Nanomembrane β-Ga(2)O(3) High-Voltage Field Effect Transistors
Nanomembrane high-voltage FETs with β -Ga2 O3 channels were fabricated and characterized for the first time. The large bandgap leads to a high on/off ratio. A flat interface between β -Ga2 O3 and SiO2 leads to a steep slope of ~ 150 mV/dec. The high breakdown field of β -Ga2 O3 allow significantly higher voltages to be applied to the drain, while still switching by orders of magnitude. Since β -Ga2 O3 has been found to have a rather poor thermal conductivity, nanoscale membranes might offer opportunities for efficient heat removal. Nanoscale membranes can also be self-depleted even when doped lightly, and thus form semi-insulating layers, which may make it possible to make FETs without controlled epitaxy. A primary challenge is the formation of ohmic contacts.