A unified model to determine the energy partitioning between target and plasma in nanosecond laser ablation of silicon

• DOI: 10.1063/1.4915118
• Publication Date: 2015-03-23T18:16:55Z
• Authors: G. Galasso; M. Kaltenbacher; A. Tomaselli; D. Scarpa
• Keywords: Laser Ablation; Nanosecond

In semiconductor industry, pulsed nanosecond lasers are widely applied for the separation of silicon wafers. Here, high intensities employed activate a cascade complex multi-physical and multi-phase mechanisms, which finally result in formation laser induced plasma, shielding target from incoming beam. Such plasma plume, by preventing to effectively reach target, reduces overall efficiency controllability ablation process. Modelling can be useful tool optimization industrial applications, allowing deeper understanding way energy distributes between plasma. Nevertheless, highly character poses serious challenges on implementation various mechanisms underlying process within common modelling framework. A novel strategy is here proposed order simulate simplified, yet physically consistent way, typical application as Reasonable agreement with experimental findings obtained. Three fundamental have been identified main factors influencing accuracy numerical predictions: transition evaporative volumetric mass removal occurring at critical temperature, collisional radiative processes initial stage increased impact liquid ejection mechanism when sub-millimeter footprint used.