NIMS Unveils Revolutionary N-Channel Diamond Transistor for Extreme Conditions

NIMS Unveils Revolutionary N-Channel Diamond Transistor for Extreme Conditions
by Riko Seibo
Tokyo, Japan (SPX) Mar 22, 2024

Researchers at the National Institute for Materials Science (NIMS) have successfully developed the world's first n-channel diamond metal-oxide-semiconductor field-effect transistor (MOSFET), marking a major advancement in semiconductor technology. This innovation opens the door to creating diamond-based complementary metal-oxide-semiconductor (CMOS) integrated circuits, particularly beneficial for devices operating under severe conditions.

The exceptional properties of semiconductor diamond, including its ultra-wide bandgap energy, high carrier mobilities, and superior thermal conductivity, make it an ideal candidate for applications in extreme environments, such as high temperatures and radiation levels found near nuclear reactors. Diamond electronics promise to alleviate the thermal management challenges of conventional semiconductors, offering higher energy efficiency, endurance for higher breakdown voltages, and resilience in harsh settings. The development of diamond growth technologies has spurred the need for diamond CMOS devices for monolithic integration in power electronics, spintronics, and microelectromechanical systems (MEMS) sensors that operate under demanding conditions.

The NIMS team has pioneered a method for cultivating high-quality monocrystalline n-type diamond semiconductors, embedding them with a low concentration of phosphorus to achieve smooth, flat terraces at the atomic level. This technique led to the successful fabrication of an n-channel diamond MOSFET, a significant achievement given the previous absence of such devices. The novel MOSFET features an n-channel diamond semiconductor layer placed over another highly phosphorus-doped diamond layer, which notably reduces source and drain contact resistance. Testing confirmed the MOSFET's functionality as an n-channel transistor and demonstrated its exceptional high-temperature performance, evidenced by a field-effect mobility of about 150 cm2/V?sec at 300 C.

This development is poised to significantly impact the production of CMOS integrated circuits for energy-efficient power electronics, spintronic devices, and MEMS sensors capable of withstanding extreme conditions.

Research Report:High-temperature and high-electron mobility metal-oxide-semiconductor field-effect transistors based on n-type diamond