EAGER: MOCVD Growth of beta-(Al,In,Ga)2O3 for Transistor Applications

The objective of this proposal is to study the MOCVD growth of β-Ga2O3 and related compounds such as β-(AlxGa1-x)2O3, β-(InxGa1-x)2O3, and β-(AlxInyGa1-x-y)2O3. This group has extensive experience in the growth of III-Nitrides—a similar wide bandgap material system—and has recently shown promising results by applying that experience to the growth of Ga2O3. We are proposing to undertake a 2 year comprehensive study of the material growth. In addition to this fundamental study we will also apply the material improvements to the development of transistors based on this material system. Intellectual merit: The core elements of this project are: (1) development of a fundamental understanding of the MOCVD growth of β-(Al,In,Gay)2O3; (2) Demonstrating effective doping of this wide bandgap material; (3) Demonstration of the ability to realize high quality hetero-interfaces; (4) Using the doping and hetero-interface enginenering to realize high mobility layers; and, (5) using all of that to demonstrate high performance transistors. The PI’s background is extremely well matched to the proposed research, and all the required resources and expertise are available. Broader impacts: Ga2O¬3 based devices are anticipated to yield a further 10x improvement over the already impressive performance of III-nitride-based devices, which have already shown the potential for a 10x improvement over commercial SiC based devices. The development of Ga2O3 for transistor applications will allow an unprecedented level of performance in applications that require high total continuous-wave (CW) power and efficiency as well as excellent linearity and performance at backed-off power levels. However, before these results can be achieved, a fundamental study of (Al,In,Ga)2O3 materials is necessary. The proposed research makes an excellent case study for how to develop new semiconductor materials from theory to growth. Theory, technology, and experiment all play a role in developing a new material and these fundamental aspects will be incorporated into the Solid State Engineering curriculum at Northwestern University as real-world examples. Graduate students and post-docs funded through this work will be encouraged to present this work to course attendees and at conferences. To increase the effectiveness and scope of the program, the involvement of undergraduates and high-school students (through mentorship) will be emphasized, by leveraging existing programs with a strong focus on under-represented minorities.