High-temperature (350 °C) oxidized iridium Schottky contacts on β -Ga2O3

Abstract

Oxidized iridium (IrOx) Schottky contacts (SCs) with excellent high temperature stability were fabricated on 2¯01 β-Ga2O3 single crystal substrates. These IrOx:β-Ga2O3 SCs were operated at temperatures from 24 to 350 °C with only a very small increase in reverse leakage current, while maintaining extremely high rectification ratios (at ±3 V) of more than 10 orders of magnitude at all temperatures, including 350 °C. This remarkable high temperature performance was due to their very high and thermally stable rectifying barriers that, after an initial heat-related improvement, were characterized by zero-bias effective barrier heights of 2.05 ± 0.02 eV and ideality factors of 1.05–1.10, which were almost unchanged by further repeated operation at 350 °C. The reverse leakage current density at 350 °C was only ∼2.3 × 10−9 A cm−2 (∼3.0 pA) at −3 V and ∼7.5 × 10−8 A cm−2 (∼100 pA) at −100 V. These IrOx:β-Ga2O3 SCs represent a significant improvement in high-temperature β-Ga2O3 SC performance, with considerable potential for the fabrication of high temperature β-Ga2O3 rectifying diodes, deep UV photodetectors, and metal-semiconductor field effect transistors.

Accelerated Aging Stability of β-Ga2O3–Titanium/Gold Ohmic Interfaces

“…To ensure reliable power electronics, it is critical to assess the interface stability under such conditions. To address this need, recent works have demonstrated Schottky diodes with barriers of >1.8 eV that operate up to 350 °C. , Such devices exploit the position of the charge neutrality level, which is located ∼0.6 eV below the conduction band minimum in n-type β-Ga 2 O 3 , causing upward band bending at the surface, enabling facile formation of rectifying Schottky contacts. However, the same phenomena may make the formation of ohmic contacts to β-Ga 2 O 3 more challenging.…”

High‐Quality Si‐Doped β‐Ga2O3 Films on Sapphire Fabricated by Pulsed Laser Deposition

“…PLD of Ga 2 O 3 has been demonstrated previously and most of these early references primarily investigate the material quality of β-Ga 2 O 3 deposited on Al 2 O 3 . [3][4][5][6] Later, pulsed laser deposited β-Ga 2 O 3 on Al 2 O 3 has also been used for demonstrating device applications, such as solar-blind UV detectors [7,8] and Schottky diodes, for instance, with Cu, [9] Ni, [10] and Ir [11] contacts. Silicon, a common impurity in Ga 2 O 3 grown from melt, has been shown to be acting as a donor and contribute to the n-type character of substrates, presumably residing on substitutional Ga sites.…”

High Performance β‐Ga2O3 Schottky Barrier Transistors with Large Work Function TMD Gate of NbS2 and TaS2

“…[27] Less leakage current, control of larger channel thickness, smaller subthreshold swing (SS) and smaller V th may come out as benefits due to their larger Schottky barrier. [2,[28][29][30] Our MESFETs show minimum SS and V th values of 61 mV dec −1 and −1.2 V, respectively, along with minimum OFF drain current (I D ) of ≈100 fA and maximum ON/OFF current ratio of ≈10 8 . A MESFET with TaS 2 gate is thus integrated as a switching FET into a green organic light emitting diode (OLED) pixel circuit with two transistors and one storage capacitor, to demonstrate its long-term leakage endurance performance.…”