Diamond wafer in inverter consisted of high mobility and low on-resistance MISFETs

Hydrogenated diamond (C- H diamond) inverters have been fabricated by normally-off Al/BaF2/C-H diamond metal-insulator-semiconductor field effect transistors (MISFETs) and load resistors. Electron beam evaporation was used to deposit BaF2 film on the diamond surface at room temperature to reduce the thermal degradation effect on the C- -H bond and adsorbates during the deposition. The resulting 4-μm normally-off MISFET achieves the maximum saturation drain current, on-resistance, maximum transconductance, and switching ratio of - 113.4 mA/mm, 37.1 9:mm, 35.4 mS/mm, and 10, respectively. Effective hole mobility of more than 200 cm2/V.s is achieved in a large gate voltage range (-0.35 V≤VGs -VTH≤-4.35 V). Correspondingly, based on the high-performance diamond MISFET, the diamond inverters exhibit good voltage transfer characteristics and dynamic switching characteristics at the frequency of 50 kHz.

In recent years, C- H diamond-based FET and inverter research have received continuous attention and made a series of breakthroughs. At present relevant studies have confirmed that two-dimensional hole gas (2DHG) can be produced on the hydrogenated diamond (C- H diamond) surface, which has strongly promoted the development of diamond FETs. By treating diamonds in a hydrogen plasma atmosphere, C- H bonds can be formed on the surface of the diamond, which accumulates holes near the surface and becomes conductive ]. The adsorbed species that induce an increase in the hole concentration on the surface of the C- - -H diamond are air, NO2, and solid-state surface acceptors, such as MoO3   and V2Os. The concentration and mobility of the 2DHG are usually 1012— 1014cm-2 and 10-300 cm2/Vs.

Diamond has a wide bandgap (5.47 eV) and the highest thermal conductivity (22 W/cmK). Notably, with high carrier mobility and carrier saturation velocity, diamond is also promising for the fabrication of high-performance field effect transistors (FETs) and logic circuits for high-speed and low-loss switching operations.

Compound Semiconductor (Xiamen) Technology Co., Ltd is a wide bandgap Semiconductor Material company invested from   Korea, China, and Singapore, registered in the city of Xiamen, China.We are equipped with advanced semiconductor manufacturing tools including MPCVD, MOCVD, LPCVD, HVPE, and high temperature PVD.Products include high quality diamond wafer, diamond heat sink, GaN & Diamond wafers, and PVD AlN template etc.

We have a strong R&D team and actively collaborate with the best research groups around the world. Currently, we are providing the thermal grade polycrystalline diamond, which can be used as an effective heat sink and aims to solve the heat issue in temperature-sensitive devices, such as power devices, lasers, avalanche photodiodes, etc. We also provide wafer scale polished diamond with sub-nanometer RMS surface roughness, which might be suitable for the integration of GaN, Gao and AlN epilayers and devices on Diamond via direct bonding or heteroepitaxy.