US4331709A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of reducing density of fast surface states in MOS devices
Assignee: Siemens AG
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Filing: 1980-07-22
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Granted: 1982-05-25
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Expires: 2000-07-22
Abstract
Abstract Fast surface states in MOS devices, such as SCCDs, are reduced by depositing a relatively thin amorphous layer containing silicon and hydrogen onto the SiO 2 surface of such devices and annealing the resultant device in a non-oxidizing atmosphere for brief periods of time at a temperature in excess of the deposition temperature for the amorphous layer but below about 500° C. so that free valences at the Si-SiO 2 interface region are saturated with hydrogen. Surface state densities of about 4×10 8 cm -2 eV -1 and SCCDs having ε=1.10 -5 can be achieved via this process. The process is useful in producing SCCDs with low surface state densities and other MOS devices having low surface generated dark currents.
Inventors
- 👤 Lothar Risch
- 👤 Erich Pammer
- 👤 Karlheinz Friedrich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:38
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/68; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/01338; H10D64/0134; H10D64/60; H10D64/66; H10D64/68; H10D64/693; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6334; H10P14/6336; H10P14/66; H10P14/668; H10P14/6681; H10P14/6682; H10P95/00; H10P95/90; H10W; H10W74/00; H10W74/40; H10W74/43; H10W74/481; H10D64/01342; Y; Y10; Y10S; Y10S438/00; Y10S438/91
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
134 words
A process for reducing the density of fast surface states in MOS devices, such as surface-charge-coupled devices (SCCDs), comprising: providing a MOS device having a Si-SiO 2 interface region with the SiO 2 defining a free surface of such device and having electrodes therein; depositing a relatively thin amorphous layer comprised of silicon, hydrogen and nitrogen from a reaction gas comprised of silanium and a nitrogen-containing gas at a given deposition temperature onto said SiO 2 free surface of the device; and annealing the resultant structure in a non-oxidizing atmosphere for a relatively brief period of time at a temperature in excess of said given deposition temperature and below about 500° C. whereby free valences at the Si-SiO 2 interface region are saturated with hydrogen and the density of fast surface states is reduced.
Claim 2
Dependent Claim
134 words
A process for reducing the density of fast surface states in MOS devices, such as surface-charge-coupled devices (SCCDs), comprising: providing a MOS device having a Si-SiO 2 interface region with the SiO 2 defining a free surface of such device and having electrodes therein; depositing a relatively thin amorphous layer comprised of silicon, hydrogen and nitrogen from a reaction gas comprised of silanium and a nitrogen-containing gas at a given deposition temperature onto said SiO 2 free surface of the device; and annealing the resultant structure in a non-oxidizing atmosphere for a relatively brief period of time at a temperature in excess of said given deposition temperature and below about 500° C. whereby free valences at the Si-SiO 2 interface region are saturated with hydrogen and the density of fast surface states is reduced.
Claim 3
Dependent Claim
26 words
A process as defined in claim 1 wherein said nitrogen-containing gas is selected from the group consisting of N 2 , NH 3 and mixtures thereof.
Claim 4
Dependent Claim
23 words
A process as defined in claim 1 wherein the maximum atomic ratio of nitrogen to silicon in said amorphous layer is about 1.3.
References Cited (Backward Citations)
US4113514A
Cited
US4181751A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-24 | 1985-11-23 | 1986-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-24 | 1989-11-23 | 1990-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-24 | 1993-11-23 | 1994-05-25 | $7700.00 | Window Closed / Lapsed |