Study and Development of Hexagonal Boron Nitride-based Electronics

Wide bandgap semiconductors have extensive applications in high-temperature highpower electronics. Thus far, GaN- and SiC-based optoelectronic and power devices have been commercially available: Such devices can operate in hostile environments where conventional Si- and GaAs-based electronics cannot function. The increasing requirements on applications of electronic and optoelectronic devices under more extreme conditions prompt further research on the development of innovative semiconductor materials and devices. Hexagonal boron nitride (hBN) has many characteristics superior to GaN and SiC, which makes it a very attractive material for fabricating high-power electronic devices being able to work under even harsher conditions. The direct bandgap of hBN also enables fabrication of high-efficiency optoelectronic devices emitting deep-UV light. Moreover, hBN films can be grown on a variety of substrates by different deposition methods, which makes the applications of hBN films more practicable and more cost-effective. However, the study of the electronic and optoelectronic applications of hBN is still in its infancy and lots of open questions remain.This project will focus on the fabrication of high-temperature high-power hBN-based electronics, such as field effect transistors (FETs), and p-n diodes, based on the synthesis of high-quality hBN films by chemical vapor deposition (CVD) and doping by ion implantation. The doping efficiency and activation energy of selected dopants will be evaluated, and the effects of deposition, ion implantation and annealing parameters on the electrical and transport properties of hBN films will be systematically studied. The outcome of the project is expected to provide enhanced fundamental understanding and new process guidelines for the fabrication of hBN-based devices for practical applications. This proposal is based on the extensive experience of the investigators in the areas of thin film synthesis and doping techniques of relevant wide bandgap materials such as diamond, cubic BN and AlN in particular, and as well of the characterization and studies of electronic and transport properties of materials in general. The preliminary results from our research have already demonstrated the feasibility of preparing p- and n-type hBN films by ion implantation. Combination of the multi-disciplinary and complementary expertise among the participating members of this research team further guarantees the successful outcome and significant impact of the project.