Silicon has provided enormous benefits to the power electronics industry. But performance of silicon-based power electronics is nearing maximum capacity.
Enter wide bandgap (WBG) semiconductors. Seen as significantly more energy-efficient, they have emerged as leading contenders in developing field-effect transistors (FETs) for next-generation power electronics. Such FET technology would benefit everything from power-grid distribution of renewable-energy sources to car and train engines.
Diamond is largely recognized as the most ideal material in WBG development, owing to its superior physical properties, which allow devices to operate at much higher temperatures, voltages and frequencies, with reduced semiconductor losses.
A main challenge, however, in realizing the full potential of diamond in an important type of FET—namely, metal-oxide-semiconductor field-effect transistors (MOSFETs)—is the ability to increase the hole channel carrier mobility. This mobility, related to the ease with which current flows, is essential for the on-state current of MOSFETs.
Researchers from France, the United Kingdom and Japan incorporate a new approach to solve this problem by using the deep-depletion regime of bulk-boron-doped diamond MOSFETs. The new proof of concept enables the production of simple diamond MOSFET structures from single boron-doped epilayer stacks. This new method, specific to WBG semiconductors, increases the mobility by an order of magnitude. The results are published this week in Applied Physics Letters.