Methods and apparatuses for forming a device structure including a high-thermal-conductivity substrate are disclosed herein. A method forming such a device structure may comprise forming an active layer over a first substrate in a manner such that a frontside of the active layer faces the first substrate and a backside of the active layer faces away from the first substrate, forming a second substrate over the backside of the active layer, and removing the first substrate to expose the frontside of the active layer. Other embodiments are described and claimed.