Microstructures formed on silicon wafer by CO2 laser irradiation

Weijie Wang; Yongfeng Lu; Chengwu An; Minghui Hong

doi:10.1117/12.456859

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25 February 2002 Microstructures formed on silicon wafer by CO₂ laser irradiation

Weijie Wang, Yongfeng Lu, Chengwu An, Minghui Hong

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Proceedings Volume 4426, Second International Symposium on Laser Precision Microfabrication; (2002) https://doi.org/10.1117/12.456859
Event: Second International Symposium on Laser Precision Micromachining, 2001, Singapore, Singapore

Abstract

Laser bumps have been formed on the silicon surface with anisotropic patterns induced by the pulsed CO₂ laser under the backside effect conditions. The microstructures are formed with periodic patterns, and vary with the laser parameters. The parallel narrow fringes have period around 2 micrometers , and the fringe orientation is in parallel with the laser polarization direction. The circular fringes with spacing around 1 micrometers appear when the laser energy increase. The fringe patterns were found to be independent on the laser pulses, therefore are re-writable. The bump formation mechanism is considered to be thermal capillary wave effect during the material melting and resolidification processes under laser irradiation. Whereas, the laser absorption may be induced by the hot electrons, or the thermal energy resulting from the laser interaction with the backside coating material.

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Weijie Wang, Yongfeng Lu, Chengwu An, and Minghui Hong "Microstructures formed on silicon wafer by CO₂ laser irradiation", Proc. SPIE 4426, Second International Symposium on Laser Precision Microfabrication, (25 February 2002); https://doi.org/10.1117/12.456859

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