US3723873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiation method for determining semiconductor stability and reliability
Assignee: Singer Co
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Filing: 1971-01-21
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Granted: 1973-03-27
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Expires: 1991-01-21
Abstract
Abstract A semiconductor wafer is tested for stability and reliability by subjecting preselected chips on the wafer to a predetermined dose of ionizing radiation and measuring the resulting change in electrical operating parameters of the preselected chips to obtain an indication of the general stability and reliability of the entire wafer being tested.
Inventors
- 👤 A Witteles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:11
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/26; G01R31/265
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
81 words
The method of determining the stability and reliability of semiconductor devices associated with a common structure or wafer comprising the steps of subjecting at least one semiconductor device from said wafer to a predetermined dose of ionizing radiation to cause a change in an electrical operating parameter of the device which is sensitive to the surface states of the device; and measuring the change in said parameter to provide an indication of the stability and reliability of the remaining semiconductor devices.
Claim 2
Independent Claim
81 words
The method of determining the stability and reliability of semiconductor devices associated with a common structure or wafer comprising the steps of subjecting at least one semiconductor device from said wafer to a predetermined dose of ionizing radiation to cause a change in an electrical operating parameter of the device which is sensitive to the surface states of the device; and measuring the change in said parameter to provide an indication of the stability and reliability of the remaining semiconductor devices.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein said predetermined dose of radiation is at least 50,000 rads.
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein said radiation is provided by an X-ray source.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein said radiation is provided by a gamma ray source.
Claim 6
Dependent Claim
15 words
The method of claim 1 wherein said radiation is provided by an alpha ray source.
Claim 7
Dependent Claim
38 words
The method of claim 1 wherein said semiconductor device is a Field effect semiconductor and the said electrical operating parameter is selected from the group comprising the threshold voltage and the drain to source current of the device.
Claim 8
Dependent Claim
39 words
The method of claim 1 wherein said semiconductor device is a bipolar semiconductor and the said electrical operating parameter is selected from the group comprising the current gain, the saturation collector-emitter voltage and the base-emitter voltage of the device.
Claim 9
Independent Claim
86 words
The method of testing semiconductor wafers having a plurality of semiconductor chips thereon for stability and reliability comprising the steps of subjecting a number of preselected chips on each wafer being tested to a predetermined dose of ionizing radiation to cause a change in an electrical operating parameter of each preselected chip which is sensitive to the surface states of the chip; and measuring the change in said parameter for each preselected chip to provide an indication of the stability and reliability of the entire wafer.
Claim 10
Independent Claim
86 words
The method of testing semiconductor wafers having a plurality of semiconductor chips thereon for stability and reliability comprising the steps of subjecting a number of preselected chips on each wafer being tested to a predetermined dose of ionizing radiation to cause a change in an electrical operating parameter of each preselected chip which is sensitive to the surface states of the chip; and measuring the change in said parameter for each preselected chip to provide an indication of the stability and reliability of the entire wafer.
Claim 11
Dependent Claim
20 words
The method of claim 8 wherein the predetermined dose of radiation for each preselected chip is at least 50,000 rads.
Claim 12
Dependent Claim
36 words
The method of claim 9 wherein the wafer being tested is placed on a programmed indexing machine for movement thereby and the preselected chips are sequentially irradiated by a well collimated beam of said ionizing radiation.
Claim 13
Dependent Claim
47 words
The method of claim 9 wherein a radiation shielding mask is placed over the wafer being tested, said mask having apertures formed therein corresponding to said preselected chips, and wherein the shielded wafer is subjected to said ionizing radiation, so that said preselected chips are simultaneously irradiated.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |