Channeling studies of relaxed, epitaxial Si 1− xGe x films

Abstract

<100>-axial and (110)-planar channeling studies of relaxed, epitaxial Si 1− x Ge x (100) films have been performed for 0≤ x ≤ 0.37. The films were grown by MBE on graded buffer layers by the compositional grading technique and had threading dislocation densities ≤ 10 6 cm −2. The <100>-axial and (110)-planar angular dependencies of the backscattered yield for samples with different compositions revealed a significant increase in the normalized minimum yield, X min, for increasing Ge concentration in conflict with a linear interpolation between values for Si and Ge; the values of the angular half-width, Ψ ½, were in agreement with an interpolation between values for Si and Ge. An explanation of the observed effects is given.