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US6118533A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for measuring the concentration of ions implanted in semiconductor materials

Assignee: Advanced Metrology Systems LLC
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Filing: 1997-09-10
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Granted: 2000-09-12
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Expires: 2017-09-10
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Abstract

Abstract A method and apparatus that determines a concentration of ions implanted in a material is described. The method includes the steps of: 1) generating at least two excitation laser sub-pulses and a probe pulse from a single pulse emitted from a laser; 2) irradiating a region of the material with a grating pattern formed by overlapping at least two excitation laser sub-pulses to initiate a time-dependent response in the region; 3) diffracting a probe laser pulse off the region to generate at least one time-dependent signal beam; 4) detecting at least one time-dependent signal beam to generate a signal waveform; and 5) processing the signal waveform to determine the concentration of ions implanted in the material.

Inventors

  • 👤 Matthew J. Banet
  • 👤 John A. Rogers
  • 👤 Martin Fuchs

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 21:31
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/1717; G01N21/41

Claims Analysis

Total Claims: 34
Claim 1
Independent Claim 106 words
A method for determining a concentration of ions implanted in a material, comprising the steps of: generating at least two excitation laser sub-pulses and a probe pulse from a single pulse emitted from a laser; irradiating a region of the material with a grating pattern, formed by overlapping the at least two excitation laser sub-pulses to initiate a time-dependent response in the region; diffracting the probe pulse off the region to generate at least one time-dependent signal beam; detecting the at least one time-dependent signal beam to generate a signal waveform; and processing the signal waveform to determine the concentration of ions implanted in the material.
Claim 2
Independent Claim 106 words
A method for determining a concentration of ions implanted in a material, comprising the steps of: generating at least two excitation laser sub-pulses and a probe pulse from a single pulse emitted from a laser; irradiating a region of the material with a grating pattern, formed by overlapping the at least two excitation laser sub-pulses to initiate a time-dependent response in the region; diffracting the probe pulse off the region to generate at least one time-dependent signal beam; detecting the at least one time-dependent signal beam to generate a signal waveform; and processing the signal waveform to determine the concentration of ions implanted in the material.
Claim 3
Dependent Claim 32 words
The method of claim 1, wherein the processing step includes determining a property of the signal waveform and then analyzing the property to determine the concentration of ions implanted in the sample.
Claim 4
Dependent Claim 15 words
The method of claim 2, wherein the property is an amplitude of the signal waveform.
Claim 5
Dependent Claim 21 words
The method of claim 2, wherein the processing step further includes comparing the property of the signal waveform to a database.
Claim 6
Dependent Claim 46 words
The method of claim 4, wherein the comparing step further includes comparing the property of the signal waveform to a database that correlates properties of previously measured signal waveforms to concentrations of ions implanted in materials to determine the concentration of ions implanted in the material.
Claim 7
Dependent Claim 15 words
The method of claim 5, wherein the property of the signal waveform is an amplitude.
Claim 8
Dependent Claim 28 words
The method of claim 1, wherein the processing step further includes analyzing the property with a mathematical algorithm to determine the concentration of ions implanted in the material.
Claim 9
Dependent Claim 41 words
The method of claim 1, wherein the processing step includes digitizing the signal waveform to generate a data set and then determining an amplitude of the signal waveform at a point in time by selecting a value from the data set.
Claim 10
Dependent Claim 21 words
The method of claim 1, wherein the processing step includes determining an area covered by a plot of the signal waveform.
Claim 11
Dependent Claim 17 words
The method of claim 9, wherein the processing step further includes comparing the area to a database.
Claim 12
Dependent Claim 40 words
The method of claim 10, wherein the comparing step further includes comparing the area to a database that correlates the area with the concentration of ions implanted in a material to determine the concentration of ions implanted in the material.
Claim 13
Dependent Claim 10 words
The method of claim 1, wherein the material contains silicon.
Claim 14
Dependent Claim 12 words
The method of claim 12, wherein the material is a polysilicon film.
Claim 15
Dependent Claim 12 words
The method of claim 12, wherein the material is a silicon wafer.
Claim 16
Dependent Claim 31 words
The method of claim 1, wherein an ion implanted in the material is an ion of an atom selected from the group consisting of arsenic, argon, boron, oxygen and phosphorous atoms.
Claim 17
Independent Claim 114 words
A method for determining a concentration of ions implanted in a material, comprising the steps of: generating a single laser pulse; passing the single laser pulse through a phase mask to form at least two excitation sub-pulses and at least one probe pulse; irradiating a region of the material with a grating pattern, formed by overlapping the at least two excitation least sub-pulses to initiate a time-dependent response in the region; diffracting the probe pulse off the region to generate at least one time-dependent signal beam; detecting the at least one time-dependent signal beam to generate a signal waveform; and processing the signal waveform to determine the concentration of ions implanted in the material.
Claim 18
Independent Claim 114 words
A method for determining a concentration of ions implanted in a material, comprising the steps of: generating a single laser pulse; passing the single laser pulse through a phase mask to form at least two excitation sub-pulses and at least one probe pulse; irradiating a region of the material with a grating pattern, formed by overlapping the at least two excitation least sub-pulses to initiate a time-dependent response in the region; diffracting the probe pulse off the region to generate at least one time-dependent signal beam; detecting the at least one time-dependent signal beam to generate a signal waveform; and processing the signal waveform to determine the concentration of ions implanted in the material.
Claim 19
Dependent Claim 32 words
The method of claim 1, wherein the processing step includes determining a property of the signal waveform and then processing the property to determine the concentration of ions implanted in the sample.
Claim 20
Dependent Claim 15 words
The method of claim 17, wherein the property is an amplitude of the signal waveform.
Claim 21
Dependent Claim 21 words
The method of claim 17, wherein the processing step further includes comparing the property of the signal waveform to a database.
Claim 22
Dependent Claim 46 words
The method of claim 19, wherein the comparing step further includes comparing the property of the signal waveform to a database that correlates properties of previously measured signal waveforms to concentrations of ions implanted in materials to determine the concentration of ions implanted in the material.
Claim 23
Independent Claim 135 words
An apparatus for determining a concentration of ions implanted in a semiconduting material, comprising: a laser for generating an excitation laser pulse and a probe laser pulse from a single laser pulse; a first beam-delivery system for separating the excitation laser pulse into at least two excitation sub-pulses and then irradiating a region of the material with a grating pattern formed by overlapping the at least two excitation sub-pulses to initiate a time-dependent response in the region; a second beam-delivery system for delivering the probe pulse to the sample such that the probe pulse diffracts off the region to generate a time-dependent signal beam; a photodectector for detecting the time-dependent signal bean to generate a signal waveform; and a processor for processing the signal waveform to determine the concentration of ions implanted in the material.
Claim 24
Independent Claim 135 words
An apparatus for determining a concentration of ions implanted in a semiconduting material, comprising: a laser for generating an excitation laser pulse and a probe laser pulse from a single laser pulse; a first beam-delivery system for separating the excitation laser pulse into at least two excitation sub-pulses and then irradiating a region of the material with a grating pattern formed by overlapping the at least two excitation sub-pulses to initiate a time-dependent response in the region; a second beam-delivery system for delivering the probe pulse to the sample such that the probe pulse diffracts off the region to generate a time-dependent signal beam; a photodectector for detecting the time-dependent signal bean to generate a signal waveform; and a processor for processing the signal waveform to determine the concentration of ions implanted in the material.
Claim 25
Dependent Claim 25 words
The apparatus of claim 21, wherein the first beam-delivery system includes a phase mask that separates the excitation laser pulse into at least two sub-pulses.
Claim 26
Dependent Claim 17 words
The apparatus of claim 21, wherein the diffracting mask is a phase mask or an amplitude mask.
Claim 27
Dependent Claim 36 words
The apparatus of claim 21, wherein the processor is a computer that analyzes an amplitude of the signal waveform and compares the amplitude to a database to determine the concentration of ions implanted in the material.
Claim 28
Dependent Claim 37 words
The apparatus of claim 21, wherein the processor is a computer that determines an area covered by the signal waveform and compares the area to a database to determine the concentration of ions implanted in the material.
Claim 29
Dependent Claim 20 words
The apparatus of claim 21, wherein the excitation sub-pulses and the probe pulse are overlapped in time in the region.
Claim 30
Dependent Claim 16 words
The apparatus of claim 21, wherein the photodetector has a bandwidth of less than 1 MHz.
Claim 31
Independent Claim 126 words
An apparatus for determining a concentration of ions implanted in a semiconducting material, comprising: a laser for generating a single laser pulse; a beam-delivery system comprising a phase mask that separates the single laser pulse into at least two excitation sub-pulses and a probe pulse, and a lens that focuses and overlaps at least two excitation sub-pulses and the probe pulse on the sample so that the excitation sub-pulses form a grating pattern that initiates a time-dependent response in the region and the probe pulse diffracts off the region to generate a time-dependent signal beam; a photodetector for detecting the time-dependent signal beam to generate a signal waveform; and a processor for processing the signal waveform to determine the concentration of ions implanted in the material.
Claim 32
Independent Claim 126 words
An apparatus for determining a concentration of ions implanted in a semiconducting material, comprising: a laser for generating a single laser pulse; a beam-delivery system comprising a phase mask that separates the single laser pulse into at least two excitation sub-pulses and a probe pulse, and a lens that focuses and overlaps at least two excitation sub-pulses and the probe pulse on the sample so that the excitation sub-pulses form a grating pattern that initiates a time-dependent response in the region and the probe pulse diffracts off the region to generate a time-dependent signal beam; a photodetector for detecting the time-dependent signal beam to generate a signal waveform; and a processor for processing the signal waveform to determine the concentration of ions implanted in the material.
Claim 33
Dependent Claim 17 words
The apparatus of claim 28, wherein the diffracting mask is a phase mask or an amplitude mask.
Claim 34
Dependent Claim 36 words
The apparatus of claim 28, wherein the processor is a computer that analyzes an amplitude of the signal waveform and compares the amplitude to a database to determine the concentration of ions implanted in the material.

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Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2003-09-12 2004-03-13 2004-09-12 $2000.00 Window Closed / Lapsed
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