AN INTERCONNECT PARRTEN OF PHOTORESIST MATERIAL ATOP SAID MASKING LAYER OF TA, E. RF PLASMA ETCHING SAID MASKING TA LAYER IN A CF4 PLASMA, F. REMOVING SAID PHOTO-RESIST MATERIAL, G. SPUTTER ETCHING THE EXPOSED PORTIONS OF SAID CONDUCTOR LAYER SING SAID ETCHED TA LAYER AS A MASK, UNDER CONDITIONS WHICH CAUSE AN OXIDE LAYER TO FORM ON SAID MASK, AND H. ETCHING TO REMOVE TO EXPOSED PORTIONS IF SAID BARIER LAYER.
Claim 2
Independent Claim
127 words
THE METHOD OF FORMING N INTERCONNECTION PATTERN ON AN INTEGRATED CIRCUIT SLICE COMPRISING THE STEPS OF: A. DEPOSITING A BARRIER LAYER OF ONE OF THE GROUP CONSISTING OF TI:W AND TA OVER SAID SLICE, B. DEPOSITING OVER SAID BARRIER LAYER A CONDUCTING LAYER C. DEPOSITING OVER SAID CONDUCTING LAYER A MASKING LAYER OF TA, D. DEVELOPING AN INTERCONNECT PARRTEN OF PHOTORESIST MATERIAL ATOP SAID MASKING LAYER OF TA, E. RF PLASMA ETCHING SAID MASKING TA LAYER IN A CF4 PLASMA, F. REMOVING SAID PHOTO-RESIST MATERIAL, G. SPUTTER ETCHING THE EXPOSED PORTIONS OF SAID CONDUCTOR LAYER SING SAID ETCHED TA LAYER AS A MASK, UNDER CONDITIONS WHICH CAUSE AN OXIDE LAYER TO FORM ON SAID MASK, AND H. ETCHING TO REMOVE TO EXPOSED PORTIONS IF SAID BARIER LAYER.
Claim 3
Dependent Claim
28 words
The invention according to claim 1 wherein said conducting layer is sputter etched in an inert gas containing approximately 1% oxygen at 2.5 + or - 2 mili-torrs.
Claim 4
Dependent Claim
30 words
The invention according to claim 2 wherein said barrier layer is Ti:W and is removed using 30-35% H2O2 solution at a temperature in the range of 15* - 35* C.
Claim 5
Dependent Claim
49 words
The invention according to claim 1 and further including the steps of: a. depositing an insulating layer over said slice and the interconnecting pattern; and b. depositing a second layer of metallization over said insulating layer; and c. forming a second interconnection pattern in said second layer of metallization.
Claim 6
Dependent Claim
35 words
The invention according to claim 1 wherein said barrier layer is Ta and wherein said barrier layer is removed by plasma etching in CF4 thereby resulting in removal of all of said top tantalium layer.
Claim 7
Dependent Claim
12 words
The invention according to claim 1 wherein said conducting layer is gold.
References Cited (Backward Citations)
US3256588A
Cited
US3271286A
Cited
US3805375A
Cited
US3726733A
Cited
US3653999A
Cited
US3717563A
Cited
US3822467A
Cited
US3795557A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |