Ultraviolet Micro-Raman Spectroscopy Stress Mapping of a 75-mm GaN-on-Diamond Wafer
Date
2016-05-23
Authors
Hancock, Bobby Logan
Nazari, Mohammad
Anderson, J.
Piner, Edwin L.
Faili, F.
Oh, S.
Twitchen, D.
Graham, S.
Holtz, Mark
Journal Title
Journal ISSN
Volume Title
Publisher
AIP Publishing
Abstract
Full-wafer stress mapping is accomplished using visible and ultraviolet (UV) micro-Raman spectroscopy of a 730-nm thick GaN layer integrated with diamond grown by chemical vapor deposition. The UV measurements taken from both sides of the wafer reveal a higher tensile stress of 0.86 ± 0.07 GPa at the free GaN surface compared to 0.23 ± 0.06 GPa from the GaN/diamond interface, each with good cross-wafer uniformity. Factors influencing the overall stress and stress gradient are understood based on relaxation from dislocations in the GaN which vary in density along the growth direction. Simulations incorporating a model for stress relaxation in the GaN elastic modulus adequately describe the observed dependence.
Description
Keywords
ultraviolet micro-raman spectroscopy, diamond, chemical vapor deposition, Physics
Citation
Hancock, B. L., Nazari, M., Anderson, J., Piner, E., Faili, F., Oh, S., Twitchen, D., Graham, S. & Holtz, M. (2016). Ultraviolet micro-Raman spectroscopy stress mapping of a 75-mm GaN-on-diamond wafer. Applied Physics Letters, 108(3), 211901.