Output stabilization technology with chemical impurity control on ArF excimer laser

Sumitani, Akira; Andou, Satoshi; Watanabe, Takehito; Konishi, Masayuki; Egawa, Suguru; Uchino, Ikuo; Ohta, Takao; Terashima, Katsutomo; Suzuki, Natsushi; Enami, Tatsuo; Mizoguchi, Hideaki

doi:10.1117/12.388980

Cited by 6 publications

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“…The latter requires a custom-made laser chamber that suppresses the generation of impurity gases. [11][12][13] However, even for a high-purity gas containing Xe at 10 ppm inside the custom-made laser chamber, we observed a steplike decrease in the output energy of the ArF excimer laser under burst-mode operation. The steplike energy decrease occurred just after the first circulation of the laser gas in the chamber.…”

Section: Introductionmentioning

confidence: 73%

“…Various tests [12][13][14] concerning the steplike energy decrease of the ArF excimer laser confirmed that the energy recovers after a rest time of approximately 0.2 s during burst operation, and that the ratio of the decrease in the energy decreases with increasing gas temperature. Because the absorbing compound F x O y is unstable, its dissociation time and the dependences of its concentration on gas temperature and initial oxygen concentration were investigated.…”

Section: Temporal Variations In Absorption At 193 Nm For Different Ga...mentioning

confidence: 90%

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Elucidation of Steplike Output Energy Decrease Observed in ArF Excimer Laser for Microlithography

Sumitani

Ishihara

Fukuoka

et al. 2007

jjap

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A steplike decrease in the output energy of an ArF excimer laser for microlithography is caused by the laser light absorption in the laser gas. To identify the absorbing gas component, the light absorption characteristics of the laser gas inside the discharge chamber were investigated under various gas conditions using a continuous xenon light source in the ultraviolet region and an ArF excimer laser at 193 nm. As a result, the oxygen-fluorine compound F x O y generated in the laser discharge was identified as the absorbing molecule, because a strong steplike absorption of the 193 nm laser light was only observed when oxygen and fluorine were added together to the discharge gas. The lifetime of this absorbing molecule was examined against gas temperature during the operation of the laser discharge. The data obtained were useful in setting the best operational conditions for the ArF excimer laser for microlithography.

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Section: Introductionmentioning

confidence: 73%

Section: Temporal Variations In Absorption At 193 Nm For Different Ga...mentioning

confidence: 90%

Elucidation of Steplike Output Energy Decrease Observed in ArF Excimer Laser for Microlithography

Sumitani

Ishihara

Fukuoka

et al. 2007

jjap

Self Cite

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“…The laser is sensitive to the harmful gas HF, , , , etc [14, 15] . Sumitani pointed out the addition of only 10 ppm (parts per million) HF or may cause the output energy of ArF excimer laser reduce 10% [16] . The studies on metal and fluorine showed that the reaction includes the fluoride of the elements and the diffusion of the free fluorine [17, 18] , and the reaction layer is mainly composed of fluoride [19] .…”

Section: Introductionmentioning

confidence: 99%

Corrosion behaviors of the copper alloy electrodes in ArF excimer laser operation process

Guo

Ding

Zhou

et al. 2018

High Pow Laser Sci Eng

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The corrosion behaviors of the ArF excimer laser copper alloy electrodes were studied. The morphology, composition and impurities were characterized by optical microscope, scanning electron microscopy, electron microprobe and glow discharge mass spectrometer methods. The anode produces the reef, the corrosion pits, the hole layer and the $1{-}10~\unicode[STIX]{x03BC}\text{m}$ level flake impurity. The cathode produces the particles, the sputtering pits, the element reduce layer and the $1~\unicode[STIX]{x03BC}\text{m}$ level particle impurity. Besides the Cu element, other elements in the alloy participate in the corrosion: Al element in the reef is over 1.5 times of the anode, Zn element in the particles is 1.3 times of the cathode, many trace elements congregate on the copper surface several and even hundreds of times. These elements are responsible to a great degree for the impurities and the rapid energy decline of the long-time idled laser.

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“…It is well known that both parameters are significantly improved by adding a small amount (typically 10 ppm) of xenon (Xe) 9,10) and by controlling concentration of impurity gases such as oxygen (O 2 ) and hydrogen fluoride (HF) to be below 10 ppm. 11,12) In order to maintain the concentration of impurities at the lowest level, we have developed a specially designed laser chamber 13) that can suppress the generation of impurity gases. However, even for a high-purity gas containing Xe at 10 ppm and the special laser chamber, we observed a steplike decrease of the output energies of the ArF excimer laser under the burst operation.…”

mentioning

confidence: 99%

Investigation of a Step-Like Output Energy Decrease Observed in an ArF Excimer Laser for Microlithography

Sumitani

Ishihara

Fukuoka

et al. 2006

jjap

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A step-like decrease of the output energy of an ArF excimer laser for microlithography has been observed during highrepetition rate and high-power operation. The reason for the step-like energy decrease was traced to oxygen by adding 50 ppm of various gas impurities to the laser gas. It is supposed that the energy decrease is caused by laser light absorption due to the oxygen or to some kinds of oxygen compounds because no change was observed in ArF and XeF emission intensities which were monitored as measures of excimer formation, Xe content, and discharge states.

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Output stabilization technology with chemical impurity control on ArF excimer laser

Cited by 6 publications

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Elucidation of Steplike Output Energy Decrease Observed in ArF Excimer Laser for Microlithography

Elucidation of Steplike Output Energy Decrease Observed in ArF Excimer Laser for Microlithography

Corrosion behaviors of the copper alloy electrodes in ArF excimer laser operation process

Investigation of a Step-Like Output Energy Decrease Observed in an ArF Excimer Laser for Microlithography

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