Thermal Effect Characterization of Laser-Ablated Silicon-Through Interconnect

As to the wafer through holes formation, methods such as reactive ion beam (RIE) and inductive coupled plasma (ICP) were used usually. In this paper, we use UV laser to study hole formation in silicon wafer. Siemens Dematic Microbeam 3205 laser machine with a 355nm wavelength was used in this study. Laser drilling is a non-contact manufacture method, it can apply high energy to a small spot (15mum focused beam diameter) to ablate and remove the material. The advantage of a UV laser process compared to lithography by masks is its capability of local alignment. While a mask has to be aligned to the whole panel, the laser can use local fiducial marks, allowing a higher accuracy and yield by laser drilling. We choose laser drilling process to make the efficient through holes in this paper. Hole drilling in silicon wafer by short pulse laser. Thermal and mechanical effects on silicon wafer induced by laser drilling were analyzed was characterized under optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS)