US4983039A
Expired / Lapsed
US
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Spectrometer
Assignee: Hitachi Ltd
•
Filing: 1989-06-22
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Granted: 1991-01-08
•
Expires: 2009-06-22
Abstract
Abstract A spectrometer is disclosed, in which plural entrance slits are mounted, and a reference light passing through one entrance slit and the light to be measured passing through the other entrance slit are simultaneously focused on a photo-sensitive surface of a detector through a diffraction grating and a focusing optical system, to measure the wavelength of the light to be measured precisely by using the reference light as a standard.
Inventors
- 👤 Tatsuo Harada
- 👤 Toshiei Kurosaki
- 👤 Toshiaki Kita
- 👤 Tsuneo Terasawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:50
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70483; G03F7/7055; G03F7/70575; G01; G01J; G01J3/00; G01J3/02; G01J3/04; G01J3/28; G01J9/00; H; H01; H01S; H01S3/00; H01S3/10; H01S3/13; H01S3/136; H01S3/137; G01J2003/047; G01J3/12; G01J3/18; G01J2003/1842; G01J2003/1847; G01J2003/2866; G01J3/0294; G01J3/1804; G01J3/2803; H01S3/14; H01S3/22; H01S3/223; H01S3/225
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
131 words
A spectrometer, comprising: a first entrance slit for passing a reference light beam therethrough; a second entrance slit for passing a light beam to be measured therethrough; a combination of a diffraction grating and a focusing optical system for reflecting and diffracting at least a spectral line of both the reference light beam passing through the first entrance slit and the light beam to be measured passing through the second entrance slit, to focus the spectral lines of the reflected and diffracted reference light beam and the reflected and diffracted light beam to be measured; and linear image detection means for measuring the wavelength of the focused spectral line light beam to be measured by using the wavelength of the focused spectral line of the reference light beam as a standard.
Claim 2
Dependent Claim
131 words
A spectrometer, comprising: a first entrance slit for passing a reference light beam therethrough; a second entrance slit for passing a light beam to be measured therethrough; a combination of a diffraction grating and a focusing optical system for reflecting and diffracting at least a spectral line of both the reference light beam passing through the first entrance slit and the light beam to be measured passing through the second entrance slit, to focus the spectral lines of the reflected and diffracted reference light beam and the reflected and diffracted light beam to be measured; and linear image detection means for measuring the wavelength of the focused spectral line light beam to be measured by using the wavelength of the focused spectral line of the reference light beam as a standard.
Claim 3
Dependent Claim
70 words
A spectrometer according to claim 1, wherein the detection means has a detection surface receiving the spectral lines of the reference light beam and the light beam to be measured at spaced apart locations, and the detection means measures the wavelength of the light to be measured as a difference from the wavelength of the reference light as a standard in response to the spacing between the spaced apart locations.
Claim 4
Dependent Claim
102 words
A spectrometer according to claim 1, wherein the combination of a diffraction grating and a focusing optical system is made up of a plane diffraction grating and a pair of concave mirrors, wherein both the reference light beam passing through the first entrance slit and the light beam to be measured passing through the second entrance slit are collimated by one of the concave mirrors and then are incident on the plane diffraction grating, and wherein both the diffracted reference spectral image and the diffracted spectral image to be measured are simultaneously focused on the detection means by the other concave mirror.
Claim 5
Dependent Claim
83 words
A spectrometer according to claim 1, wherein the combination of a diffraction grating and a focusing optical system is made up of a plane diffraction grating and a concave mirror, and wherein the reference light beam passing through the first entrance slit and the light beam to be measured passing through the second entrance slit are collimated by the concave mirror, and both the diffracted reference spectral image and the diffracted spectral image to be measured are simultaneously focused by the concave mirror.
Claim 6
Dependent Claim
25 words
A spectrometer according to claim 1, wherein the combination of a diffraction grating and a focusing optical system is formed of a concave diffraction grating.
Claim 7
Dependent Claim
19 words
A spectrometer according to claim 1, wherein the detection means includes a photoelectric sensor array having position resolving power.
Claim 8
Dependent Claim
27 words
A spectrometer according to claim 1, wherein a spectral line included in the line spectrum of a mercury lamp is used as the diffracted reference spectral line.
Claim 9
Dependent Claim
27 words
A spectrometer according to claim 1, wherein a spectral line emitted from a laser and having a known wavelength is used as the diffracted reference spectral line.
Claim 10
Dependent Claim
60 words
A spectrometer according to claim 1, wherein said linear image detection means has a light detecting area, and the spectrometer being so constructed, including the distance between said entrance slits, so that the focused light beam to be measured and the focused reference light beam can be focused on a common detecting area of said linear image detection means simultaneously.
Claim 11
Dependent Claim
39 words
A spectrometer according to claim 2, wherein the combination of a diffraction grating and a focusing optical system including means for enlarging the spectral lines to increase the distance between said locations and thereby improve the accuracy of detection.
Claim 12
Dependent Claim
50 words
A spectrometer according to claim 10, wherein the combination of a diffraction grating and a focusing optical system simultaneously directs the spectral lines of the reference light beam and the beam to be measured simultaneously on the detection surface and the detection means measures these locations at the same time.
Claim 13
Dependent Claim
50 words
A spectrometer according to claim 2, wherein the combination of a diffraction grating and a focusing optical system simultaneously directs the spectral lines of the reference light beam and the beam to be measured simultaneously on the detection surface and the detection means measures these locations at the same time.
Claim 14
Dependent Claim
61 words
An excimer laser apparatus comprising: an excimer laser; a spectrometer having a structure according to claim 1, for precisely measuring the wavelength of a radiation emitted from the excimer laser; and means for controlling the excimer laser on the basis of the measured wavelength of the radiation so that the wavelength of the radiation is always kept at a predetermined value.
Claim 15
Dependent Claim
70 words
The apparatus according to claim 13, wherein the detection means has a detection surface receiving the spectral lines of the reference light beam and the light beam to be measured at spaced apart locations, and the detection means measures the wavelength of the light to be measured as a difference from the wavelength of the reference light as a standard in response to the spacing between the spaced apart locations.
Claim 16
Dependent Claim
39 words
The apparatus according to claim 14, wherein the combinations of a diffraction grating and a focusing optical system including means for enlarging the spectral lines to increase the distance between said locations and thereby improve the accuracy of detection.
Claim 17
Dependent Claim
50 words
The apparatus according to claim 18, wherein the combination of a diffraction grating and a focusing optical system simultaneously directs the spectral lines of the reference light beam and the beam to be measured simultaneously on the detection surface and the detection means measures these locations at the same time.
Claim 18
Dependent Claim
97 words
A stepper comprising: a light source; a spectrometer having a structure according to claim 1, for precisely measuring the wavelength of light emitted from the light source; means for controlling the light source on the basis of the measured wavelength of the light so that the measured wavelength of the light is always kept at a predetermined value; and a projector for forming an image of a mask pattern on a semiconductor substrate, light emitted from the light source and having a wavelength kept at the predetermined value being used as the exposure light of the projector.
Claim 19
Dependent Claim
39 words
A stepper according to claim 17, wherein the combination of a diffraction grating and a focusing optical system including means for enlarging the spectral lines to increase the distance between said locations and thereby improve the accuracy of detection.
Claim 20
Dependent Claim
16 words
A stepper according to claim 17, wherein an excimer laser is used as the light source.
Claim 21
Dependent Claim
16 words
A stepper according to claim 18, wherein an excimer laser is used as the light source.
Claim 22
Dependent Claim
168 words
An excimer laser apparatus comprising: an excimer laser; a spectrometer for precisely measuring the wavelength of a radiation emitted from the excimer laser, and having a first entrance slit for passing a reference light beam therethrough, a second entrance slit for passing a light beam to be measured therethrough, a combination of a diffraction grating and a focusing optical system for reflecting and diffracting at least a spectral line of both the reference light beam passing through the first entrance slit and the light beam to be measured passing through the second entrance slit, to focus the spectral lines of the reflected and diffracted reference light beam and the reflected and diffracted light beam to be measured, and detection means for detecting the focused spectral line light beam to be measured and the focused reference light beam; and means for controlling the excimer laser on the basis of the measured wavelength of the radiation so that the wavelength of the radiation is always kept at a predetermined value.
Claim 23
Dependent Claim
168 words
An excimer laser apparatus comprising: an excimer laser; a spectrometer for precisely measuring the wavelength of a radiation emitted from the excimer laser, and having a first entrance slit for passing a reference light beam therethrough, a second entrance slit for passing a light beam to be measured therethrough, a combination of a diffraction grating and a focusing optical system for reflecting and diffracting at least a spectral line of both the reference light beam passing through the first entrance slit and the light beam to be measured passing through the second entrance slit, to focus the spectral lines of the reflected and diffracted reference light beam and the reflected and diffracted light beam to be measured, and detection means for detecting the focused spectral line light beam to be measured and the focused reference light beam; and means for controlling the excimer laser on the basis of the measured wavelength of the radiation so that the wavelength of the radiation is always kept at a predetermined value.
Claim 24
Dependent Claim
204 words
A stepper comprising: a light source; a spectrometer for precisely measuring the wavelength of light emitted from the light source, and having a first entrance slit for passing a reference light beam therethrough, a second entrance slit for passing a light beam to be measured therethrough, a combination of a diffraction grating and a focusing optical system for reflecting and diffracting at least a spectral line of both the reference light beam passing through the first entrance slit and the light beam to be measured passing through the second entrance slit, to focus the spectral lines of the reflected and diffracted reference light beam and the reflected and diffracted light beam to be measured, and detection means for detecting the focused spectral line light beam to be measured and the focused reference light beam; means for controlling the light source on the basis of the measured wavelength of the light so that the measured wavelength of the light is always kept at a predetermined value; and a projector for forming an image of a mask pattern on a semiconductor substrate, light emitted from the light source and having a wavelength kept at the predetermined value being used as the exposure light of the projector.
Claim 25
Dependent Claim
204 words
A stepper comprising: a light source; a spectrometer for precisely measuring the wavelength of light emitted from the light source, and having a first entrance slit for passing a reference light beam therethrough, a second entrance slit for passing a light beam to be measured therethrough, a combination of a diffraction grating and a focusing optical system for reflecting and diffracting at least a spectral line of both the reference light beam passing through the first entrance slit and the light beam to be measured passing through the second entrance slit, to focus the spectral lines of the reflected and diffracted reference light beam and the reflected and diffracted light beam to be measured, and detection means for detecting the focused spectral line light beam to be measured and the focused reference light beam; means for controlling the light source on the basis of the measured wavelength of the light so that the measured wavelength of the light is always kept at a predetermined value; and a projector for forming an image of a mask pattern on a semiconductor substrate, light emitted from the light source and having a wavelength kept at the predetermined value being used as the exposure light of the projector.
Claim 26
Dependent Claim
16 words
A stepper according to claim 22, wherein an excimer laser is used as the light source.
Claim 27
Dependent Claim
179 words
A spectrometer, comprising: means for passing a light beam to be measured along a first path; means for passing a reference light beam of a different wavelength from the wavelength of the light beam to be measured along a second path in spaced relationship to the first path; optical means for focusing and diffracting at least respective spectral lines of the reference light beam and light beam to be measured simultaneously with a common diffraction grating and at least one common focusing optical element and to project the spectral images of the spectral lines simultaneously; detection means having a single detection surface; means for enlarging the projected spectral lines simultaneously and forming an enlarged spectral image of the spectral lines respectively spaced apart from each other on the single detection surface at the same time; and said detection means measuring the spaced apart distance between the spectral lines of the spectral image on the surface and producing a correlated difference signal corresponding to the difference in wavelength between the reference light beam and the light beam to be measured.
Claim 28
Dependent Claim
179 words
A spectrometer, comprising: means for passing a light beam to be measured along a first path; means for passing a reference light beam of a different wavelength from the wavelength of the light beam to be measured along a second path in spaced relationship to the first path; optical means for focusing and diffracting at least respective spectral lines of the reference light beam and light beam to be measured simultaneously with a common diffraction grating and at least one common focusing optical element and to project the spectral images of the spectral lines simultaneously; detection means having a single detection surface; means for enlarging the projected spectral lines simultaneously and forming an enlarged spectral image of the spectral lines respectively spaced apart from each other on the single detection surface at the same time; and said detection means measuring the spaced apart distance between the spectral lines of the spectral image on the surface and producing a correlated difference signal corresponding to the difference in wavelength between the reference light beam and the light beam to be measured.
Claim 29
Dependent Claim
31 words
An apparatus including the spectrometer according to claim 24, further comprising: feedback means for adjusting the wavelength of the light beam to be measured by feedback responsive to the difference signal.
Claim 30
Dependent Claim
17 words
The apparatus according to claim 25, further including a laser for producing the beam to be measured.
Claim 31
Dependent Claim
34 words
The apparatus according to claim 26, further including a projector for forming an image of a mask pattern on a semiconductor substrate with at least a portion of the light beam to be measured.
Claim 32
Dependent Claim
13 words
The apparatus according to claim 26, wherein said laser is an excimer laser.
Claim 33
Independent Claim
291 words
An apparatus for producing a stabilized light source, comprising: first light source for passing a reference light beam of a known stable wavelength; a second light source, separate from said first light source, for passing a light beam to be measured and controlled to stabilize its wavelength at a wavelength different from the wavelength of the reference light beam; a combination of a diffraction grating and a focusing optical system for reflecting and diffracting at least a spectral line of both the reference light beam and the light beam to be measured, with a diffraction grating common to both the reference light beam and the light beam to be measured; means establishing separate paths for the reference light beam and the light beam to be measured from their respective sources to the combination of a diffraction grating and a focusing optical system to thereby determine the angle of incidence of the light beam to be measured and the angle of incidence of the reference light beam to the diffraction grating in correlation to the difference in their wavelength so that the spectral lines of the reference light beam and the light beam to be measured have substantially the same angle of diffraction; and detector means for simultaneously receiving the spectral lines of the reference light beam and the light beam to be measured from the diffraction grating on a common surface and producing an output signal difference correlated to the difference in wavelength between the reference light beam and the light beam to be measured in response to the spacing between the spectral lines on the surface; and feedback means for controlling the wavelength of the light beam to be measured to stabilize the same in response to the difference signal.
Claim 34
Independent Claim
291 words
An apparatus for producing a stabilized light source, comprising: first light source for passing a reference light beam of a known stable wavelength; a second light source, separate from said first light source, for passing a light beam to be measured and controlled to stabilize its wavelength at a wavelength different from the wavelength of the reference light beam; a combination of a diffraction grating and a focusing optical system for reflecting and diffracting at least a spectral line of both the reference light beam and the light beam to be measured, with a diffraction grating common to both the reference light beam and the light beam to be measured; means establishing separate paths for the reference light beam and the light beam to be measured from their respective sources to the combination of a diffraction grating and a focusing optical system to thereby determine the angle of incidence of the light beam to be measured and the angle of incidence of the reference light beam to the diffraction grating in correlation to the difference in their wavelength so that the spectral lines of the reference light beam and the light beam to be measured have substantially the same angle of diffraction; and detector means for simultaneously receiving the spectral lines of the reference light beam and the light beam to be measured from the diffraction grating on a common surface and producing an output signal difference correlated to the difference in wavelength between the reference light beam and the light beam to be measured in response to the spacing between the spectral lines on the surface; and feedback means for controlling the wavelength of the light beam to be measured to stabilize the same in response to the difference signal.
Claim 35
Dependent Claim
18 words
The apparatus according to claim 29, further including an excimer laser for producing the beam to be measured.
Claim 36
Dependent Claim
34 words
The apparatus according to claim 29, further including a projector for forming an image of a mask pattern on a semiconductor substrate with at least a portion of the light beam to be measured.
Claim 37
Dependent Claim
18 words
The apparatus according to claim 31, further including an excimer laser for producing the beam to be measured.
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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) | 1994-01-07 | 1994-07-09 | 1995-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-07 | 1998-07-09 | 1999-01-08 | $3760.00 | Window Closed / Lapsed |
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