Two-step growth of Cd_0.96Zn_0.04Te/Si(111) epilayers by HWE

High quality Cd_1-xZn_xTe, x = 0.04 epilayers are successfully grown directly on hydrogen-terminated Si(111) substrates by hot wall epitaxy method. Growth conditions are optimized in order to grow single crystal films with desired composition. It is found that surface morphology of the epilayers is dramatically affected by the growth temperature and the growth rate at the early stage of the crystal growth. Applying limited high substrate temperature of T_sub = 440 °C and low growth rate of 0.04 μm/h, the crystallinity is significantly improved and for the first time a pseudomorphic 2D growth is observed notwithstanding of the large lattice mismatch. Designing a suitable two-step growth process makes it possible that Cd_1-xZn_xTe/Si(111), x = 0.04 epilayers are fabricated with good surface morphology, which could be used as lattice matched substrates for MCT and MCZT epitaxy.