Characterisation of GaN films grown on sapphire by low-temperature cyclic pulsed laser deposition/nitrogen rf plasma

Abstract GaN thin films grown by cyclic pulsed laser deposition were characterised by X-ray diffraction (XRD), photoluminescence (PL), and atomic force microscopy. Films were grown on pre-nitridated c -plane sapphire at two substrate temperatures (600 and 650 °C). Films deposited at 650 °C exhibit a higher growth rate which is reflected in the XRD intensity along the GaN (0 0 0 2) direction. At this substrate temperature, the quality of the PL spectrum was the best. The typical yellow luminescence, YL (2.2 eV) was dominant at the lower deposition temperature. For this substrate temperature change, the near band edge emission (NBE) to YL ratio increased from 0.3 to a value of 17. This NBE emission was peaked at 3.47 eV with a FWHM of 200 meV at 14 K. Optimisation of deposition parameters is suggested to further improve the quality of binary films.

[1]  T. Seong,et al.  Growth of high-quality GaN on Si(111) substrate by ultrahigh vacuum chemical vapor deposition , 2001 .

[2]  Deliang Wang,et al.  Growth of hexagonal GaN on Si(111) coated with a thin flat SiC buffer layer , 2000 .

[3]  IMPURITY CONTAMINATION OF GAN EPITAXIAL FILMS FROM THE SAPPHIRE, SIC AND ZNO SUBSTRATES , 1997 .

[4]  Hsiang-Jen Huang,et al.  Photoluminescence and photoluminescence excitation studies of as-grown and P-implanted GaN: On the nature of yellow luminescence , 2002 .

[5]  Kovalev,et al.  Properties of the yellow luminescence in undoped GaN epitaxial layers. , 1995, Physical review. B, Condensed matter.

[6]  Sven Öberg,et al.  DEEP ACCEPTORS TRAPPED AT THREADING-EDGE DISLOCATIONS IN GAN , 1998 .

[7]  Risto M. Nieminen,et al.  Point-defect complexes and broadband luminescence in GaN and AlN , 1997 .

[8]  Jörg Neugebauer,et al.  Gallium vacancies and the yellow luminescence in GaN , 1996 .

[9]  Shuji Nakamura,et al.  InGaN multi‐quantum‐well structure laser diodes grown on MgAl2O4 substrates , 1996 .

[10]  Jari Likonen,et al.  Influence of dopants and substrate material on the formation of Ga vacancies in epitaxial GaN layers , 2001 .

[11]  Epitaxial growth of GaN thin film on sapphire with a thin ZnO buffer layer by liquid target pulsed laser deposition , 1998 .

[12]  J. Redwing,et al.  Evidence of compensating centers as origin of yellow luminescence in GaN , 1997 .

[13]  Shuji Nakamura,et al.  High‐power InGaN single‐quantum‐well‐structure blue and violet light‐emitting diodes , 1995 .

[14]  L. Dobrzyński,et al.  Observation Of Native Ga Vacancies In Gan By Positron Annihilation , 1997 .

[15]  F. Antoni,et al.  Growth of GaN(0001) thin films on Si(001) by pulsed reactive crossed-beam laser ablation using liquid Ga and N2 , 1998 .

[16]  J. Donegan,et al.  Photoluminescence of localized excitons in pulsed-laser-deposited GaN , 1998 .

[17]  April S. Brown,et al.  Role of sapphire nitridation temperature on GaN growth by plasma assisted molecular beam epitaxy: Part I. Impact of the nitridation chemistry on material characteristics , 2002 .

[18]  H. M. Liaw,et al.  Growth of crack-free hexagonal GaN films on Si(100) , 2001 .

[19]  Toshio Ogino,et al.  Mechanism of Yellow Luminescence in GaN , 1980 .

[20]  M. Döbeli,et al.  Kinetic, crystallographic, and optical studies of GaN and AlxGa1−xN thin films grown on Si(111) by pulsed reactive crossed-beam laser ablation using liquid alloys and N2 or NH3 , 2000 .

[21]  Observation of long photoluminescence decay times for high-quality GaN grown by metalorganic chemical vapor deposition , 2000 .