Xu, L;Lowney, D;McNally, PJ;Borowiec, A;Lankinen, A;Tuomi, TO;Danilewsky, AN

2007

August

Semiconductor Science and Technology

Femtosecond versus nanosecond laser micro-machining of InP: a nondestructive three-dimensional analysis of strain

Published

4 ()

X-RAY TOPOGRAPHY INDIUM-PHOSPHIDE MECHANICAL STRESSES RAMAN-SCATTERING DAMAGE GAAS IRRADIATION AIR GE

22

970

979

Ultra-fast femtosecond laser micro-machining can lead to improved surface morphology and a reduction in the heat-affected zone. In this paper, synchrotron x-ray topography (SXRT) and micro-Raman spectroscopy have been used as nondestructive tools to compare the residual strain in InP substrates after femtosecond (fs) and nanosecond (ns) laser processing. Two-dimensional stain distributions with varying probing depth and cross-section images across the four laser machined grooves were obtained. The recrystallized poly-InP layer on the laser machined groove surface has been found to be highly strained in tension, and the stress magnitude is much bigger than the shear stress introduced by crystal distortion underneath. After comparing the simulation results of SXRT orientation contrast with the topography images, the nature of the crystal plane distortion induced by both fs and ns laser machining methods was elucidated.

BRISTOL

0268-1242

10.1088/0268-1242/22/8/024