Growth of Ge<i>x</i>Si1−<i>x</i> alloys on Si(110) surfaces

Abstract

We have studied the growth of GexSi1−x alloys on Si(110) surfaces. For this growth normal, there are only two inclined {111} glide planes intersecting the interfacial plane. Both intersections are along the same in-plane [11̄0] direction, thus classic a/2〈110〉{111} glide misfit dislocations can form along only one interfacial direction. This produces an orthorhombic unit cell following strain relaxation by misfit dislocations. At sufficiently high stresses, previously unobserved misfit dislocation structures are activated. The critical thickness for misfit dislocation introduction is found to be shifted to lower Ge compositions with respect to growth on the (100) surface, consistent with a higher angular factor resolving the interfacial component of the dislocation Burgers vector in the (110) system.