US4259574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microanalysis by pulse laser emission spectroscopy
Assignee: International Business Machines Corp
•
Filing: 1979-11-06
•
Granted: 1981-03-31
•
Expires: 1999-11-06
Abstract
Abstract A system for detecting and identifying the composition of a material, such as semiconductor wafers and chips, subject to one or more stages of processing. The material is laser irradiated to induce molecular fluorescence with means to detect the decay rate of the fluorescence. The decay rate is then compared with a decay record of fluorescence of acceptable modifications of the material, inclusive of amalgamated contaminants or impurities (e.g. doped regions) to determine the state of the modification of the material.
Inventors
- 👤 Timothy W. Carr
- 👤 Howard A. Froot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:38
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6408
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
106 words
System for identifying the composition of a material subjected to at least one stage of processing in a manufacturing line, comprising: means for providing a record of known decay rates of the molecular fluorescence, from the excited to a lower energy state, of said material of acceptable modification thereof at the end of each stage of processing, means at the end of each state of processing for laser irradiating said material to induce molecular fluorescence thereof, means for detecting the decay rate of said induced fluorescence, and means for comparing said detected decay rate with said record to determine the state of modification of each material.
Claim 2
Dependent Claim
106 words
System for identifying the composition of a material subjected to at least one stage of processing in a manufacturing line, comprising: means for providing a record of known decay rates of the molecular fluorescence, from the excited to a lower energy state, of said material of acceptable modification thereof at the end of each stage of processing, means at the end of each state of processing for laser irradiating said material to induce molecular fluorescence thereof, means for detecting the decay rate of said induced fluorescence, and means for comparing said detected decay rate with said record to determine the state of modification of each material.
Claim 3
Dependent Claim
13 words
The system of claim 1 wherein said irradiation is at a pulsed rate.
Claim 4
Dependent Claim
17 words
The system of claim 1 wherein said irradiation is pulsed at a 10 -9 second pulse width.
Claim 5
Dependent Claim
23 words
The system of claim 1 wherein said irradiation is with ultraviolet-visible light with energies ranging from about 6 ev. to about 2 ev.
Claim 6
Dependent Claim
13 words
The system of claim 4 wherein said irradiation is at a pulsed rate.
Claim 7
Dependent Claim
17 words
The system of claim 4 wherein said irradiation is pulsed at a 10 -9 second pulse width.
Claim 8
Dependent Claim
14 words
The system of claim 1 wherein said system is off-line of said manufacturing line.
Claim 9
Dependent Claim
13 words
The system of claim 1 wherein said material is a silicon semiconductor substrate.
Claim 10
Dependent Claim
13 words
The system of claim 7 wherein said material is a silicon semiconductor substrate.
Claim 11
Independent Claim
106 words
A system for identifying the composition of a material subjected through various stages of processing in a manufacturing line, comprising: means for providing a record of known decay rates of the molecular fluorescence from the excited to lower energy states of said material, by irradiation thereof, of anticipated chemical modifications inclusive of amalgamated contaminations thereof through said processing stages, means associated with said processing stages for laser irradiation of said material to induce molecular fluorescence thereof, means for detecting the decay rate of said induced fluorescence, and means for comparing said detected decay rate with said record to determine the state of modification of said material.
Claim 12
Independent Claim
106 words
A system for identifying the composition of a material subjected through various stages of processing in a manufacturing line, comprising: means for providing a record of known decay rates of the molecular fluorescence from the excited to lower energy states of said material, by irradiation thereof, of anticipated chemical modifications inclusive of amalgamated contaminations thereof through said processing stages, means associated with said processing stages for laser irradiation of said material to induce molecular fluorescence thereof, means for detecting the decay rate of said induced fluorescence, and means for comparing said detected decay rate with said record to determine the state of modification of said material.
Claim 13
Dependent Claim
13 words
The system of claim 10 wherein said irradiation is at a pulsed rate.
Claim 14
Dependent Claim
17 words
The system of claim 10 wherein said irradiation is pulsed at a 10 -9 second pulse width.
Claim 15
Dependent Claim
23 words
The system of claim 10 wherein said irradiation is with ultraviolet-visible light with energies ranging from about 6 ev. to about 2 ev.
Claim 16
Dependent Claim
13 words
The system of claim 13 wherein said irradiation is at a pulsed rate.
Claim 17
Dependent Claim
17 words
The system of claim 13 wherein said irradiation is pulsed at a 10 -9 second pulse width.
Claim 18
Dependent Claim
13 words
The system of claim 10 wherein said material is a silicon semiconductor substrate.
Claim 19
Dependent Claim
14 words
The system of claim 10 wherein said system is off-line of said manufacturing line.
Claim 20
Dependent Claim
13 words
The system of claim 17 wherein said material is a silicon semiconductor substrate.
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) | 1984-03-30 | 1984-09-29 | 1985-03-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-30 | 1988-09-29 | 1989-03-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-30 | 1992-09-29 | 1993-03-31 | $7700.00 | Window Closed / Lapsed |