Inversion in Metal–Oxide–Semiconductor Capacitors on Boron-Doped Diamond

In this letter we report the first diamond fin field-effect transistor (diamond FinFET) without a hydrogen-terminated channel. The device operates with hole accumulation by metal-oxide-semiconductor (MOS) structures built on fins to maintain effective control of the channel conduction. Devices with 100-nm—wide fins were designed and fabricated to ensure that the channel pinched off at zero gate bias. The transfer characteristic of FinFET showed a greater than 3000 on/off ratio, successfully demonstrating the transistor behavior. Devices were characterized at room temperature and at 150 °C, showing 30 mA/mm current density at 150 °C, 35 times more than current density at room temperature. The diamond FinFET, which leverages the fin concept from the silicon industry and the material advance of diamond, enables a new class of diamond transistors for applications from digital to power and radio frequency (RF) electronics.

Section: Discussionsupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Diamond FinFET without Hydrogen Termination

Huang

Bai

Lam

et al. 2018

“…1(b)-2 ]. The aluminium oxide (Al 2 O 3 ) gate insulator layer which has been used for the fabrication of high-performance diamond MOS devices in the previous reports 14 15 28 and the aluminium (Al) gate electrode were then deposited to cover the entire sample surface by atomic layer deposition (ALD) and ultra-high-vacuum (UHV) sputtering techniques, respectively [ Fig. 1(b)-3 ].…”

Section: Resultsmentioning

confidence: 99%

Design and fabrication of high-performance diamond triple-gate field-effect transistors

Liu

Ohsato

Wang

et al. 2016

The lack of large-area single-crystal diamond wafers has led us to downscale diamond electronic devices. Here, we design and fabricate a hydrogenated diamond (H-diamond) triple-gate metal-oxide-semiconductor field-effect transistor (MOSFET) to extend device downscaling and increase device output current. The device’s electrical properties are compared with those of planar-type MOSFETs, which are fabricated simultaneously on the same substrate. The triple-gate MOSFET’s output current (174.2 mA mm−1) is much higher than that of the planar-type device (45.2 mA mm−1), and the on/off ratio and subthreshold swing are more than 108 and as low as 110 mV dec−1, respectively. The fabrication of these H-diamond triple-gate MOSFETs will drive diamond electronic device development forward towards practical applications.

“…Therefore, the realization of diamond MOSFETs with an inversion channel is a long-standing research topic. Although diamond MOS capacitors with boron-doped p-type diamond bodies have been reported 21 22 23 24 25 , the inversion channel diamond MOSFETs have not yet been reported. Here, we fabricated diamond MOSFETs with a phosphorus-doped n-type diamond body by wet annealing for controlling the MOS interface.…”

mentioning

confidence: 99%

Inversion channel diamond metal-oxide-semiconductor field-effect transistor with normally off characteristics

Matsumoto

Kato

Oyama

et al. 2016

166

We fabricated inversion channel diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) with normally off characteristics. At present, Si MOSFETs and insulated gate bipolar transistors (IGBTs) with inversion channels are widely used because of their high controllability of electric power and high tolerance. Although a diamond semiconductor is considered to be a material with a strong potential for application in next-generation power devices, diamond MOSFETs with an inversion channel have not yet been reported. We precisely controlled the MOS interface for diamond by wet annealing and fabricated p-channel and planar-type MOSFETs with phosphorus-doped n-type body on diamond (111) substrate. The gate oxide of Al2O3 was deposited onto the n-type diamond body by atomic layer deposition at 300 °C. The drain current was controlled by the negative gate voltage, indicating that an inversion channel with a p-type character was formed at a high-quality n-type diamond body/Al2O3 interface. The maximum drain current density and the field-effect mobility of a diamond MOSFET with a gate electrode length of 5 μm were 1.6 mA/mm and 8.0 cm2/Vs, respectively, at room temperature.