Thermodynamic effects of pulsed laser multilayer thin film etching

Abstract

The impact of the interface effect on the etching accuracy of a non-single-layer structure was utilized as a starting point in this work to analyze the correlation between the integrated structure's film surface/interface temperature field, stress field distribution, and interface mutation. Based on single-factor etching experiments, the relationship between the temperature field, stress field, and laser characteristic parameters was evaluated via a combination of theoretical analysis and numerical simulation. For polyimide-based metal aluminum film, a connection between scanning speed and etching characteristic parameters was discovered. The results illustrate that when Al/PI (aluminum film thickness of 2μm) was irradiated by a laser, the interface temperature reached a certain value, which caused distortion of the film and substrate. Changes in the distribution of the temperature and stress fields of the film affect the heat transfer in the system and thus affect the thermodynamic trajectory, thermal feedback, etching rate, and shape of the target film surface. Ultimately, the etching and removal of the Al/PI integration of the non-single-layer structure are attributed to the interplay of thermal and stress field effects.