Optical and structural characteristics of virtually unstrained bulk-like GaN
2004 (English)In: Japanese Journal of Applied Physics, ISSN 0021-4922, Vol. 43, no 4A, 1264-1268 p.Article in journal (Refereed) Published
Bulk-like GaN with high structural and optical quality has been attained by hydride vapor-phase exitapy (HVPE). The as-grown 330 mum-thick GaN layer was separated from the sapphire substrate by a laser-induced lift-off process. The full width at half maximum values of the X-ray diffraction (XRD) omega-scans of the free-standing material are 96 and 129 arcsec for the (1 0 -1 4) and (0 0 0 2) reflection, respectively, which rank among the smallest values published so far for free-standing HVPE-GaN. The dislocation density determined by plan-view TEM images is 1-2 x 10(7) cm(-2). Positron annihilation spectroscopy studies show that the concentration of Ga vacancy related defects is about 1.5 x 10(16) cm(-3). The high-resolution XRD, photoluminescence, mu-Raman, and infrared spectroscopic ellipsometry measurements consistently prove that the free-standing material is of high crystalline quality and virtually strain-free. Therefore it is suitable to serve as a substrate for stress-free growth of high-quality III-nitrides based device heterostructures.
Place, publisher, year, edition, pages
2004. Vol. 43, no 4A, 1264-1268 p.
GaN, HVPE, bulk-like, optical and structural characteristics, stress-free
National CategoryEngineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-46236DOI: 10.1143/JJAP.43.1264OAI: oai:DiVA.org:liu-46236DiVA: diva2:267132