Study of the growth characteristics of SiCGe layers grown on 6H-SiC substrates

SiCGe layers were grown on 6H-SiC ( 0001) substrates by low pressure hot wall chemical vapor deposition at different temperatures (1100 degrees C-1250 degrees C) and with different GeH4 flow-rate ratios (6.3%-25%). Surface morphology, growth characteristics, and Ge contents of the samples were studied. Results of scan electron microscope images show that the SiCGe layers tend to grow in an island growth mode at lower temperatures, and the growth mode will change to the layer by layer mode accompanied by changes in island form and density as the growth temperature increases. X-ray photoelectron spectroscopy tests show that the Ge contents in the samples are in a range of 0.15 % to 0.62 %, and they increase with the increase of GeH4 flow rates and the decrease of growth temperatures when other growth parameters are kept constant. Additionally, antiphase boundary (APB) defects in the SiCGe layers were analyzed qualitatively.