Formation mechanism of bubbles in the surface of films induced by long pulse width laser

Bubbles caused by laser irradiation can be observed usually via microscope during the experiments of laser induced damage of films, each bubble looks large and very symmetry. From the point of gasification of impurity, we have analyzed the formation mechanism of bubbles in the surface of films using model of a spherical shell which endures high inner pressure. The results reveal that films are more easily damaged when the size of the inclusion is large or the embedment is shallow. At the first time of damage occurred, the bubble is larger when the size of inclusion or the embedded depth is larger. The coupling model of thermal-elastic makes up the present theory and adapts to higher temperature.