Principles and applications of trans-wafer processing using a 2-μm thulium fiber laser
- 3 October 2015
- journal article
- Published by Springer Science and Business Media LLC in The International Journal of Advanced Manufacturing Technology
- Vol. 84 (9-12), 2567-2578
- https://doi.org/10.1007/s00170-015-7870-z
Abstract
A self-developed nanosecond-pulsed thulium fiber laser operating at the wavelength λ = 2 μm was used to selectively modify the front and the back surfaces of various uncoated and metal-coated silicon and gallium arsenide wafers utilizing transparency of semiconductors at this wavelength. This novel processing regime was studied in terms of the process parameter variations, i.e., pulse energy and pulse duration, and the corresponding modification fluence thresholds were determined. The results revealed nearly debris-free back surface processing of wafers, in which modifications could be induced without affecting the front surfaces. The back surface modification threshold of Si was significantly higher than at the front surface due to non-linear absorption and aberration effects observed in experiments. A qualitative study of the underlying physical mechanisms responsible for material modification was performed, including basic analytical modeling and z-scan measurements. Multi-photon absorption, surface-enhanced absorption at nano- and microscopic defect sites, and damage accumulation effects are considered the main physical mechanisms accountable for consistent surface modifications. Applications of trans-wafer processing in removal of thin single- and multi-material layers from the back surface of Si wafers, both in single tracks and large areas, are presented.Keywords
This publication has 29 references indexed in Scilit:
- Confined micro-explosion induced by ultrashort laser pulse at SiO2/Si interfaceApplied Physics A, 2013
- Excimer laser doping using highly doped silicon nanoparticlesPhysica Status Solidi (a), 2013
- Laser-Induced Resistance Fine Tuning of Integrated Polysilicon Thin-Film ResistorsIEEE Transactions on Electron Devices, 2010
- Laser-induced damage threshold of silicon in millisecond, nanosecond, and picosecond regimesJournal of Applied Physics, 2010
- Ultraviolet femtosecond, picosecond and nanosecond laser microstructuring of silicon: structural and optical propertiesApplied Optics, 2008
- Advanced Dicing Technology for Semiconductor Wafer—Stealth DicingIEEE Transactions on Semiconductor Manufacturing, 2007
- Ablation and cutting of planar silicon devices using femtosecond laser pulsesApplied Physics A, 2003
- Free-form laser consolidation for producing metallurgically sound and functional componentsJournal of Laser Applications, 2000
- Laser induced damage in GaAs at 1.06 μm wavelength: surface effectsOptics & Laser Technology, 1996
- Laser Processing of SemiconductorsPublished by Elsevier BV ,1983