PULSED LASER EVAPORATION AND EPITAXY OF CD1-XMNXTE

A high vacuum deposition system with laser induced vapors, pulsed laser evaporation and epitaxy (PLEE), has been applied for the epitaxial growth of Cd1-xMnxTe (0<x≤0.70). Two lasers were used for simultaneous evaporation of high-purity targets. A XeCl excimer laser, operating at the wavelength of 0.308 μm and triggered at a rate of up to 80 Hz, vaporized Cd1-xMnxTe ta ets. A Nd: YAG laser, which was triggered at a rate between 0.5 and 5 kHz, was used to generate at Cd flux up to 1016 atoms/cm2·s. The layers were grown on the B face of (111)GaAs substrates held at a fixed temperature in the range of 210-310°C. In-situ reflection high-energy electron diffraction, scanning electron microscopy, energy-dispersive X-ray analysis and low-temperature photoluminescence (PL) revealed that layers of molecular beam epitaxy quality have been routinely grown. A sharp feature (FWHM = 9.5 meV) due to neutral-acceptor bound-exciton recombination is observed at 1.719 eV for a 1.0 μm thick Cd0.921Mn0.079Te layer. We believe that this result represents one of the best Cd1-xMnxTe layers yet grown on GaAs. The origin of a broad band observed near 1.51 eV is discussed. It is argued that this band is due to states related to the presence of Mn in the vicinity of a heavily defective CdMnTe/GaAs interface. © 1989.