Patent US3928095A successfully refreshed from Google Patents.
US3928095A
Expired / Lapsed
US
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Semiconductor device and process for manufacturing same
Assignee: Suwa Seikosha KK
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Filing: 1974-07-26
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Granted: 1975-12-23
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Expires: 1994-07-26
Abstract
Abstract A silicon substrate is coated with a layer of polycrystalline silicon containing a selected quantity of dopant. The combination is heated to cause diffusion of the dopant from the film into the substrate. The polycrystalline coating of silicon may contain more than one dopant. The product is a semiconductor device including crystalline silicon doped to a concentration of 1014 to 1017 protected by a layer of polycrystalline silicon.
Inventors
- 👤 Hiroshi Harigaya
- 👤 Masao Kanai
- 👤 Toshio Kano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:25
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P14/6309; H10D; H10D62/00; H10D62/80; H10D62/83; H10D64/00; H10D64/60; H10D64/62; H10P14/6322; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/1414; H10P32/17; H10P32/171; H10W; H10W20/00; H10W20/40; Y; Y10; Y10S; Y10S148/00; Y10S148/117; Y10S148/118; Y10S148/122; Y10S148/151; Y10S438/00; Y10S438/914; Y10S438/92
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
180 words
THE IMPROVEMENT IN A PROCESS FOR THE FORMATION ON A SILICON SUBSTRATE OF A SURFACE REGION CONTAINING 10**14 -10**17 IMPURITY ATOMS/CM3 INRRODUCED BY DIFFUSION AND TO WHICH RELIABLE AHMIC METALLIC CONTACT CAN BE MADE, WHEREIN SAID IMPROVEMENT COMPRISES THE STEPS OF HOLDING A SILICON SUBSTRATE HAVING AN APERTURED FILM OF SIO2 THEREON AT A TEMPERATURE OF 500 - 700*C FOR A PERIOD BETWEEN 2 AND 40 MINUTES IN A FIRST ATMOSPHERE CONSISTING OF AN INERT GAS, SILANE AND A GASEOUS IMPURITY SOURCE TO FORM A LAYER OF POLYCRYSTALLINE SILICON CONTAINING THE IMPURITY FROM SAID SOURCE ON SAID SUBSTRATE AND APERTURED FILM, SAID POLYCRYSTALLINE SI LAYER CONTAINING 10**14 -10**17 IMPURITY ATOMS/CM3, REPLACING SAID FIRST ATMOSPHERE WITH A SECOND ATMOSPHERE INCLUDING OXYGEN AND FREE OF SILANE AND SAID IMPURITY SOURCE, AND HOLDING SAID SUBSTRATE AT A TEMPERATURE BETWEEN 900* AND 1250*C FOR A PERIOD BETWEEN 5 AND 60 MINUTES TO EFFECT CONCURRENT DIFFFUSION OF SAID IMPURITY FROM SAID POLYCRYSTALLINE SILICON INTO SAID SUBSTRATE AT THE APERTURE IN SAID FILM AND OXIDATION OF SAID POLYCRYSTALLINE SILICON LAYER TO FORM SIO2 CONTAINING SAID IMPURITY.
Claim 2
Dependent Claim
180 words
THE IMPROVEMENT IN A PROCESS FOR THE FORMATION ON A SILICON SUBSTRATE OF A SURFACE REGION CONTAINING 10**14 -10**17 IMPURITY ATOMS/CM3 INRRODUCED BY DIFFUSION AND TO WHICH RELIABLE AHMIC METALLIC CONTACT CAN BE MADE, WHEREIN SAID IMPROVEMENT COMPRISES THE STEPS OF HOLDING A SILICON SUBSTRATE HAVING AN APERTURED FILM OF SIO2 THEREON AT A TEMPERATURE OF 500 - 700*C FOR A PERIOD BETWEEN 2 AND 40 MINUTES IN A FIRST ATMOSPHERE CONSISTING OF AN INERT GAS, SILANE AND A GASEOUS IMPURITY SOURCE TO FORM A LAYER OF POLYCRYSTALLINE SILICON CONTAINING THE IMPURITY FROM SAID SOURCE ON SAID SUBSTRATE AND APERTURED FILM, SAID POLYCRYSTALLINE SI LAYER CONTAINING 10**14 -10**17 IMPURITY ATOMS/CM3, REPLACING SAID FIRST ATMOSPHERE WITH A SECOND ATMOSPHERE INCLUDING OXYGEN AND FREE OF SILANE AND SAID IMPURITY SOURCE, AND HOLDING SAID SUBSTRATE AT A TEMPERATURE BETWEEN 900* AND 1250*C FOR A PERIOD BETWEEN 5 AND 60 MINUTES TO EFFECT CONCURRENT DIFFFUSION OF SAID IMPURITY FROM SAID POLYCRYSTALLINE SILICON INTO SAID SUBSTRATE AT THE APERTURE IN SAID FILM AND OXIDATION OF SAID POLYCRYSTALLINE SILICON LAYER TO FORM SIO2 CONTAINING SAID IMPURITY.
Claim 3
Dependent Claim
19 words
The improvement as defined in claim 1 wherein said Si substrate is n-type and said impurity source is B2H6.
Claim 4
Dependent Claim
19 words
The improvement as defined in claim 1 wherein said Si substrate is p-type and said impurity source is PH3.
Claim 5
Dependent Claim
44 words
The improvement as defined in claim 1 wherein said first atmosphere is introduced in a ratio corresponding approximately to 12 liters of inert gas, 2%, SiH4 in 0.5 liter of inert gas and 5 ppm of B2H6 in 0.005 -5 liters of inert gas.
Claim 6
Dependent Claim
45 words
The improvement as defined in claim 1 wherein said first atmosphere is introduced in a ratio corresponding approximately to 12 liters of inert gas, 2% SiH4 in 0.5 liter of inert gas and 10 ppm of PH3 in 0.005 - 5 liters of inert gas.
Claim 7
Dependent Claim
43 words
The improvement as defined in claim 1, further comprising the steps of etching an opening through said layer of impurity containing SiO2 to the impurity-diffused region in said substrate, and depositing metal in a controlled pattern to make contact with said impurity-diffused region.
Claim 8
Dependent Claim
62 words
The improvement as defined in claim 1, further comprising the steps of etching away said film and layer of impurity containing SiO2 from said substrate, depositing a new layer of SiO2 over said substrate, etching an opening through said new layer at the impurity-diffused region in said substrate and depositing metal in a controlled pattern to make contact with said impurity-diffused region.
Claim 9
Dependent Claim
43 words
The improvement as defined in claim 1 wherein said first atmosphere is introduced in a ratio corresponding approximately to 12 liters of inert gas, 2% SiH4 in 0.5 liter of inert gas and 5 ppm of B2H6 in 0.1 liter of inert gas.
Claim 10
Dependent Claim
43 words
The improvement as defined in claim 1 wherein said first atmosphere is introduced in a ratio corresponding approximately to 12 liters of inert gas, 2% SiH4 in 0.5 liter of inert gas and 10 ppm of PH3 in 0.1 liter of inert gas.
Claim 11
Dependent Claim
77 words
A silicon substrate having a surface region containing a concentration of impurity atoms of 1014 -1017/cm3, the distribution of impurity atoms with depth in said substrate being characteristic of that obtained by diffusion at a temperature between 900* and 1250*C from a polycrystalline silicon layer on said substrate, said silicon substrate having thereon a layer of silicon dioxide having a gap in registry with said surface region, and a metallic electrode making contact with said surface region.
Claim 12
Dependent Claim
77 words
A silicon substrate having a surface region containing a concentration of impurity atoms of 1014 -1017/cm3, the distribution of impurity atoms with depth in said substrate being characteristic of that obtained by diffusion at a temperature between 900* and 1250*C from a polycrystalline silicon layer on said substrate, said silicon substrate having thereon a layer of silicon dioxide having a gap in registry with said surface region, and a metallic electrode making contact with said surface region.
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) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |