Effect of lower growth temperature on C incorporation in GeC epilayers on grown by MBE

Abstract Effect of lower growth temperature T s on C incorporation to substitutional sites in Ge 1−x C x / Si (0 0 1) grown by molecular beam epitaxy was investigated. To enhance the non-equilibrium growth condition, the temperature T s was lowered from 600°C down to 300°C. The C incorporation into substitutional sites of GeC epilayers was very sensitive to T s . X-ray diffraction (XRD) measurement indicated that the substitutional C composition x increased with decrease in T s from 600°C to 400°C. At T s ⩽350°C, the estimation of x by the XRD analysis was impossible because of polycrystallization. The Raman shift measurement enables to estimate x for T s ⩽350°C, as consequently larger x than that grown at T s =400°C was verified. The enhancement of non-equilibrium growth condition by decreasing T s was important to increase x .