US4013485A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for eliminating undesirable charge centers in MIS devices
Assignee: International Business Machines Corp
•
Filing: 1976-04-29
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Granted: 1977-03-22
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Expires: 1996-04-29
Abstract
Abstract The electrical properties of MIS semiconductor devices, which have been damaged by radiation, are restored by treating the devices in a properly oriented RF field at low pressure.
Inventors
- 👤 Tso-Ping Ma
- 👤 William Hsioh-Lien Ma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:52
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/80; Y; Y10; Y10S; Y10S438/00; Y10S438/91
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
37 words
A process for restoring the electrical properties of radiation damaged semiconductor structures comprising treating the structures with a radio frequency field which is oriented substantially perpendicular to the structures in a substantially neutral atmosphere at reduced pressure.
Claim 2
Dependent Claim
37 words
A process for restoring the electrical properties of radiation damaged semiconductor structures comprising treating the structures with a radio frequency field which is oriented substantially perpendicular to the structures in a substantially neutral atmosphere at reduced pressure.
Claim 3
Dependent Claim
41 words
The process of claim 1 which employs a capacitively coupled RF field with a frequency in the range of about 3 to 30 MHz with a power source of 200 to 600 watts and the pressure is below about 300 microns.
Claim 4
Dependent Claim
96 words
A process for restoring the electrical properties of radiation damaged MIS structures formed on the surface of a silicon wafer comprising supporting said wafer by its edge in a chamber, reducing the pressure in said chamber to below about 300 microns, applying a capacitively coupled RF field to said chamber such that the electrical field direction is oriented substantially perpendicular to the surface of said wafer, for a time sufficient to restore the electrical properties of said MIS structures, removing said field and restoring said chamber to atmospheric pressure, and removing said wafer from said chamber.
Claim 5
Dependent Claim
96 words
A process for restoring the electrical properties of radiation damaged MIS structures formed on the surface of a silicon wafer comprising supporting said wafer by its edge in a chamber, reducing the pressure in said chamber to below about 300 microns, applying a capacitively coupled RF field to said chamber such that the electrical field direction is oriented substantially perpendicular to the surface of said wafer, for a time sufficient to restore the electrical properties of said MIS structures, removing said field and restoring said chamber to atmospheric pressure, and removing said wafer from said chamber.
Claim 6
Dependent Claim
69 words
The process of claim 3 wherein the pressure is about 10 microns, the frequency is in the range from about 3 to 30 MHz with a power source of about 200 to 600 watts, the time is from about 2 to 60 minutes and the heating effect of the RF field on the wafer does not heat the wafer to a temperature above about 340° C during the process.
Claim 7
Dependent Claim
18 words
The process of claim 4 wherein the MIS structures are aluminum-silicon nitride-silicon oxide-silicon capacitors and field effect transistors.
Claim 8
Dependent Claim
17 words
The process of claim 4 wherein the MIS structures are aluminum-silicon oxide-silicon capacitors and field effect transistors.
Claim 9
Dependent Claim
11 words
The process of claim 4 wherein the frequency is 13.46 MHz.
References Cited (Backward Citations)
US3533857A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-21 | 1980-09-20 | 1981-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-21 | 1984-09-20 | 1985-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-21 | 1988-09-20 | 1989-03-22 | $7700.00 | Window Closed / Lapsed |