High performance AlGaN/GaN power switch with HfO2 insulation

Abstract

High performance AlGaN/GaN metal-insulator-semiconductor heterostructure field-effect transistor was fabricated using HfO2 as the surface passivation and gate insulator. The gate and drain leakage currents are drastically reduced to tens of nanoamperes before breakdown. Without field plates, for 10 μm of gate-drain spacing, the off-state breakdown voltage is 1035 V with a specific on resistance of 0.9 mΩ cm2. In addition, there is no current slump observed from the pulse measurements. This is the best performance reported on GaN-based power-switching devices on sapphire up to now, which efficiently combines excellent device forward, reverse, and switching characteristics.

Wafer scale and reliability investigation of thin HfO2·AlGaN/GaN MIS-HEMTs

“…The device width (W) was 150 lm. constant ($20) which make this gate insulator very effective in realizing HEMT devices with a large transconductance while keeping the gate leakage current low [3]. The introduction of a gate insulator affects somehow the Schottky operation of the i-HEMTs, since the parallel capacitance association of the gate oxide and the AlGaN buffer diminishes the gate capacitance.…”

“…Hafnium oxide (HfO 2 ) has recently been demonstrated as a very promising gate dielectric candidate for GaN-based highpower RF and high-voltage switches. Transistors with HfO 2 gate insulator have already exhibited minimal current slump, low onresistance, high breakdown voltage, and ultra-low leakage currents [3][4][5][6].…”

Reverse current thermal activation of AlGaN/GaN HEMTs on Si(111)

“…It is worth to mention that neither the GaN buffer nor the AlGaN was not optimized for very high voltage operation. It can be achieved, for example, by the use of AlGaN back barriers, optimization of the AlN barrier or gate dielectric passivation [1][2][3][4]. As shown in Fig.…”

“…Besides, a large conduction band discontinuity together with the presence of polarizations fields on GaN based heterojunctions allow a large two-dimensional electron gas (2DEG) concentration to be confined. This results in high electron mobility transistors (HEMTs) offering a virtually unbeatable on-resistance vs breakdown voltage trade-off [1][2][3][4][5]. Therefore the AlGaN/GaN HEMT is currently considered as one of the most promising power device switch with great potential for many applications requiring high frequency, high voltage, and high temperature such as power supplies and motors [6].…”

The structural and optical properties of selectively grown a-plane GaN with LT-GaN and HT-AlN buffer layers

“…III-nitride based semiconductors, such as Ga-In-Al-N alloys, have attracted attention for their potential in high power, high temperature devices and optical devices grown on heterosubstrates [1][2][3]. In general, epitaxial growth along c-axis GaN produces undesirable internal electric fields due to strong spontaneous and piezoelectric polarization fields, which limit the performance of opto-electric devices.…”