Cubic Boron Nitride Diodes and Transistors

In support of missions to the Moon and Mars, NASA needs high-voltage, high-current power electronic components that tolerate heavy-ion-radiation-induced damage without catastrophic failure. Diodes with 1200V 40A capability and transistors that operate at 600V 40A are desired for use in systems. Even after ~25 years of development, space-qualified GaN components are limited to 300V operation. In 2014, Hirama and colleagues at NTT demonstrated the MBE growth of cubic BN [1-2] on (100) diamond substrates. In 2022, Storm [3] at NRL reproduced the Japanese MBE growth result. In 2022, OSEMI custom-built a c-BN MBE system in the configuration described by Hirama and utilized it to demonstrate the initial growth of c-BN epitaxial layers in 2023. In this NASA Phase I effort, OSEMI proposes to extend its work on c-BN epitaxy to include the doped layers required to make diodes and transistors in c-BN. Initially, the growth and processing of p-n diodes will be investigated on 2-inch diameter substrates. We will also attempt the growth and fabrication of a lateral c-BN MESFET followed by a c-BN n-p-n bipolar transistor with further refinements of all three devices, including radiation tolerance life testing in a Phase II program. The goal in a Phase II effort will be to scale the growth and fabrication technology to 100mm diameter wafers, complete life testing, and achieve a new generation of c-BN Power Electronic Components and RF devices to provide a foundation for a next generation of chemically inert radiation tolerant power subsystems and communication modules useful in extreme environment that include missions to the Moon, Mars and on satellites for NASA. In this program, OSEMI proposes to replace GaN electronic components with c-BN components that are anticipated to perform at higher voltage and current than GaN in extreme environments.