M. Gibbon et al., SELECTIVE-AREA LOW-PRESSURE MOCVD OF GAINASP AND RELATED MATERIALS ONPLANAR INP SUBSTRATES, Semiconductor science and technology, 8(6), 1993, pp. 998-1010
Low-pressure MOCVD has been used to grow layers of InP, InGaAs, GaInAs
P and quantum well material on planar substrates patterned with silica
masks. The thicknesses and, where relevant, the compositions of these
selectively grown layers were investigated by optical and scanning el
ectron microscopy, Surface profiling, energy dispersive x-ray analysis
, secondary-ion mass spectroscopy and spatially resolved photoluminesc
ence. The epitaxial layers were found to be both thicker and richer in
indium in the vicinity of a mask. The perturbations in the thickness
and composition of material grown around a given mask pattern were ind
ependent of the orientation of the pattern with respect to the gas flo
w and the crystallographic axes of the substrate. Lateral movement of
material from the masked regions to the surrounding areas was found to
take place in the gas above the wafer surface. A gas-phase diffusion
model based on Laplace's equation was used to analyse the thickness an
d compositional variations caused by selective growth. The emission wa
velength of selectively grown InGaAs/GaInAsP GaInAsP MQW material was
shifted by over 100 nm without degradation in emission efficiency. The
lasing wavelength of Fabry-Perot lasers fabricated on such material w
as increased by a similar amount without degradation of threshold curr
ent.