High-mobility p-channel wide-bandgap transistors based on hydrogen-terminated diamond/hexagonal boron nitride heterostructures

Hydrogen-Terminated Diamond MOSFETs Using Ultrathin Glassy Ga2O3 Dielectric Formed by Low-Temperature Liquid Metal Printing Method

“…The transconductance, g m , starts to increase from V th to more negative gate biases, and reached a peak value of 0.16 mS/mm at V gs = 0.26 V. The on–off ratio is determined to be approximately 10 3 , as show in Figure S2. This considerably lower on–off ratio compared to that reported in other works ,,,,, is again caused by the leakage current, which can be optimized by the same strategy discussed above. The subthreshold swing is calculated as approximate 209 mV/dec (Figure S2.…”

“…In addition, the high temperature required for ALD, typically several hundred degrees Celsius, plus the presence of oxidizing precursors, could result in partial stripping of the hydrogen termination and degradation of device performance. An alternative “dry-transfer” technique through direct transfer of two-dimensional van der Waals dielectric flakes, such as h -BN, to the diamond surface at a relatively low temperature (∼100 °C) has been recently demonstrated which preserves the hydrogen termination and at the same time enhances the carrier mobility . However, the inherent nonscalability of mechanical exfoliation, which produces irregular-shaped flakes with inconsistent thickness and size, makes dry transfer of h- BN not viable for practical diamond device application.…”

Efficient n-Type Surface Doping in Diamond

“…Recently, researchers used the monocrystalline hexagonal BN at the interface with the diamond heterojunction and found that the quality of the two-dimensional hole gas channel improved (a sheet hole carrier density of 5 × 10 12 cm −2 and a hole carrier mobility of 680 cm 2 V −1 s −1 ), because the number of surface-charged impurities effectively reduced. 32,33 The schematic energy-level diagrams before and after the deposition of DMC and CoCp 2 are presented in Figure 5. In the VASP calculation, the position of the band edge (CBM) for N-terminated diamond can be determined through the band structure calculation.…”

“…Consequently, if diamond with a lower impurity concentration and a smoother surface (lower carrier scattering probability) is chosen for the Hall measurement, a higher mobility may be obtained. Recently, researchers used the monocrystalline hexagonal BN at the interface with the diamond heterojunction and found that the quality of the two-dimensional hole gas channel improved (a sheet hole carrier density of 5 × 10 12 cm –2 and a hole carrier mobility of 680 cm 2 V –1 s –1 ), because the number of surface-charged impurities effectively reduced. , …”

Point Defect Stability and Dielectric Properties of Graphene-Like Monolayer Materials

“…Generally, 2D materials are mainly applied as gate dielectrics or channel materials in compact, fast, and energy-efficient devices; − because of that, they could substantially reduce the channel length and thickness, contributing to smaller processes and higher integration in device manufacture. − Recently, h-BN has been successfully applied as a gate dielectric in field-effect transistors (FETs), whose mobility stays the highest among FETs based on a diamond surface channel reported to date. − As bearing the same structure and similar features as h-BN, the GLMMs are naturally at the heart of the research for novel devices, especially regarding their dielectric properties. For electronic devices, the dielectric constant (ε) is a fundamental electrical property that determines the capacitance and charge screening.…”