First demonstration of robust tri-gate-GaOnano-membrane field-effect transistors.

Nano-membrane tri-gate-gallium oxide (-GaO) field-effect transistors (FETs) on SiO/Si substrate fabricated via exfoliation have been demonstrated for the first time. By employing electron beam lithography, the minimum-sized features can be defined with the footprint channel width of 50 nm. For high-quality interface between-GaOand gate dielectric, atomic layer-deposited 15 nm thick aluminum oxide (AlO) was utilized with tri-methyl-aluminum (TMA) self-cleaning surface treatment.

Solar-Blind UV Photodetector Based on Atomic Layer-Deposited CuO and Nanomembrane β-GaO pn Oxide Heterojunction.

Herein, we present a solar-blind ultraviolet photodetector realized using atomic layer-deposited p-type cuprous oxide (CuO) underneath a mechanically exfoliated n-type β-gallium oxide (β-GaO) nanomembrane. The atomic layer deposition process of the CuO film applies bis(,'-di-secbutylacetamidinato)dicopper(I) [Cu(Bu-Me-amd)] as a novel Cu precursor and water vapor as an oxidant. The exfoliated β-GaO nanomembrane was transferred to the top of the CuO layer surface to realize a unique oxide pn heterojunction, which is not easy to realize by conventional oxide epitaxy techniques.

Thermodynamic Studies of β-GaO Nanomembrane Field-Effect Transistors on a Sapphire Substrate.

The self-heating effect is a severe issue for high-power semiconductor devices, which degrades the electron mobility and saturation velocity, and also affects the device reliability. On applying an ultrafast and high-resolution thermoreflectance imaging technique, the direct self-heating effect and surface temperature increase phenomenon are observed on novel top-gate β-GaO on insulator field-effect transistors. Here, we demonstrate that by utilizing a higher thermal conductivity sapphire substrate rather than a SiO/Si substrate, the temperature rise above room temperature of β-GaO on the insulator field-effect transistor can be reduced by a factor of 3 and thereby the self-heating effect is significantly reduced.