US3917495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making improved planar devices including oxide-nitride composite layer
Assignee: General Electric Co
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Filing: 1974-08-16
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Granted: 1975-11-04
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Expires: 1994-08-16
Abstract
Abstract Improved method for fabricating semiconductor devices including insulating layer over semiconductor body and metallic member over insulating layer prevents degradation of insulator by impurity ion, principally alkali ion, penetration. In accord with the process, a silicon dioxide passivation layer is first formed over the surface of the semiconductor and a thin layer of amorphous silicon nitride, impervious to alkali ion penetration is deposited over the silicon dioxide. Combined steps provide insulator which has excellent insulating properties of silicon dioxide and impermeability to alkali ions of amorphous silicon nitride.
Inventors
- 👤 F Hubbard Horn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:10
CPC Classifications
H; H10; H10W; H10W74/00; H10W74/10; H10W74/131; H10D; H10D99/00; H10P; H10P95/00; H10W74/40
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
150 words
IN THE PROCESS OF FABRICATING A SEMICONDUCTOR DEVICE INCLUDING A MONOCRYSTALLINE WAFER OF A SEMICONDUCTOR MATERIAL OF A GIVEN CONDUCTIVITY TYPE HAVING AN ACTIVE MAJOR SURFACE OF RELATIVELY HIGH RESISTIVITY WITH AT LEAST ONE DISCRETE MAJOR SUFACE-ADJACENT PORTION THEREOF OF A DIFFERENT CONDUCTUCTIVITY TYPE, WITH A LAYER OF PASSIVATING-INSULATING MATERIAL COVERING SAID ACTIVE MAJOR SURFACE AND THE INTERSECTION OF SAID DIFFERENT CONDUCTIVITY REGIONS, AND HAVING A METALLIC CONTACT MEMBER IN ELECTRICAL CONTACT WITH SAID DISCRETE DSURFACWE-ADJACENT REGION AND OVERLYING AT LEAST A PORTION OF SAID INSULATING LAYER, THE IMPROVEMENT INCLUDING THE STEPS OF A FORMING OVER THE ACTIVE MAJOR SURFACE OF SAID SEMICONDUCTOR WAFER AN INSULATING-PASSIVATING LAYER OF SILICON DIOXIDE, AND B. DEPOSITING OVER SAID SILICON DIOXIDE AN AMORPHOUS LAYER OF SILICON NITRIDE WHICH IS IMPERVIOUS TO IMPURITY IONS OF THE ALKALI METAL CLASS AT ELEVATED TEMPERATURES TO PROTECT SAID SILICON DIOXIDE FROM ALKALI ION CONTAMINATION FROM DEPOSITED METALLIC CONTACTS.
Claim 2
Dependent Claim
150 words
IN THE PROCESS OF FABRICATING A SEMICONDUCTOR DEVICE INCLUDING A MONOCRYSTALLINE WAFER OF A SEMICONDUCTOR MATERIAL OF A GIVEN CONDUCTIVITY TYPE HAVING AN ACTIVE MAJOR SURFACE OF RELATIVELY HIGH RESISTIVITY WITH AT LEAST ONE DISCRETE MAJOR SUFACE-ADJACENT PORTION THEREOF OF A DIFFERENT CONDUCTUCTIVITY TYPE, WITH A LAYER OF PASSIVATING-INSULATING MATERIAL COVERING SAID ACTIVE MAJOR SURFACE AND THE INTERSECTION OF SAID DIFFERENT CONDUCTIVITY REGIONS, AND HAVING A METALLIC CONTACT MEMBER IN ELECTRICAL CONTACT WITH SAID DISCRETE DSURFACWE-ADJACENT REGION AND OVERLYING AT LEAST A PORTION OF SAID INSULATING LAYER, THE IMPROVEMENT INCLUDING THE STEPS OF A FORMING OVER THE ACTIVE MAJOR SURFACE OF SAID SEMICONDUCTOR WAFER AN INSULATING-PASSIVATING LAYER OF SILICON DIOXIDE, AND B. DEPOSITING OVER SAID SILICON DIOXIDE AN AMORPHOUS LAYER OF SILICON NITRIDE WHICH IS IMPERVIOUS TO IMPURITY IONS OF THE ALKALI METAL CLASS AT ELEVATED TEMPERATURES TO PROTECT SAID SILICON DIOXIDE FROM ALKALI ION CONTAMINATION FROM DEPOSITED METALLIC CONTACTS.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein said silicon nitride layer is impervious to alkali metals at temperatures of the order of 500*C-600*C.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein said semiconductor material is silicon.
Claim 5
Dependent Claim
41 words
The process of claim 1 wherein said silicon dioxide insulating layer is formed to a thickness of approximately 1000 A.U. to 10,000 A.U. thick and said silicon nitride film is deposited to a thickness of approximately 50 to 500 A.U. thick.
Claim 6
Dependent Claim
22 words
The process of claim 4 wherein said silicon nitride film is deposited to a thickness of approximately 200 to 500 A.U. thick.
Claim 7
Dependent Claim
35 words
The process of claim 1 wherein said silicon nitride layer is deposited by a vapor phase reaction at the vicinity of the silicon dioxide layer, said reaction occurring between separate sources of silicon and nitrogen.
Claim 8
Dependent Claim
33 words
The process of claim 6 wherein said silicon nitride layer is deposited by the pyrolysis of a silicon containing compound in the presence of ammonia at a temperature of approximately 800* to 1100*C.
Claim 9
Dependent Claim
12 words
The process of claim 7 wherein said silicon containing compound is silane.
Claim 10
Dependent Claim
80 words
The process of claim 6 and including the further steps of a. sequentially etching at least one aperture in said silicon nitride and said silicon dioxide films to expose the active surface of said semiconductor body; b. diffusing a conductivity modifying activator impurity through said aperture to form said different conductivity surface-adjacent region; c. forming a metallic contact member in electrical contact with said dIfferent conductivity active surface-adjacent region and overlying at least a portion of said silicon nitride layer.
Claim 11
Dependent Claim
14 words
The process of claim 6 wherein said metallic contact member is made of aluminum.
Claim 12
Dependent Claim
49 words
The process of claim 6 wherein a plurality of etching and diffusion steps are performed sequentially and wherein a layer of silicon dioxide is formed upon the exposed semiconductor surface after each diffusion step and an alkali ion-impervious layer of silicon nitride is deposited over said silicon dioxide film.
Claim 13
Dependent Claim
90 words
The process of claim 11 wherein a first active surface-adjacent region is impurity-diffused to a first predetermined depth to create a first active surface-adjacent region of a conductivity type different from that of said wafer, a second active surface-adjacent region within and of lesser surface dimension is impurity-diffused to a second predetermined depth to create an active surface-adjacent region of a conductivity type different from said first impurity diffused region, and separate contact members are made to each of said regions and to said active major surface of said wafer.
Claim 14
Dependent Claim
51 words
The process of claim 6 wherein a plurality of separate apertures are simultaneously etched through each of said silicon nitride and said silicon dioxide layers and a conductivity modifying impurity is simultaneously diffused through said apertures to create a plurality of active surface-adjacent regions of different conductivity characteristics than said wafer.
Claim 15
Dependent Claim
47 words
The process of claim 13 wherein two such apertures are very closely spaced, and said active surface-adjacent regions are diffused with conductivity modifying impurities to render the conductivity type thereof opposite to that of said wafer and to form source and drain regions of a field-effect transistor.
Claim 16
Dependent Claim
11 words
The process of claim 6 wherein said semiconductor body is silicon.
Claim 17
Dependent Claim
40 words
The process of claim 6 wherein said silicon dioxide insulating layer is formed to a thickness of approximately 1000 A.U. to 10,000 A.U. and said silicon nitride film is deposited to a thickness of approximately 50 to 500 A.U. thick.
Claim 18
Dependent Claim
22 words
The process of claim 16 wherein said silicon nitride film is deposited to a thickness of approximately 200 to 500 A.U. thick.
Claim 19
Dependent Claim
75 words
The process of claim 1 including the further steps of a. sequentially etching a plurality of separate apertures through each of said silicon nitride and said silicon dioxide layers to expose the active surface of said semiconductor body; b. diffusing a conductivity modifying activator impurity through said apertures to form said different conductivity surface-adjacent regions; and c. forming a metallic electrode over said silicon nitride layer in at least a region between two adjacent apertures.
Claim 20
Dependent Claim
28 words
The process of claim 18 including the further step of a. forming separate contact members to each of said different conductivity surface-adjacent regions and to said metallic electrode.
Claim 21
Dependent Claim
14 words
The process of claim 19 wherein said metallic contact member is made of aluminum.
Claim 22
Dependent Claim
37 words
The process of claim 18 wherein said silicon dioxide is formed to a thickness of several hundred to more than 1000 A.U. and said silicon nitride is deposited to a thickness of approximately 200 to 500 A.U.
References Cited (Backward Citations)
US3477886A
Cited
US3419761A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-03 | 1979-05-05 | 1979-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-03 | 1983-05-05 | 1983-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-03 | 1987-05-05 | 1987-11-04 | $7700.00 | Window Closed / Lapsed |