Depletion-mode Ga2O3 metal-oxide-semiconductor field-effect transistors on β-Ga2O3 (010) substrates and temperature dependence of their device characteristics

Abstract

Single-crystal gallium oxide (Ga 2 O 3) metal-oxide-semiconductor field-effect transistors were fabricated on a semi-insulating b-Ga 2 O 3 (010) substrate. A Sn-doped n-Ga 2 O 3 channel layer was grown by molecular-beam epitaxy. Si-ion implantation doping was performed to source and drain electrode regions for obtaining low-resistance ohmic contacts. An Al 2 O 3 gate dielectric film formed by atomic layer deposition passivated the device surface and significantly reduced gate leakage. The device with a gate length of 2 lm showed effective gate modulation of the drain current with an extremely low off-state drain leakage of less than a few pA/mm, leading to a high drain current on/off ratio of over ten orders of magnitude. A three-terminal off-state breakdown voltage of 370 V was achieved. Stable transistor operation was sustained at temperatures up to 250 C. V

Heteroepitaxial growth of ε-Ga2O3 thin films on cubic (111) MgO and (111) yttria-stablized zirconia substrates by mist chemical vapor deposition

“…In particular, Ga 2 O 3 exhibits a large bandgap (approximately 5 eV), 8) and its electrical conductivity can be controlled by introducing impurities into its matrix. 9) These properties have paved the way for new applications of this material, such as in the Schottky barrier diode 10) and MOSFET, 11) for next-generation power devices with a higher breakdown voltage than conventional GaN and SiC power devices, solar-blind photodetectors, 12) and flame detectors. 13) Ga 2 O 3 appears in five polymorphs, i.e., α-, β-, γ-, δ-, and ε-phases.…”

Deep level defects in Ge-doped (010) β-Ga2O3 layers grown by plasma-assisted molecular beam epitaxy

“…10,11 However, perhaps the primary driver for the interest is that b-Ga 2 O 3 , with its $4.5-4.9 eV bandgap, 2 is available as a bulk crystal, and therefore, native substrates are available for lattice-matched epitaxial growth of device structures, unlike contemporary wide and ultrawide bandgap semiconductors. In spite of the early stage of development, promising device demonstrations have already been reported, including metal-semiconductor field effect transistors (MESFETs), 1 metal-oxide field effect transistors (MOSFETs), [2][3][4][5] Schottky diodes, [6][7][8][9] FinFETs, 12 delta-doped FETs, 13 and (Al 1-x Ga x ) 2 O 3 /Ga 2 O 3 modulation-doped field effect transistors (MODFETs) grown by plasma-assisted molecular beam epitaxy (PAMBE). 14,15 For these devices to evolve as theoretically predicted, controlled doping during epitaxy is critical and doping studies in b-Ga 2 O 3 are at an early stage for molecular beam epitaxy (MBE) growth.…”

“…[1][2][3][4][5][6][7][8][9][10][11] Interest is also rising for possible applications as a deep ultraviolet solar blind detector due to its outstanding transparency out to $260 nm. 10,11 However, perhaps the primary driver for the interest is that b-Ga 2 O 3 , with its $4.5-4.9 eV bandgap, 2 is available as a bulk crystal, and therefore, native substrates are available for lattice-matched epitaxial growth of device structures, unlike contemporary wide and ultrawide bandgap semiconductors.…”

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.…”