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US5642374A Expired / Lapsed US ⏱️ 0.0 years remaining

Excimer laser device

Assignee: Komatsu Ltd
•
Filing: 1995-04-10
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Granted: 1997-06-24
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Expires: 2015-04-10
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Abstract

Abstract Aimed at preventing a laser light beam profile from fluctuating, and by using the fact that there is a substantially proportional relation between the beam profile and the charging voltage as well as between the beam profile and the composition or the total pressure of the laser gases, an excimer laser device comprises a laser chamber containing laser gases which are excited by initiating an electric discharge in the laser chamber to output laser light, a beam profile detector for detecting a beam profile of the output laser light, and a controller for controlling a electric discharge voltage (excitation intensity) and composition or total pressure of the prescribed types of laser gases in such a way that the beam profile is shaped as desired based on detection results of the beam profile detector. An excimer laser feedback control circuit detects the output laser beam width and controls the beam width by controlling one or more of the laser voltage, composition of the laser gas, pressure or partial pressure of the laser gas, or feed rate of a laser gas. The laser gas may comprise a halogen, buffer, or rare gas.

Inventors

  • 👤 Osamu Wakabayashi
  • 👤 Hakaru Mizoguchi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 11:20
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/30; H01S3/00; H01S3/10; H01S3/13; H01S3/131; H01S3/134; H01S3/14; H01S3/22; H01S3/223; H01S3/225

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 92 words
An excimer laser device comprising: a laser chamber containing a laser gas which is excited by initiating an electric discharge in the laser chamber to output laser light; beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; and discharge voltage control means for controlling the beam width by adjusting a voltage of the electric discharge in accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 2
Dependent Claim 92 words
An excimer laser device comprising: a laser chamber containing a laser gas which is excited by initiating an electric discharge in the laser chamber to output laser light; beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; and discharge voltage control means for controlling the beam width by adjusting a voltage of the electric discharge in accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 3
Dependent Claim 34 words
An excimer laser device as defined in claim 1, wherein the beam width detection means detects the beam width of the laser light in a direction substantially perpendicular to that of the electric discharge.
Claim 4
Dependent Claim 93 words
An excimer laser device comprising: a laser chamber containing laser gases, which are excited by initiating an electric discharge in the laser chamber to output laser light: beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; and gas control means for controlling the beam width by adjusting a composition or total pressure of the laser gases in accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 5
Dependent Claim 93 words
An excimer laser device comprising: a laser chamber containing laser gases, which are excited by initiating an electric discharge in the laser chamber to output laser light: beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; and gas control means for controlling the beam width by adjusting a composition or total pressure of the laser gases in accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 6
Dependent Claim 34 words
An excimer laser device as defined in claim 3, wherein the beam width detection means detects the beam width of the laser light in a direction substantially perpendicular to that of the electric discharge.
Claim 7
Dependent Claim 97 words
An excimer laser device comprising: a laser chamber containing laser gases, which are excited by initiating an electric discharge in the laser chamber to output laser light; beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; and control means for controlling the beam width by adjusting a voltage of the electric discharge and composition or total pressure of the laser gases accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 8
Dependent Claim 97 words
An excimer laser device comprising: a laser chamber containing laser gases, which are excited by initiating an electric discharge in the laser chamber to output laser light; beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; and control means for controlling the beam width by adjusting a voltage of the electric discharge and composition or total pressure of the laser gases accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 9
Dependent Claim 34 words
An excimer laser device as defined in claim 5, wherein the beam width detection means detects the beam width of the laser light in a direction substantially perpendicular to that of the electric discharge.
Claim 10
Dependent Claim 96 words
An excimer laser device comprising: a laser chamber containing laser gases including a halogen gas which are excited by initiating an electric discharge in the laser chamber to output laser light; beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; and halogen gas supply means for controlling the beam width by adjusting a feed rate of the halogen gas in accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 11
Dependent Claim 96 words
An excimer laser device comprising: a laser chamber containing laser gases including a halogen gas which are excited by initiating an electric discharge in the laser chamber to output laser light; beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; and halogen gas supply means for controlling the beam width by adjusting a feed rate of the halogen gas in accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 12
Dependent Claim 34 words
An excimer laser device as defined in claim 7, wherein the beam width detection means detects the beam width of the laser light in a direction substantially perpendicular to that of the electric discharge.
Claim 13
Dependent Claim 113 words
An excimer laser device as defined in claim 7, wherein the width profile detection means detects the beam width of the laser light in a direction substantially perpendicular to that of the electric discharge, and wherein the halogen gas supply means counts a number of pulses generated after a fresh laser gas has been sealed in the laser chamber as a result of gas replacement, feeds the halogen gas in an amount corresponding to the counted number of generated pulses, and increases the halogen gas feed rate if the beam width signal is smaller than a predetermined amount, and lowers the halogen feed rate if the beam width signal exceeds the predetermined amount.
Claim 14
Dependent Claim 130 words
An excimer laser device as defined in claim 9, wherein a tank of constant capacity is installed in a gas feed line between the laser chamber and a halogen gas supply source, wherein the halogen gas supply means performs a number of processing cycles in which the tank is filled with a a known amount of the gas from the halogen gas supply source and the halogen gas is then fed from the tank to the laser chamber via the gas feed line, a predetermined number of the processing cycles establishing an initial feed rate of the halogen gas, and wherein the feed rate of the halogen gas is changed from the initial feed rate by varying the number of processing cycles to a number other than the predetermined number.
Claim 15
Dependent Claim 130 words
An excimer laser device as defined in claim 7, where a tank of constant capacity is installed in a gas feed line between the laser chamber and a halogen gas supply source, wherein the halogen gas supply means performs a number of processing cycles in which the tank is filled with a known amount of the halogen gas from the halogen gas supply source and the halogen gas is then fed from the tank to the laser chamber via the gas feed line, a predetermined number of the processing cycles establishing an initial feed rate of the halogen gas, and wherein the feed rate of the halogen gas is changed from the initial feed rate by varying the number of processing cycles to a number other than the predetermined number.
Claim 16
Dependent Claim 48 words
An excimer laser device as defined in claim 7, wherein the halogen gas supply means calculates a number of oscillations of the laser light per unit of time and varies a replenishment amount of halogen gas in proportion to the calculated number of oscillations per unit of time.
Claim 17
Dependent Claim 63 words
An excimer laser device as defined in claim 12, wherein a constant flow control valve and a feed line shutoff valve are installed in a gas feed line arranged between the laser chamber and a halogen gas supply source, and the halogen gas supply means varies a replenishment amount of halogen gas by changing a time during which the shutoff valve remain closed.
Claim 18
Dependent Claim 84 words
An excimer laser device as defined in claim 12, where a constant flow control valve and a feed line shutoff valve are installed in a gas feed line arranged between the laser chamber and a halogen gas supply source, and the halogen gas supply means varies the replenishment amount by opening the shutoff valve for a predetermined amount of time and changing a value of a constant flow rate controlled by the constant flow control valve in accordance with the calculated number of oscillations.
Claim 19
Dependent Claim 63 words
An excimer laser device as defined in claim 7, where a constant flow control valve and a feed line shutoff valve are installed in a gas feed line arranged between the laser chamber and a halogen gas supply source, and the halogen gas supply means varies a replenishment amount of halogen gas by changing a time during which the shutoff valve remains closed.
Claim 20
Dependent Claim 98 words
An excimer laser device comprising: a laser chamber containing laser gases including a rare earth gas, which are excited by initiating an electric discharge in the laser chamber to output laser light; and beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; and rare gas supply means for controlling the beam width by adjusting a feed rate of the rare gas in accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 21
Dependent Claim 98 words
An excimer laser device comprising: a laser chamber containing laser gases including a rare earth gas, which are excited by initiating an electric discharge in the laser chamber to output laser light; and beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; and rare gas supply means for controlling the beam width by adjusting a feed rate of the rare gas in accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 22
Dependent Claim 34 words
An excimer laser device as defined in claim 16, wherein the beam width detection means detects the beam width of the laser light in a direction substantially perpendicular to that of the electric discharge.
Claim 23
Dependent Claim 130 words
An excimer laser device as defined in claim 16, wherein a tank of constant capacity is installed in a gas feed line between the laser chamber and a rare gas supply source, wherein the rare gas supply means performs a number of processing cycles in which the tank is filled with a a known amount of the gas from the rare gas supply source and the rare gas is then fed from the tank to the laser chamber via the gas feed line, a predetermined number of the processing cycles establishing an initial feed rate of the rare gas, and wherein the feed rate of the rare gas is changed from the initial feed rate by varying the number of processing cycles to a number other than the predetermined number.
Claim 24
Dependent Claim 151 words
An excimer laser device comprising: a laser chamber containing laser gases which are excited by initiating an electric discharge in the laser chamber to output laser light; power detection means for detecting power of the output laser light and outputting a power signal; beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; discharge voltage control means for controlling the power of the laser light by adjusting a voltage of the electric discharge in accordance with a difference between an amplitude of the power signal output from the power detection means and a target power signal; gas control means for controlling the beam width by adjusting a composition or total pressure of the laser gases in accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.
Claim 25
Dependent Claim 151 words
An excimer laser device comprising: a laser chamber containing laser gases which are excited by initiating an electric discharge in the laser chamber to output laser light; power detection means for detecting power of the output laser light and outputting a power signal; beam width detection means for detecting a beam width of the output laser light and outputting a beam width signal; discharge voltage control means for controlling the power of the laser light by adjusting a voltage of the electric discharge in accordance with a difference between an amplitude of the power signal output from the power detection means and a target power signal; gas control means for controlling the beam width by adjusting a composition or total pressure of the laser gases in accordance with a difference between an amplitude of the beam width signal output from the beam width detection means and a target beam width signal.

References Cited (Backward Citations)

US5142543A Cited
US4958356A Cited
US5450436A Cited
US5440578A Cited
US5440578B1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-06-23 2000-12-23 2001-06-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-06-23 2004-12-23 2005-06-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-06-23 2008-12-23 2009-06-24 $7700.00 Window Closed / Lapsed

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