Abstract: According to one embodiment, a group III-V semiconductor device comprises a compositionally graded body disposed over a substrate and below a buffer layer supporting an active area of the group III-V semiconductor device. The compositionally graded body includes a first region applying compressive stress to the substrate. The compositionally graded body further includes a stress modulating region over the first region, where the stress modulating region applies tensile stress to the substrate. In one embodiment, a method for fabricating a group III-V semiconductor device comprises providing a substrate for the group III-V semiconductor device and forming a first region of a compositionally graded body over the substrate to apply compressive stress to the substrate. The method further comprises forming a stress modulating region of the compositionally graded body over the first region, where the stress modulating region applies tensile stress to the substrate.