Hx. Wang et al., Growth of GaN layer by metal-organic chemical vapor deposition system witha novel three-flow reactor, J CRYST GR, 218(2-4), 2000, pp. 148-154
For the first time, this paper reports a novel kind of three-flow reactor w
hich can be developed for metal-organic chemical vapor deposition (MOCVD) s
ystem to grow GaN-based structures. Two parallel carrier gas-flow for Group
-In sources and NH3 separated by a quartz plate which are also parallel to
the substrate are used. The N-2, which is used as a sub-flow, flows through
a quartz filter perpendicular to the substrate where it meets the two para
llel group In and group V source Rows. This new flow arrangement enhances t
he mixture of group III-V sources at the contacting substrate, compared wit
h the previous three parallel laminar gas MOCVD systems due to the perpendi
cular direction of the N-2 sub-flow. Based on this MOCVD system with this s
pecial configuration, a mirror-like epitaxial GaN layer on sapphire substra
te is obtained with an excellent uniformity. Also, the quality of the GaN l
ayers are characterized by room temperature photoluminescence (PL) and X-ra
y diffraction (XRD) measurements, where the full-width at half-maximum (FWH
M) of 41.12 meV for PL spectra and FWHM of about 220 arcsec for XRD racking
curve were measured, respectively. In addition, the carrier concentration
and Hall mobility are found to be 2.6 x 10(17)/cm(3) and 300 cm(2)/V s, res
pectively. (C) 2000 Elsevier Science B.V. All rights reserved.