Wide bandgap electronics made from Gallium Nitride (GaN) and Gallium Oxide (Ga2O3) are currently under development due to their potential to create some of the most advanced RF, power electronic, and optoelectronic devices in the world. However, these devices can operate at high power densities and electric fields which makes their thermal control and device reliability a challenge. The vast majority of GaN electronics are grown heteroepitaxially onto non-native substrates which introduces defects into devices and inherently requires several interfaces that can impede heat dissipation from the devices. Thus, it is the control of the material during the growth phase that allows engineers to impact their electrothermal behavior, leading to advanced high-power density devices that are expected in the future. For Ga2O3, homoepitaxy is possible, but the thermal properties of gallium oxide are low and present additional thermal challenges. Considering that heat fluxes from these devices can greatly exceed 1 kW/cm2, advanced thermal control solutions integrated within the device architecture and accurate thermal metrology to verify the reduction in device junction temperature are needed to improve the thermal performance and reliability of GaN electronics.
In this talk we will discuss advancements in thermal characterization techniques that have allowed new insights into GaN and Ga2O3 materials and devices, with a specific focus on the role of device architecture and processing on their thermal performance. This will include high speed transient thermoreflectance and gate resistance thermometry methods developed in our group. We will discuss in some detail the role of interfaces on the thermal boundary resistance and the fundamental challenges that must be addressed to lead to the tailoring of this thermal resistance in the devices. We will then discuss advancements in RF and power electronic devices including those made on bulk GaN and Ga2O3 substrates and the thermal challenges and opportunities that exist for recent bulk GaN technology.
Host: Damena Agonafer
Faculty, students, and the general public are invited.
Hosted by: Damena Agonafer