EXCIMER LASER APPARATUS AND EXCIMER LASER SYSTEM

• US 20160254634A1
• Filed: 05/10/2016
• Published: 09/01/2016
• Est. Priority Date: 12/25/2013
• Status: Active Grant

• Current Assignee: Gigaphoton, Inc. (Komatsu)
• Original Assignee: Gigaphoton, Inc. (Komatsu)
• Inventors: ASAYAMA, Takeshi, WAKABAYASHI, Osamu, KAKIZAKI, Kouji
• Granted Patent: US 9,837,780 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01S 3/036 Means for obtaining or maintaining the desired gas pressure within the tube, e.g. by gettering, replenishing; Means for circulating the gas, e.g. for equalising the pressure within the tube H01S3/031 takes precedence
• CPC Class Codes: H01S 3/038 Electrodes, e.g. special shape, configuration or composition
• CPC Class Codes: H01S 3/134 in gas lasers
• CPC Class Codes: H01S 3/225 comprising an excimer or exciplex

Abstract

The excimer laser apparatus may include a laser chamber configured to contain gas, a pair of electrodes provided in the laser chamber, a power source unit configured to supply a pulse voltage between the pair of electrodes, a gas supply unit configured to supply gas into the laser chamber, a gas exhaust unit configured to partially exhaust gas from within the laser chamber, and a gas control unit configured to control the gas supply unit and the gas exhaust unit, where a replacement ratio of gas to be replaced from within the laser chamber increases as deterioration of the pair of electrodes progresses, the deterioration being represented by a deterioration parameter of the pair of electrodes.

Claims

1. An excimer laser apparatus comprising:

a laser chamber configured to contain gas;

a pair of electrodes provided in the laser chamber;

a power source unit configured to supply a pulse voltage between the pair of electrodes;

a gas supply unit configured to supply gas into the laser chamber;

a gas exhaust unit configured to partially exhaust gas from within the laser chamber; and

a gas control unit configured to control the gas supply unit and the gas exhaust unit, where a replacement ratio of gas to be replaced from within the laser chamber increases as deterioration of the pair of electrodes progresses, the deterioration being represented by a deterioration parameter of the pair of electrodes.

2. The excimer laser apparatus according to claim 1, wherein

the gas control unit is configured to determine a replacement amount of gas to be replaced from within the laser chamber based on the deterioration parameter of the pair of electrodes, and

the gas control unit is configured to control the gas supply unit and the gas exhaust unit to replace the replacement amount of gas thus determined from within the laser chamber.

4. The excimer laser apparatus according to claim 1, wherein

the deterioration parameter of the pair of electrodes is a total number indicating how many pulses of the pulse voltage have been supplied between the pair of electrodes since the pair of electrodes was installed in the laser chamber.

5. The excimer laser apparatus according to claim 4, further comprising:

an input unit configured to input an initial value of a total number indicating how many pulses of pulse voltage have been supplied between the pair of electrodes; and

a laser control unit configured to add, to the initial value, a number indicating how many pulses of the pulse voltage were additionally supplied between the pair of electrodes.

6. The excimer laser apparatus according to claim 1, wherein

the deterioration parameter of the pair of electrodes is an integrated value of input energy having been inputted to the pair of electrodes since the pair of electrodes was installed in the laser chamber.

7. The excimer laser apparatus according to claim 6, further comprising:

an input unit configured to input an initial value of an integrated value of input energy inputted to the pair of electrodes; and

a laser control unit configured to add, to the initial value, a value of input energy additionally inputted to the pair of electrodes.

8. The excimer laser apparatus according to claim 1, wherein

the deterioration parameter of the pair of electrodes is a stability of pulse energy of a laser beam outputted from the laser chamber.

9. The excimer laser apparatus according to claim 1, wherein

the deterioration parameter of the pair of electrodes is a proximity of pulse energy of a laser beam to a target value, the laser beam being outputted from the laser chamber.

10. The excimer laser apparatus according to claim 1, wherein

the deterioration parameter of the pair of electrodes is a number indicating how many pulses of the pulse voltage have been supplied between the pair of electrodes since a gas replacement of the laser chamber was performed, the gas replacement including exhausting gas within the laser chamber to the extent that operation of the laser chamber cannot be continued and then supplying new gas into the laser chamber.

11. The excimer laser apparatus according to claim 1, wherein

the deterioration parameter of the pair of electrodes is an elapsed time since a gas replacement of the laser chamber was performed, the gas replacement including exhausting gas within the laser chamber to the extent that operation of the laser chamber cannot be continued and then supplying new gas into the laser chamber.

12. The excimer laser apparatus according to claim 1, wherein

the deterioration parameter of the pair of electrodes is a voltage value of the pulse voltage supplied between the pair of electrodes.

13. The excimer laser apparatus according to claim 1, wherein

the deterioration parameter of the pair of electrodes is input energy inputted to the pair of electrodes.

3. The excimer laser apparatus according to claim wherein

the gas control unit is configured to determine a time interval of gas replacement from within the laser chamber based on the deterioration parameter of the pair of electrodes, and

the gas control unit is configured to control the gas supply unit and the gas exhaust unit to replace gas at the time interval thus determined.

14. An excimer laser apparatus comprising:

a laser chamber configured to contain gas;

a pair of electrodes provided in the laser chamber;

a power source unit configured to supply a pulse voltage between the pair of electrodes;

a gas supply unit configured to supply gas into the laser chamber;

a gas exhaust unit configured to partially exhaust gas from within the laser chamber; and

a gas control unit configured to

control the gas supply unit and the gas exhaust unit to replace a first amount of gas corresponding to a first ratio to the total amount of gas in the laser chamber when a deterioration parameter of the pair of electrodes has a first value,

control the gas supply unit and the gas exhaust unit to replace a second amount of gas corresponding to a second ratio to the total amount of gas in the laser chamber when the deterioration parameter of the pair of electrodes has a second value, the second ratio being higher than the first ratio, and the second value representing more progressed deterioration of the pair of electrodes than the first value.

15. An excimer laser apparatus comprising:

a laser chamber configured to contain gas;

a pair of electrodes provided in the laser chamber;

a power source unit configured to supply a pulse voltage between the pair of electrodes;

a gas supply unit configured to supply gas into the laser chamber;

a gas exhaust unit configured to partially exhaust gas from within the laser chamber; and

a gas control unit configured to, based on a deterioration parameter of the pair of electrodes,

control the gas supply unit and the gas exhaust unit to increase a replacement amount of gas to be replaced from within the laser chamber as the deterioration parameter changes to show that deterioration of the pair of electrodes progresses,

output a life expiration signal when the deterioration parameter shows a life expiration of the pair of electrodes, and

further increase the replacement amount of gas to be replaced from within the laser chamber upon receiving a life prolonging command after outputting the life expiration signal.

16. The excimer laser apparatus according to claim 15, wherein

the gas control unit sets the replacement amount of gas to be replaced from within the laser chamber, the replacement amount after receiving the life prolonging command having 1.5 times or more and 3 times or less than the replacement amount before receiving the life prolonging command.

17. The excimer laser apparatus according to claim 15, further comprising:

an alarm device configured to inform a user of the life expiration of the pair of electrodes based on the life expiration signal; and

an input device configured to accept an input of the life prolonging command.