Technologies for Low Power Density Phased Array Radars

This Phase-I SBIR Army Proposal proposes the use of a new class of diamond-seeded solid-state material system for the manufacture of virtually all heat-generating solid-state electronics in X-band and Ballistic Missile Defense radar components and systems. In this proposal wherein much preliminary (DARPA-funded) work has already been demonstrated by the authors, all or most of the basic semiconductor devices in an electronic RF unit (e.g. GaN HEMTs, Power Amplifiers, etc.) are replaced with Semiconductor-on-Diamond based devices to enable nearly total and immediate heat extraction from the device's active region. Gallium Nitride-on-Diamond will be implemented here. Polycrystalline free standing CVD diamond - nature's most efficient thermal conductor - enables nearly perfect heat extraction from a "hot" device, owing to the extreme thermal conductivity of diamond (GaAs, Si, and SiC are 35W/m/K, 150W/m/K and 390W/m/K respectively; diamond ranges from 1200-2000 W/m/K depending on quality). In the proposed scheme, the device's active epitaxial layers are removed from their original host substrate and transferred on to a specially treated low-cost CVD diamond substrate using a proprietary low-cost manufacturable scheme. The semiconductor-on-diamond technology proposed here may be applied to Si, GaAs, GaN, SiC, SiGe, etc. at up to 8" in wafer diameter.