US5149978A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for measuring grain sizes in metalized layers
Assignee: Therma Wave Inc
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Filing: 1990-12-07
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Granted: 1992-09-22
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Expires: 2010-12-07
Abstract
Abstract An apparatus (10) is disclosed for evaluating the size of grains in a metalized layer on a semiconductor sample (12). The apparatus includes a laser (20) for generating a probe beam (22). The probe beam is focused to a diameter of about one micron and scanned over the surface of the sample. Variations in the power of the specularly reflected beam are measured. In one aspect of the subject invention, the spacing between minima in the reflectivity signal is used to give a direct measurement of average grain size. The depth of the minima can be used to derive a distribution of the grain size. For very small grains, a statistical evaluation of the reflectivity signal is performed to derive grain size.
Inventors
- 👤 Jon Opsal
- 👤 Allan Rosencwaig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:44
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/55; G01N2021/555; G01N2021/559; G01N21/84; G01N21/8422; G01N2021/8427
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
128 words
An apparatus for evaluating grain sizes on the surface of the sample, wherein the grains have irregular shapes, said apparatus comprising: means for generating a probe beam; means for scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; means for measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and processor means for evaluating the sizes of the grains on the sample surface based on the probe beam power measurements, said processor means functioning to determine the average distance on the sample between locations where the power measurement drops below a predetermined threshold level to derive the average grain size.
Claim 2
Independent Claim
128 words
An apparatus for evaluating grain sizes on the surface of the sample, wherein the grains have irregular shapes, said apparatus comprising: means for generating a probe beam; means for scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; means for measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and processor means for evaluating the sizes of the grains on the sample surface based on the probe beam power measurements, said processor means functioning to determine the average distance on the sample between locations where the power measurement drops below a predetermined threshold level to derive the average grain size.
Claim 3
Dependent Claim
31 words
An apparatus as recited in claim 1 further including a means for focusing the probe beam on the surface of the sample to a diameter on the order of one micron.
Claim 4
Independent Claim
126 words
An apparatus for evaluating the distribution of grain sizes on the surface of the sample, wherein the grains have irregular shapes comprising: means for generating a probe beam; means for scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; means for measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and processor means for evaluating the distribution of grain size on the sample surface based on a determination of the number of times the minima of the probe beam power measurements fall below a predetermined threshold level in combination with a determination of the depth of these minima.
Claim 5
Independent Claim
126 words
An apparatus for evaluating the distribution of grain sizes on the surface of the sample, wherein the grains have irregular shapes comprising: means for generating a probe beam; means for scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; means for measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and processor means for evaluating the distribution of grain size on the sample surface based on a determination of the number of times the minima of the probe beam power measurements fall below a predetermined threshold level in combination with a determination of the depth of these minima.
Claim 6
Dependent Claim
26 words
An apparatus as recited in claim 3 wherein the processor means derives the distribution of grain sizes by analyzing the distribution of depth of the minima.
Claim 7
Dependent Claim
31 words
An apparatus as recited in claim 3 further including a means for focusing the probe beam on the surface of the sample to a diameter on the order of one micron.
Claim 8
Independent Claim
126 words
An apparatus for evaluating grain sizes on the surface of the sample, wherein the grains have irregular shapes, said apparatus comprising: means for generating a probe beam; means for focusing the probe beam onto the surface of the sample to diameter on the order of one micron; means for scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; means for measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and processor means for evaluating the average size of the grains on the sample surface based on a statistical analysis of the variations in the probe beam power measurements.
Claim 9
Independent Claim
126 words
An apparatus for evaluating grain sizes on the surface of the sample, wherein the grains have irregular shapes, said apparatus comprising: means for generating a probe beam; means for focusing the probe beam onto the surface of the sample to diameter on the order of one micron; means for scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; means for measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and processor means for evaluating the average size of the grains on the sample surface based on a statistical analysis of the variations in the probe beam power measurements.
Claim 10
Dependent Claim
23 words
An apparatus as recited in claim 6 wherein said processor means functions to calculate the standard deviation of the probe beam power measurements.
Claim 11
Dependent Claim
37 words
An apparatus as recited in claim 6 wherein the variations in the probe beam power measurements are compared with variations measured on test pieces having a known grain size to determine the grain size of the sample.
Claim 12
Independent Claim
118 words
A method for evaluating grain sizes on the surface of the sample, wherein the grains have irregular shapes, said method comprising the steps of: generating a probe beam; scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and evaluating the sizes of the grains on the sample surface based on the probe beam power measurements by determining the average distance on the sample between locations where the power measurement drops below a predetermined threshold level to derive the average grain size.
Claim 13
Independent Claim
118 words
A method for evaluating grain sizes on the surface of the sample, wherein the grains have irregular shapes, said method comprising the steps of: generating a probe beam; scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and evaluating the sizes of the grains on the sample surface based on the probe beam power measurements by determining the average distance on the sample between locations where the power measurement drops below a predetermined threshold level to derive the average grain size.
Claim 14
Dependent Claim
31 words
A method as recited in claim 9 further including the step of focusing the probe beam on the surface of the sample to a diameter on the order of one micron.
Claim 15
Independent Claim
122 words
A method for evaluating the distribution of grain sizes on the surface of the sample, wherein the grains have irregular shapes, said method comprising the steps of: generating a probe beam; scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and evaluating the distribution of grain size on the sample surface based on a determination of the number of times the minima of the probe beam power measurements fall below a predetermined threshold level in combination with a determination of the depth of these minima.
Claim 16
Independent Claim
122 words
A method for evaluating the distribution of grain sizes on the surface of the sample, wherein the grains have irregular shapes, said method comprising the steps of: generating a probe beam; scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and evaluating the distribution of grain size on the sample surface based on a determination of the number of times the minima of the probe beam power measurements fall below a predetermined threshold level in combination with a determination of the depth of these minima.
Claim 17
Dependent Claim
24 words
A method as recited in claim 11 wherein the distribution of grain sizes is derived by analyzing the distribution of depth of the minima.
Claim 18
Dependent Claim
31 words
A method as recited in claim 11 further including the step of focusing the probe beam on the surface of the sample to a diameter on the order of one micron.
Claim 19
Independent Claim
115 words
A method for evaluating grain sizes on the surface of the sample, wherein the grains have irregular shapes, said method comprising: generating a probe beam; focusing the probe beam onto the surface of the sample to diameter on the order of one micron; scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and evaluating the average size of the grains on the sample surface based on a statistical analysis of the variations in the probe beam power measurements.
Claim 20
Independent Claim
115 words
A method for evaluating grain sizes on the surface of the sample, wherein the grains have irregular shapes, said method comprising: generating a probe beam; focusing the probe beam onto the surface of the sample to diameter on the order of one micron; scanning the probe beam with respect to the surface of the sample an amount sufficient to cross a plurality of grain boundaries; measuring the power of the reflected probe beam as a function of the position of the probe beam on the surface of the sample; and evaluating the average size of the grains on the sample surface based on a statistical analysis of the variations in the probe beam power measurements.
Claim 21
Dependent Claim
25 words
A method as recited in claim 14 wherein said evaluation step includes the step of calculating the standard deviation of the probe beam power measurements.
Claim 22
Dependent Claim
37 words
A method as recited in claim 14 wherein the variations in the probe beam power measurements are compared with variations measured on test pieces having a known grain size to determine the grain size of the sample.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-09-22 | 1996-03-23 | 1996-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-22 | 2000-03-23 | 2000-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-22 | 2004-03-23 | 2004-09-22 | $7700.00 | Window Closed / Lapsed |