Development of gallium oxide power devices

Abstract

Gallium oxide (Ga2O3) is a strong contender for power electronic devices. The material possesses excellent properties such as a large bandgap of 4.7–4.9 eV for a high breakdown field of 8 MV cm−1. Low cost, high volume production of large single‐crystal β‐Ga2O3 substrates can be realized by melt‐growth methods commonly adopted in the industry. High‐quality n‐type Ga2O3 epitaxial thin films with controllable carrier densities were obtained by ozone molecular beam epitaxy (MBE). We fabricated Ga2O3 metal‐semiconductor field‐effect transistors (MESFETs) and Schottky barrier diodes (SBDs) from single‐crystal Ga2O3 substrates and MBE‐grown epitaxial wafers. The MESFETs delivered excellent device performance including an off‐state breakdown voltage (Vbr) of over 250 V, a low leakage current of only few μA mm−1, and a high drain current on/off ratio of about four orders of magnitude. The SBDs also showed good characteristics such as near‐unity ideality factors and high reverse Vbr. These results indicate that Ga2O3 can potentially meet or even exceed the performance of Si and typical widegap semiconductors such as SiC or GaN for ultrahigh‐voltage power switching applications.

Origin of Point Defects in β-Ga2O3 Single Crystals Doped with Mg2+ Ions

“…Recently, metal semiconductor eld-e ect transistor (MESFETs) [1,2], metal oxide semiconductor elde ect transistor (MOSFETs) [1,3] and the Schottky barrier diode (SBDs) [4,5] based on β-Ga 2 O 3 were produced.…”

Electronic properties of the residual donor in unintentionally doped β-Ga2O3

“…The metal-semiconductor field-effect transistors (MESFETs), 4,5 metal-oxide-semiconductor FETs (MOSFETs) 6 and Schottky barrier diodes (SBDs) have recently been demonstrated. 5,7,8 Theoretical calculations predicted that substitutional Si, Ge, Sn, F, and Cl impurities and H (in both substitutional and interstitial sites) have low formation energies and act as shallow donors in β-Ga2O3. 9 Successful n-doping studies have so far been reported for Sn 7,10,11 and Si 12,13 where electron densities in the range of 10 16 -10 19 cm -3 can be achieved.…”

Lattice dynamics of a mist-chemical vapor deposition-grown corundum-like Ga2O3 single crystal

“…6 The monoclinic b-phase is thermodynamically the most stable phase at ambient conditions. 7 Owing to its unique physical properties, such as chemical and thermal stability at high temperatures, large bandgap (E g ¼ 4.9 eV), large breakdown field (estimated at 8 MV cm À1 ), and high dielectric constant ($10) 8,9 as well as to its widely tunable conductivity, 10 a great effort has been devoted in the past decade to the development of b-Ga 2 O 3 -based device technology. Ga 2 O 3 is a promising material to realize low-cost power devices outperforming those based on GaN or SiC.…”