State-of-the-Art AlGaN/GaN-on-Si Heterojunction Field Effect Transistors with Dual Field Plates

Abstract

We have demonstrated state-of-the-art characteristics of AlGaN/GaN-on-Si heterojunction field effect transistors (HFETs) employing dual field plates. Both gate and drain field plate lengths were optimized in order to maximize the breakdown voltage. Great care was taken not only to optimize the field plate lengths but also to develop processing technologies such as mesa-first prepassivation, a recessed ohmic contact, and a sloped gate. A breakdown voltage of 1590 V with a specific on-resistance of 1.86 m cm 2 was achieved for the gate-to-drain distance of 15 m in which the gate and drain field plate lengths were 2 and 1 m, respectively. #

Normally-Off Operation of AlGaN/GaN Heterojunction Field-Effect Transistor with Clamping Diode

“…low on-resistance) and higher threshold voltage can be achieved with easy device processing. The prototype device exhibited an on-resistance of 1.61 mΩ×cm 2 …”

“…Due to the excellent material characteristics such as high breakdown field and high mobility, GaN has been receiving great attention for a next generation power semiconductor with high conversion efficiency and fast switching speed [1,2]. In addition, the strong polarization effects at AlGaN/GaN heterojunction interface create a two-dimensional electron gas channel with very high carrier concentration.…”

Temperature-Dependent Instabilities of DC characteristics in AlGaN/GaN-on-Si Heterojunction Field Effect Transistors

“…A Si/Ti/Al/Mo/Au (= 5/20/60/35/50 nm) metal stack was evaporated and alloyed by a two-step annealing process at 800℃ for 30 sec and 820℃ for 30 s. The following patterning process defined gate regions and a Ni/Pt/Au (= 20/20/100 nm) metal stack was evaporated for Schottky gate contact [9]. A post RTA annealing was carried at 400℃ for 5 min in N 2 ambient to decrease the gate leakage current, which was attributed to the increase in Schottky barrier height [10,11].…”

Diode Embedded AlGaN/GaN Heterojuction Field-Effect Transistor

“…AlGaN/GaN heterojunction field-effect transistors (HFETs) are great candidates for next generation power switching applications in various power electronics due to superior physical properties such as high mobility, high breakdown field, and high carrier concentration [1][2][3][4][5]. In order to fulfill the maximum power conversion efficiency of AlGaN/GaN based power devices, the parasitic effects such as parasitic inductance caused by interconnection between devices must be minimized [6].…”