Enhancement-mode AlGaN/GaN HEMTs with high linearity fabricated by hydrogen plasma treatment

Abstract

Enhancement-mode (E-mode) AlGaN/GaN high electron mobility transistors (HEMTs) are highly desirable for power and digital electronic circuits. Several technologies have been demonstrated in the last few years to fabricate E-mode devices. For example, gate recess can be applied to conventional AlGaN/GaN HEMTs to achieve E-mode operation. However, these devices have very low threshold voltage and large gate leakage. Alternatively, the use of CF[subscript 4] plasma treatment in the gate region prior to gate metallization resuIts in E-mode AlGaN/GaN HEMTs with higher threshold voltage. In this paper, we demonstrate E-mode AlGaN/GaN HEMTs by hydrogen plasma treatment. The results are compared to the F-treated HEMTs an d depletion-mode (D-mode) HEMTs and important differences have been found in the linearity of these transistors.