Crystal structure of laser-induced subsurface modifications in Si

• Published in: Applied physics. A, Materials science & processing Vol. 120; no. 2; pp. 683 - 691
• Main Authors: Verburg, P. C., Smillie, L. A., Römer, G. R. B. E., Haberl, B., Bradby, J. E., Williams, J. S., Huis in ’t Veld, A. J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 04-06-2015; Springer
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Machines; Manufacturing; MATERIALS SCIENCE; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; Surfaces and Interfaces; Thin Films; Raman Spectroscopy; Pulse Energy; Nanosecond Pulse; Defect Line; Optical Axis
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-015-9238-5

Laser-induced subsurface modification of dielectric materials is a well-known technology. Applications include the production of optical components and selective etching. In addition to dielectric materials, the subsurface modification technology can be applied to silicon, by employing near to mid-infrared radiation. An application of subsurface modifications in silicon is laser-induced subsurface separation, which is a method to separate wafers into individual dies. Other applications for which proofs of concept exist are the formation of waveguides and resistivity tuning. However, limited knowledge is available about the crystal structure of subsurface modifications in silicon. In this work, we investigate the geometry and crystal structure of laser-induced subsurface modifications in monocrystalline silicon wafers. In addition to the generation of lattice defects, we found that transformations to amorphous silicon and Si
-iii
/Si
-xii
occur as a result of the laser irradiation.