Sf. Yoon et al., EFFECTS OF SUBSTRATE-TEMPERATURE ON THE PROPERTIES OF IN0.48GA0.52P GROWN BY MOLECULAR-BEAM EPITAXY USING A VALVED PHOSPHORUS CRACKER CELL, Journal of crystal growth, 191(4), 1998, pp. 613-620
We report the molecular-beam epitaxial (MBE) growth of high-quality In
0.48Ga0.52P epitaxial layers on GaAs substrate using a valved phosphor
us cracker cell at a wide range of substrate temperature (T-s) from 44
0 to 520 degrees C. Film characterization was carried out using double
-axis X-ray diffraction (XRD), low-temperature photoluminescence (PL)
and Hall-effect measurement. Typical InGaP layers showed a lattice mis
match of <10(-3) and PL full-width at half-maximum (FWHM) as low as 7
meV at 10 K, indicating materials with good structural and optical qua
lity. The lattice mismatch remained relatively constant for samples gr
own between 440 and 500 degrees C but increased significantly as the s
ubstrate temperature was increased to 520 degrees C. Compositional mea
surements using XRD showed that indium desorption was significant in s
amples grown at substrate temperatures exceeding 500 degrees C. The PL
peak energy decreased from 2.014 +/- 0.008 to 1.968 +/- 0.008 eV as t
he substrate temperature was increased from 440 to 520 degrees C. The
highest PL peak energy of 2.014 +/- 0.008 eV which was indicative of t
he highest band gap was measured from the sample grown at T-s = 440 de
grees C. The results suggest that highly disordered (i.e. random) InGa
P materials can be grown at low substrate temperature with excellent s
tructural and optical quality. (C) 1998 Elsevier Science B.V. All righ
ts reserved.