Abstract
The step cooling technique for liquid phase epitaxy was used to grow In 0.75 Ga 0.25 As 0.56 P 0.44 thin films on InP substrates. The optimum growth temperature is 635°C with a supercooling temperature (δT) of 10°C. Under these conditions, the lattice mismatches between epilayers and substrates were less than 0.03% as determined by X-ray diffraction measurements. The solid composition was studied. From optical transmission measurement, the corresponding wavelength of the quaternary layer was 1.28 μ m. The quality of the In 0.75 Ga 0.25 As 0.56 P 0.44 epitaxial layers was studied by using the diffraction patterns from transmission electron microscopy. The measured room temperature mobility and carrier concentration of undoped InGaAsP epilayers were 3200 cm 2 Vh.s and 1.76x10 16 cm -3 , respectively. © 1984.