Patent US5389786A successfully refreshed from Google Patents.
US5389786A
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Method of quantitative determination of defect concentration on surfaces
Assignee: Nagoya University
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Filing: 1993-04-15
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Granted: 1995-02-14
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Expires: 2013-04-15
Abstract
Abstract The ablation threshold of a laser fluence with respect to the surface of a sample manufactured in a high vacuum chamber is determined by using the sample. The quantity of vacancy-type defects is determined by radiating a laser beam having a fluence slightly higher than the ablation threshold on the surface. At the same time, the quantities of adatom-type and kink-type defects are determined by radiating a pulsed laser beam having a fluence slightly lower than the ablation threshold on the surface repeatedly to obtain the relation between an emission yield and the number of laser pulses. The quantity of the adatom-type defects is obtained by determining the area (total quantity of emitted atoms) of a rapidly decreasing portion of the relation. The quantity of kink-type defects is obtained by determining a magnitude of an emission yield of a slowly decreasing portion of the relation.
Inventors
- 👤 Noriaki Itoh
- 👤 Yasuo Nakai
- 👤 Ken Hattori
- 👤 Akiko Okano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:55
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/71; G01N21/718
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
194 words
A method of quantitative determination of defect concentration on surfaces, comprising the steps of: determining an ablation threshold of a laser fluence with respect to a surface of a sample, manufactured in a high vacuum chamber; and determining a quantity of vacancy-type defects by radiating a laser beam having a fluence slightly higher than the ablation threshold on the surface and measuring a first emission yield Y 1 , corresponding to the quantity of vacancy-type defects, and determining respective quantities of adatom-type and kink-type defects by radiating a pulsed laser beam having a fluence slightly lower than the ablation threshold on the surface of the sample repeatedly to obtain a graph plotting the relationship between a second emission yield Y 2 , corresponding to the quantities of adatom-type and kink-type defects, and the number of laser pulses, the quantity of the adatom-type defects being obtained by determining an area under a first portion of the graph, and the quantity of kink-type defects being obtained by determining a magnitude of the second emission yield Y 2 of a second portion of the graph, the first portion having a steeper negative slope than the second portion.
Claim 2
Independent Claim
194 words
A method of quantitative determination of defect concentration on surfaces, comprising the steps of: determining an ablation threshold of a laser fluence with respect to a surface of a sample, manufactured in a high vacuum chamber; and determining a quantity of vacancy-type defects by radiating a laser beam having a fluence slightly higher than the ablation threshold on the surface and measuring a first emission yield Y 1 , corresponding to the quantity of vacancy-type defects, and determining respective quantities of adatom-type and kink-type defects by radiating a pulsed laser beam having a fluence slightly lower than the ablation threshold on the surface of the sample repeatedly to obtain a graph plotting the relationship between a second emission yield Y 2 , corresponding to the quantities of adatom-type and kink-type defects, and the number of laser pulses, the quantity of the adatom-type defects being obtained by determining an area under a first portion of the graph, and the quantity of kink-type defects being obtained by determining a magnitude of the second emission yield Y 2 of a second portion of the graph, the first portion having a steeper negative slope than the second portion.
Claim 3
Dependent Claim
44 words
The method according to claim 1, wherein the quantity of vacancy-type defects is obtained by using the equation Y.sub.1 =qφ.sup.n N where q is an emission coefficient, φ is the laser fluence, n is an exponent, and N is the quantity of vacancy-type defects.
Claim 4
Dependent Claim
44 words
The method according to claim 1, wherein the quantity of kink-type defects is obtained by using the equation Y.sub.2 =qφ.sup.n N wherein q is an emission coefficient, φ is the laser fluence, n is an exponent, and N is the quantity of kink-type defects.
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) | 1998-02-13 | 1998-08-15 | 1999-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-13 | 2002-08-15 | 2003-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-13 | 2006-08-15 | 2007-02-14 | $7700.00 | Window Closed / Lapsed |