Growth and characterization of thick GaN layers with high Fe doping

Thick Fe-doped GaN layers were grown by metalorganic hydrogen chloride vapor phase epitaxy (MOHVPE). FeCl₂ formed by the reaction between ferrocene (Cp₂Fe) and HCl was introduced during GaN growth. Resistivity of the GaN layer increased with increasing Cp₂Fe input partial pressure. A semi-insulating (SI)-GaN layer exhibiting room-temperature resistivity of 3.0 × 10⁹ Ω cm was successfully prepared by compensating for the residual donors. The crystalline quality of the GaN layer was found to deteriorate with excess Fe doping. These results indicate that control of background donor impurities is critically important to grow high-quality SI-GaN layers. ° 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.