We investigated the growth temperature dependence of the defect morphologies in the SiGe films grown on Si(110) substrates. The substrate temperature range in this investigation was 700-800 C. The samples were comprised of compositionally graded and uniform layers. A transition in the strain relaxation mechanism from microtwin formation to dislocation generation was newly found, which occurred at 800 C. (C) 2008 Elsevier B.V. All rights reserved.