Abstract
Gallium oxide (Ga2 O3) thin films of various thicknesses were grown on sapphire (0001) substrates by metal organic chemical vapor deposition (MOCVD) using trimethylgallium (TMGa), high purity deionized water, and silane (SiH4) as gallium, oxygen, and silicon precursors, respectively. N2 was used as carrier gas. Hall measurements revealed that films grown with a lower VI/III ratio had a dominant p-type conduction with room temperature mobilities up to 7 cm2 /Vs and carrier concentrations up to ~1020 cm−3 for thinner layers. High resolution transmission electron microscopy suggested that the layers were mainly κ phase. Microstrip field-effect transistors (FETs) were fabricated using 2D p-type Ga2 O3:Si, channels. They achieved a maximum drain current of 2.19 mA and an on/off ratio as high as ~108. A phenomenological model for the p-type conduction was also presented. As the first demonstration of a p-type Ga2 O3, this work represents a significant advance which is state of the art, which would allow the fabrication of p-n junction based devices which could be smaller/thinner and bring both cost (more devices/wafer and less growth time) and operating speed (due to miniaturization) advantages. Moreover, the first scaling down to 2D device channels opens the prospect of faster devices and improved heat evacuation.
Original language | English (US) |
---|---|
Article number | 578 |
Journal | Photonics |
Volume | 8 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2021 |
Funding
This work is supported by USA Air Force under agreement of FA9550-19-1-0410.
Keywords
- Ga O
- MOCVD
- P-type
- Thin films
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Instrumentation
- Radiology Nuclear Medicine and imaging