Characterization of InN epilayers grown on Si(1 1 1) substrates at various temperatures by MBE

✍ Scribed by Yan-Hsin Wang; Wei-Li Chen; Ming-Fei Chen

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 475 KB
• Volume: 41
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/j.physe.2009.06.005

✦ Synopsis

InN films have been grown by plasma-assisted molecular beam epitaxy (PAMBE) and characterized by various technologies. It was found that the structural, optical and electrical properties can be drastically improved by raising growth temperature from 440 to 525 1C. Grainy morphology was found in the grain size was found in atomic force microscope images. The large grain size was about 360 nm for a film grown at 525 1C. These films exhibited Wurtzite structure with a c/a ratio ranging from 1.59 to 1.609. The dislocation densities estimated by X-ray diffraction techniques closely agreed with those analyzed by plan-view transmission electron microscopy. Photoluminescence (PL) studies confirmed near bandto-band transitions and the narrowest low-temperature PL peak width was found to be 24 meV at 0.666 eV. Carrier concentrations decreased from 1.44 Â 10 19 to 1.66 Â 10 18 cm À3 and Hall mobility increased from 226 to 946 cm 2 V À1 s À1 as the growth temperature is progressively increased from 440 to 525 1C. Raman spectra also indicated improved crystal quality as the growth temperature was raised.