Insulating GaN:Zn layers grown by hydride vapor phase epitaxy on SiC substrates

Fabrication of high-performance GaN microwave devices, which are the excellent candidates for new generation of high-power solid-state components, requires insulating GaN substrate materials. Due to lack of bulk GaN crystals and particularly lack of semi-insulating GaN substrates, we propose insulating GaN layers on silicon carbide as substrates for the fabrication of GaN-based microwave devices. In this work, we demonstrate insulating GaN layers on silicon carbide substrates. Insulating GaN layers doped with zinc were grown on silicon carbide substrates by hydride vapor phase epitaxy. High crystal quality of the grown material was proved by x-ray diffraction measurements showing the full width at a half maximum of omega-scan rocking curve of about 100 arcsec. Temperature dependence of specific resistivity of the GaN:Zn layers was measured in the temperature range from 200 to 500 K. The value of the specific resistivity was found to be 10(12) Ohm cm at 300 K and 10(9) Ohm cm at 500 K. (C) 1999 American Institute of Physics. [S0003-6951(99)03446-4].