Study On The Process And Mechanism Of Excimer Laser Micro-Machining

In this paper the mechanism of ultra-violet photons and polymer molecules interaction and models of excimer laser etching polymer are studied. The mechanism of excimer laser etching PMMA and PTFE is experimentally investigated using Raman spectroscopy, X-ray photo-electro spectroscopy, SEM, and 3-D surface analyzer. The process of excimer laser etching PMMA is researched in detail and the etched surfaces of polymer are improved. The physical and chemical processes of ultra excimer laser etching polymer molecules are studied, further more, the physical and chemical models of excimer laser etching polymers and their mechanism are summarized. The chemical structural changes of PMMA and PTFE after etching are analyzed by Raman spectroscopy and X-ray photo-electro spectroscopy, and based on atoms and molecules analysis the mechanism of photon absorption and bonds dissociation in the process of 248nm excimer laser etching PMMA and PTFE are investigated. The etching rate, roughness versus incident laser fluences and pulse number are investigated theoretically and experimentally in detail by 3-D surface analyzer. It is found that etching rate decreases with increasing incident fluences, so the influence of plume in the etching process is studied. Moreover, a high-speed nitrogen gas flow is spurted onto the etched areas, and the residues at the etched surfaces sharply decrease wihle the etching rate and roughness are not influenced.