Abstract
Si K-edge x-ray absorption spectroscopy (XAFS) has been used to study the local structure of Si dopant in GaN crystalline material. Doping concentrations NSi from 8.0×1016 to 4.4×1019 cm−3 were investigated. It is observed that the near-edge spectra vary significantly as a function of NSi. At low concentrations the Si K-edge spectra exhibit features similar to that obtained from N K-edge measurement, while at high concentrations the near-edge spectra shape is similar to that recorded from Si3N4. We interpret the results as an indication that Si is not randomly distributed. The changes of the near-edge spectra as a function of doping level is explained as due to changes in the magnitude of Si local lattice contraction caused by the formation of various types of Si clusters. The interpretation is further supported by extended XAFS spectra analysis. A Si-induced strain-field near the surface is proposed as the main force for the cluster formation during epitaxial growth.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
