Effects of annealing temperature on amorphous GaN films formed on Si(1 1 1) by pulsed laser deposition

Abstract

GaN thin films were grown on Si(1 1 1) substrates using a pulsed KrF excimer laser-deposition system, and post-annealing was examined to improve the films' quality. In order to investigate the effect of thermal annealing temperature on the crystalline quality, optical properties and surface morphology of the samples, after deposition, the samples were subsequently annealed at different temperatures in ammonia (NH 3 ) ambience for 15 min. The annealed films were characterized by x-ray diffraction (XRD), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), Raman spectra and photoluminescence spectra. The measured results show that annealing temperature plays an important role in improving the quality of GaN films, polycrystalline wurtzite structure GaN thin films with c-axis preferred orientation were successfully obtained by annealing, and the optimum annealing temperature is 1100 • C.

Structural Characteristics and Photoluminescence Properties of Sputter-Deposition ZnGa2O4 Thin Films on Sapphire and Si(100) Substrates

“…The grain sizes of ZnGa 2 O 4 (111) deposited on sapphire and Si(100) were thus estimated as 27.43 and 16.43 nm, respectively. The FWHM of XRD diffraction peak is relative to the average grain size in the film [21]. Since the substrate temperature level of 600 • C showed a better crystalline quality as evidenced by XRD analysis, we only focused on the 600 • C samples in the following work (SEM, TEM, and PL).…”

Optoelectronic Properties and Structural Characterization of GaN Thick Films on Different Substrates through Pulsed Laser Deposition

“…However, the XRD peak intensity increases as FWHM decreases; this is attributed to the increase in the crystallite size due to either the aggregation of small grains or grain boundary movement during the growth process. Since the FWHM of the XRD diffraction peak is relative to the average crystallite grain size in the film [26], the grain size of GaN grown on the different substrates is calculated using the Debye-Scherer equation [27]:…”

Electrodeposition of gallium in the presence of NH4Cl in an ionic liquid: hints for GaN formation

“…Such broad peak in amorphous GaN was reported recently. 23 We also compared the XRD pattern with commercially available GaN (99.99% purity) from Sigma-Aldrich (green line, Fig. 4).…”