Techniques are disclosed for converting a strain-inducing semiconductor buffer layer into an electrical insulator at one or more locations of the buffer layer, thereby allowing an above device layer to have a number of benefits, which in some embodiments include those that arise from being grown on a strain-inducing buffer and having a buried electrical insulator layer. For instance, having a buried electrical insulator layer (initially used as a strain-inducing buffer during fabrication of the above active device layer) between the Fin and substrate of a non-planar integrated transistor circuit may simultaneously enable a low-doped Fin with high mobility, desirable device electrostatics and elimination or otherwise reduction of substrate junction leakage. Also, the presence of such an electrical insulator under the source and drain regions may further significantly reduce junction leakage. In some embodiments, substantially the entire buffer layer is converted to an electrical insulator.