Electrical Properties of Al/CaF₂/i-Diamond Metal-Insulator-Semiconductor Field-Effect-Transistor Fabricated by Ultrahigh Vacuum Process

Abstract

In order to avoid oxygen contamination on the diamond surface as far as possible during the device process, the diamond metal-insulator-semiconductor field-effect transistor (MISFET) was prepared by a reduced-oxygen process including an ultrahigh vacuum (UHV) process for the first time, and its electrical properties were investigated in detail. According to the results, it was found that the electrical properties of the MISFET were improved to a great extent in comparison with those of conventional diamond MISFETs. The observed effective mobility (µeff) was 400 cm2/V·s at room temperature, which is the highest value obtained until now in the diamond FET at room temperature. Besides, the measured transconductance (g m) and surface state density (N SS) of the device operation region was 5 mS/mm and ∼1010/cm2·eV, respectively, which is also comparable with conventional Si metal-oxide-semiconductor field-effect-transistors (MOSFETs) with the same gate length (L g = 30 µm).

Interfacial band configuration and electrical properties of LaAlO3/Al2O3/hydrogenated-diamond metal-oxide-semiconductor field effect transistors

“…The g m value at the L G of 30 lm is larger than those of the CaF 2 /H-diamond (0.15 mS mm À1 ) and AlN/H-diamond (0.2 mS mm À1 ) FETs with the equivalent L G . 26,45 Figure 7 shows the calculated effective mobility (l eff ) as a function of 2R SD ÁW G at 2R C ( 2R SD and 2R C ( R CH based on the following equation: 46…”

“…The l eff values evaluated are in agreement with those of other MOSFET reported so far. 19,45 IV. DISCUSSIONS…”

Fabrication of Metal–Oxide–Diamond Field-Effect Transistors with Submicron-Sized Gate Length on Boron-Doped (111) H-Terminated Surfaces Using Electron Beam Evaporated SiO2 and Al2O3

“…SiO 2 gate insulators have been investigated as a MISFET on B-doped diamond, 14,15 however, only low transconductance (3.9 lS/mm) was achieved, 16 mainly due to the high resistivity of the B-doped diamond. Yun et al [16][17][18] investigated the surface state density between CaF 2 and a diamond interface and succeeded in decreasing the density to 10 10 /cm 2 eV, which is a sufficiently low level to make CaF 2 an appropriate gate insulator for H-terminated diamond MISFETs. Unfortunately, CaF 2 is not a suitable material, due to its instability at elevated humidity.…”

Electrolyte-Solution-Gate FETs Using Diamond Surface for Biocompatible Ion Sensors

“…The surface carrier density is more than one order of magnitude higher than that of inversion layers of Si MOS interfaces and is comparable to that of AlGaN/GaN interfaces. Using the surface p-type conductivity of hydrogen-terminated surfaces, high performance metal-semiconductor field effect transistors (MESFETs) [8,9] and metal-insulator-semiconductor FETs (MISFETs) [10,11] have been fabricated on homoepitaxial layers. Even in polycrystalline diamond, MESFETs [12] and MISFETs [13] are also reported.…”