In this paper, the influence of reactor pressure on the quality of GaN epilayer grown by Hydride vapor phase epitaxy (HVPE) is reported. A series of sample was fabricated at 0.2, 0.5, 0.7 and 1 atm. There were several samples at certain pressure in order to avoid the random affection. And the root mean square (RMS) is introduced to determine the repeatability. The rocking curve and photoluminescence spectrum are used to evaluate the quality of the grown epilayer. The reactor pressure has affection on the quality of GaN epilayer. Low reactor pressure is helpful to improving the quality of crystal structure.
Abstractc-plane (0001) AlN layers were grown on sapphire (11-20) and (0001) substrates by hydride vapor phase epitaxy (HVPE) and metal-organic vapor phase epitaxy (MOVPE), respectively. The growth temperatures were adjusted from 1430-1500 °C and the reactor pressure was kept constant at 30 Torr. Mirror and flat c-plane AlN were obtained grown on both a-plane and c-plane sapphire. Crystalline quality and surface roughness are improved with increasing growth temperature, detected by high resolution X-ray diffraction (HRXRD) and atomic force microscopy (AFM). The Full widths at half maximum (FWHM) values of (10-12) diffraction are 519 and 1219 arcsec for c-plane AlN grown on a-plane sapphire and c-plane sapphire, respectively. It indicates that a-plane sapphire substrate benefits to decrease dislocations density.
Hydride Vapor-Phase Epitaxy of c-Plane AlGaN Layers on Patterned Sapphire Substrates
