Improvement of Surge Protection by Using an AlGaN/GaN-Based Metal–Semiconductor–Metal Two-Dimensional Electron Gas Varactor

Abstract

In this paper, a varactor with metal-semiconductor-metal diodes on top of the (NH 4 ) 2 S/P 2 S 5 -treated AlGaN/GaN two-dimensional electron gas epitaxial structure (MSM-2DEG) is proposed to the surge protection for the first time. The sulfur-treated MSM-2DEG varactor properties, including current-voltage (I-V ), capacitance-voltage (C-V ), and frequency response of the proposed surge protection circuit, are presented. To verify its capability of surge protection, we replace the metal oxide varistor (MOV) and resistor (R) in a state-of-the-art surge protection circuit with the sulfur-treated MSM-2DEG varactor under the application conditions of system-level surge tests. The measured results show that the proposed surge protection circuit, consisted of a gas discharge arrester (GDA) and a sulfur-treated MSM-2DEG varactor, can suppress an electromagnetic pulse (EMP) voltage of 4000 to 360 V, a reduction of 91%, whereas suppression is to 1780 V, a reduction of 55%, when using only a GDA.

GaN 2DEG Varactor-Based Impulse Suppression Module for Protection Against Malicious Electromagnetic Interference

“…On the other hand, two-dimensional electron gas (2DEG) metal-semiconductor-metal (MSM)-structured varactors, which are GaN-or GaAs-based wide-band-gap compound semiconductor devices with very short reaction times, 12 are highly compatible. By connecting GaN-based 2DEG varactors with an ''in series'' form, shunt capacitance is no longer a problem, thus benefiting high-frequency applications.…”