Hydrogen-Terminated Diamond MOS Capacitors, MOSFETs, and MOSFET Logic Circuits

Wide-bandgap semiconductor diamond has been studied to develop high-power, high-frequency, and high-temperature electronic devices. However, their development has been limited by the low free carrier density that occurs in diamond at room temperature because of the high activation energies of p-typeP-type boron and n-typeN-type phosphorus dopants. Fortunately, hydrogen-terminated diamond (H-diamond) can accumulate two-dimensional hole gases on its surface with a high free carrier density. In this chapter, we review our recent progress in the fabrication of H-diamond metal–oxide–semiconductor (MOS) capacitors, MOS field-effect transistorsMOS field-effect transistors (MOSFETs), and MOSFET logic circuits. Specifically, the leakage current densities for different oxide insulators on H-diamond and the capacitance–voltage properties for the Al2O3/H-diamond MOS capacitors are discussed. Planar-type, T-typeT-type, and triple-gate fin-type H-diamond MOSFETs are reviewed, and the fabrication and performance of depletion- and enhancement-modeEnhancement-mode H-diamond MOSFETs and logic circuits are summarized.