[The mechanism of laser induced damage to film by metal impurity particle].

The film can be easily damaged by impurity particles, and the damage characteristics of HfO2 film produced by metal particles and the corresponding thermodynamic process were studied. The strong absorption of laser light by metal particles can make film melt, gasified and ionized, and by this way, the film can be peeled and form tround pits point; The metal particle size is closely related to the processes of laser absorption, thermal diffusivity and thermal expansion closely related effects, etc. Under the same irritation energy, the temperature rise is determined by particle size, which can make different size of film damage pits. There is a certain size of metal particle which cause the highest temperature rise and make the film damage easily. Based on the analysis of irradiation ionization effects of laser plasma emission spectrum of the metal particles, the radiation spectrum is mainly focused on the ultraviolet part and photon energy is higher than the incident laser, which has stronger ionization effects, exacerbating the film removal.