US3861969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making III{14 V compound semiconductor devices
Assignee: Hitachi Ltd
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Filing: 1973-11-23
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Granted: 1975-01-21
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Expires: 1993-11-23
Abstract
Abstract On a surface of a III-V compound semiconductor substrate an Si3N4 layer is first deposited by a chemical vapor deposition method at a temperature between 600* and 800*C with a relatively low flow rate of SiH4 and NH3, so as to have a growth rate of the Si3N4 layer less than about 100 A/min. Then a phosphosilicate glass layer is deposited on the Si3N4 layer also by a chemical vapor deposition method. A double layer of Si3N4 and phosphosilicate glass thus formed serves as protective layer and/or mask for the selective diffusion, whereby such double layer avoids a warping of the substrate.
Inventors
- 👤 Yuichi Ono
- 👤 Kazuhiro Kurata
- 👤 Masahiko Ogirima
- 👤 Toshimitu Shinoda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:38
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10D; H10D84/00; H10D84/01; H10D84/02; H10D84/05; H10H; H10H20/00; H10H20/80; H10W74/00; H10W74/40; H10W74/43; Y; Y10; Y10S; Y10S148/00; Y10S148/007; Y10S148/043; Y10S148/049; Y10S148/065; Y10S148/097; Y10S148/106; Y10S148/113; Y10S148/114; Y10S252/00; Y10S252/95; Y10S252/951; Y10S438/00; Y10S438/91; Y10S438/938
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
235 words
A METHOD FOR MAKING III-V COMPOUND SEMICONDUCTOR DEVICES COMPRISING THE STEPS OF: A. PREPARING A SEMICONDUCTOR SUBSTRATE MADE OF A III-V COMPOUND OF FIRST CONDUCTIVITY TYPE; B. DEPOSITING AN SI3N4 LAYER, WHICH IS ABOUT 1,000 TO 3,000 A THICK, BY A CHEMICAL VAPOR DEPOSITION METHOD AT A TEMPERATURE COMPRISED BETWEEN 600* AND 800*C WITH A SUFFICIENTLY LOW FLOW RATE OF SIH4 AND NH3 SO AS TO GIVE A GROWTH RATE OF THE SI3N3 LAYER COMPRISED BETWEEN ABOUT 10 A/MIN AND 100 A/MIN, AT LEAST PARTLY ON A SURFACE OF SAID SUBSTRATE; C. DEPOSITING A PHOSPHOSILICATE GLASS LAYER, WHICH IS ABOUT 2,000 TO ABOUT 6,000 A THICK AND IN WHICH THE ATOMIC PERCENT RATIO OF P2O5 TO SIO2 IS ABOUT 1 TO ABOUT 10%, ON SAID SI3N4 LAYER, COVERING SUBSTANTIALLY THE WHOLE OUTER SURFACE OF SAID SI3N4 LAYER; D. REMOVING AT LEAST A PART OF THE DOUBLE LAYER CONSISTING OF SAID SI3N4 LAYER AND SAID PHOSPHOSILICATE GLASS LAYER BY PHOTOETCHING TO THEREBY FORM A WINDOW FOR SLECTIVE DIFFUSION; E. DIFFUSING SECOND CONDUCTIVITY TYPE IMPURITY ATOMS THROUGH SAID WINDOW INTO SAID SUBSTRATE BY USING SAID DOUBLE LAYER AS A DIFFUSION MASK, THEREBY FORMING A DIFFUSION LAYER; F. DEPOSITING A METAL LAYER ON AT LEAST A PART OF THE SURFACE OF SAID DIFFUSION LAYER WITHIN SAID WINDOW, THEREBY FORMING AN ELECTRODE; AND G. DEPOSITING A METAL LAYER ON THE OTHER SIDE OF SAID SUBSTRATE, THEREBY FORMING ANOTHER ELECTRODE.
Claim 2
Independent Claim
235 words
A METHOD FOR MAKING III-V COMPOUND SEMICONDUCTOR DEVICES COMPRISING THE STEPS OF: A. PREPARING A SEMICONDUCTOR SUBSTRATE MADE OF A III-V COMPOUND OF FIRST CONDUCTIVITY TYPE; B. DEPOSITING AN SI3N4 LAYER, WHICH IS ABOUT 1,000 TO 3,000 A THICK, BY A CHEMICAL VAPOR DEPOSITION METHOD AT A TEMPERATURE COMPRISED BETWEEN 600* AND 800*C WITH A SUFFICIENTLY LOW FLOW RATE OF SIH4 AND NH3 SO AS TO GIVE A GROWTH RATE OF THE SI3N3 LAYER COMPRISED BETWEEN ABOUT 10 A/MIN AND 100 A/MIN, AT LEAST PARTLY ON A SURFACE OF SAID SUBSTRATE; C. DEPOSITING A PHOSPHOSILICATE GLASS LAYER, WHICH IS ABOUT 2,000 TO ABOUT 6,000 A THICK AND IN WHICH THE ATOMIC PERCENT RATIO OF P2O5 TO SIO2 IS ABOUT 1 TO ABOUT 10%, ON SAID SI3N4 LAYER, COVERING SUBSTANTIALLY THE WHOLE OUTER SURFACE OF SAID SI3N4 LAYER; D. REMOVING AT LEAST A PART OF THE DOUBLE LAYER CONSISTING OF SAID SI3N4 LAYER AND SAID PHOSPHOSILICATE GLASS LAYER BY PHOTOETCHING TO THEREBY FORM A WINDOW FOR SLECTIVE DIFFUSION; E. DIFFUSING SECOND CONDUCTIVITY TYPE IMPURITY ATOMS THROUGH SAID WINDOW INTO SAID SUBSTRATE BY USING SAID DOUBLE LAYER AS A DIFFUSION MASK, THEREBY FORMING A DIFFUSION LAYER; F. DEPOSITING A METAL LAYER ON AT LEAST A PART OF THE SURFACE OF SAID DIFFUSION LAYER WITHIN SAID WINDOW, THEREBY FORMING AN ELECTRODE; AND G. DEPOSITING A METAL LAYER ON THE OTHER SIDE OF SAID SUBSTRATE, THEREBY FORMING ANOTHER ELECTRODE.
Claim 3
Dependent Claim
28 words
A method for making a III-V compound semiconductor device according to claim 1, which said semiconductor substrate is of n-type and said diffused impurity atoms are of p-type.
Claim 4
Dependent Claim
25 words
A method for making a III-V compound semiconductor device according to claim 2, wherein said substrate is made of a mixed crystal of III-V compounds.
Claim 5
Dependent Claim
22 words
A method for making a III-V compound semiconductor device according to claim 3, wherein said substrate comprises P as a constituent element.
References Cited (Backward Citations)
US3580745A
Cited
US3629018A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-01-20 | 1978-07-22 | 1979-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-20 | 1982-07-22 | 1983-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-20 | 1986-07-22 | 1987-01-21 | $7700.00 | Window Closed / Lapsed |