Radiation effect of X-ray with 100 kGy dose on the electrical properties of MESFET based on hydrogen-terminated diamond surface conductivity

Abstract

The irradiation effect of X-ray on the electrical properties of Schottky-barrier diode (SBD) and metal-semiconductor field-effect transistors (MESFET) based on the surface conductivity of hydrogen-terminated single-crystal diamond (SCD) epilayers was investigated. The Ohmic contact was formed by a Pd/Ti/Au multilayer and the Schottky metal was Al thin film for the fabrication of the diamond SBDs and MESFETs. The X-ray irradiation was performed with a dose of 100 kGy. It was observed that both the forward current of the SBDs and the drain current of the MESFETs experienced a reduction after the X-ray irradiation. The type of the single-crystal diamond substrate had an obvious effect on the radiation properties. For the MESFETs on the type-Ib SCD substrate, the variation of the drain currents as the irradiation was inhomogeneous across the devices. For the MESFETs on the type-IIa SCD substrate, the reduction of the drain currents is more uniform and the threshold voltage changed little upon X-ray irradiation. The partial oxidation in the air of the exposure area in the device and the edge of the Al gate may be responsible for the degradation of the device performance under X-ray irradiation. The passivation technique with radiation-robustness is needed for diamond devices based on the surface conductivity of diamond.

Keywords:

• Single-crystal diamond
• radiation
• surface conductivity
• metal-semiconductor field-effect transistor

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was partially supported by the Innovative Nuclear Research and Development Program (Grant Number 16815754), JSPS KAKENHI (Grant Number 20H02212, 15H03999), and Science and Nanotechnology Platform projects sponsored by the Ministry of Education, Culture, Sports, and Technology (MEXT) of Japan.

Notes on contributors

Mingchao Yang

Dr. Mingchao Yang is now a lecturer in Hebei Normal University of Science and Technology, China. He received the doctor degree in physics science in Jilin University, China in 2019. His research includes diamond electronic devices and electrochemistry.

Takehiro Shimaoka

Dr. Takehiro Shimaoka is now a researcher in National Institute of Advanced Industrial Science and Technology (AIST), Japan. His research interest includes diamond growth and electronics.

Liwen Sang

Dr. Liwen Sang is an independent researcher in International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Japan. Her research interest includes the growth of wide-bandgap III-nitride semiconductors and semiconductor devices.

Junichi H. Kaneko

Dr. Junichi H. Kaneko is now an associate professor in Hokkaido University, Japan. His research interest includes diamond growth and nuclear physics.

Satoshi Koizumi

Dr. Satoshi Koizumi is now a group leader in National Institute for Materials Science (NIMS), Japan. His research interest includes diamond growth and n-type doping of diamond.

Meiyong Liao

Dr. Meiyong Liao is now a chief researcher in National Institute for Materials Science (NIMS), Japan. His research interest includes wide bandgap semiconductor materials (mainly diamond), photonic and electronic devices, MEMS/NEMS, and device physics.