Material growth and device characterization of AlGaN/GaN single-heterostructure and AlGaN/GaN/AlGaN double-heterostructure field effect transistors on Si substrates

摘要

An Al_(0.2)Ga_(0.8)N/GaN/Al_(0.1)Ga_(0.9)N double-heterostructure field effect transistor (DH-FET) structure was grown on a 150-mm-diameter Si substrate and the crystalline quality of the epitaxial material was found to be comparable to that of an Al_(0.2)Ga_(0.8)N/GaN single-heterostructure field effect transistor (SH-FET) structure. The fabricated DH-FET shows a lower buffer leakage current of 9.2 × 10~(-5)mA/mm and an improved off-state breakdown voltage of higher than 200 V, whereas the SH-FET shows a much higher buffer leakage current of 6.0 × 10~(-3)mA/mm and a lower breakdown voltage of 130 V. These significant improvements show that the Al_(0.2)Ga_(0.8)N/GaN/Al_(0.1)Ga_(0.9)N DH-FET is an effective structure for high-power electronic applications.