METHOD AND APPARATUS FOR PREVENTING LASER ENTRANCE WINDOW FROM CONTAMINATION

摘要

PROBLEM TO BE SOLVED: To assuredly change the flying orbit and to effectively prevent evaporated materials from depositing to a laser entrance window, by ionizing the material produced from a work by the laser irradiation, and changing the flying orbit of the ionized material. SOLUTION: For annealing, a laser abrasion is applied to a work 2 to provide an evaporated material, on ionizer 12 irradiates an ultraviolet ray or electrons to ionize this material stably, and an orbit changer 13 immediately changes the orbit of the ionized material by acting on repelling or attracting force for changing the orbit depending on the polarity of the potential in the changer 13. If magnifying this action, the material can be repalled or attracted. The energy of particles dispersed by the abrasion is at most about 100eV.