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A krypton fluoride laser (KrF laser) is a particular type of excimer laser,〔Basting, D. and Marowsky,G., Eds., ''Excimer Laser Technology,'' Springer, 2005.〕 which is sometimes (more correctly) called an exciplex laser. With its 248 nanometer wavelength, it is a deep ultraviolet laser which is commonly used in the production of semiconductor integrated circuits, industrial micromachining, and scientific research. The term excimer is short for 'excited dimer', while exciplex is short for 'excited complex'. An excimer laser typically uses a mixture of a noble gas (argon, krypton, or xenon) and a halogen gas (fluorine or chlorine), which under suitable conditions of electrical stimulation and high pressure, emits coherent stimulated radiation (laser light) in the ultraviolet range. KrF (and ArF) excimer lasers are widely used in high-resolution photolithography machines, one of the critical technologies required for microelectronic chip manufacturing. Excimer laser lithography〔Jain, K. “Excimer Laser Lithography”, SPIE Press, Bellingham, WA, 1990.〕 has enabled transistor feature sizes to shrink from 800 nanometers in 1990 to below 45 nanometers in 2010.〔La Fontaine, B., (“Lasers and Moore’s Law” ), SPIE Professional, Oct. 2010, p. 20.〕 ==Theory== A krypton fluoride laser absorbs energy from a source, causing the krypton gas to react with the fluorine gas producing krypton fluoride, a temporary complex, in an excited energy state: :2 Kr + → 2 KrF The complex can undergo spontaneous or stimulated emission, reducing its energy state to a metastable, but highly repulsive ground state. The ground state complex quickly dissociates into unbound atoms: :2 KrF → 2 Kr + The result is an exciplex laser that radiates energy at 248 nm, which lies in the near ultraviolet portion of the spectrum, corresponding with the energy difference between the ground state and the excited state of the complex. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Krypton fluoride laser」の詳細全文を読む スポンサード リンク
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