Daphne Agapiou
Pronouns: she/her
Research Mentor(s): Zhe Jian
Co-Presenter:
Research Mentor School/College/Department: Electrical Engineering and Computer Science Department / Engineering
Presentation Date: April 20
Presentation Type: Poster
Session: Session 4 – 2:40pm – 3:30 pm
Room: League Ballroom
Authors: Daphne Agapiou, Zhe (Ashley) Jian
Presenter: 106
Abstract
Today, demand for higher power devices is increasing for transportation and industrial needs, such as in electric vehicles and high-speed trains. Common materials used in these power electronics include silicon, gallium nitride(GaN), and gallium oxide(Ga2O3) . However, there are some limitations to these materials. Traditional silicon-based power electronics systems are heavy, bulky, and relatively inefficient. Ga2O3 is a promising candidate for high power semiconductor devices but it poses challenges as it has a low electron mobility, meaning low current will inhibit higher frequency, and low thermal conductivity, making it easier for devices to become warmer and break [1,2]. On the other hand, GaN has a high electron mobility, allowing for high frequency, and a high thermal conductivity to avoid overheating of devices [3]. This research focuses on the nano-scale integration of GaN and Ga2O3, with the goal in mind to create high-power and high-frequency devices. To proceed with the bonding of GaN and Ga2O3, the bonding interface properties are investigated through atomic force microscopy (AFM) and scanning electron microscopy (SEM). AFM is utilized to determine the surface roughness of the sample; if higher than 0.5nm, the bonding between GaN and Ga2O3 should not occur. After, SEM is performed to provide a larger scale view of the surface morphology of the sample. These steps determine if the surface is flat, smooth, and clean, to improve the properties of the bonding interface between GaN and Ga2O3. High angle annular dark field scanning transmission electron microscopy (HAADF-STEM) is utilized to characterize the crystal quality of bonded ß-Ga2O3/N-polar GaN interface. The integration of Ga2O3 on GaN substrate achieved in this work is a promising approach to combine the material merits of both GaN and Ga2O3 targeting the fabrication of novel GaN/ß-Ga2O3 high-frequency and high-power electronics as well as optoelectronic devices. References: [1] Z. Guo et al., Appl. Phys. Lett., vol. 106, no. 11, p. 111909, Mar. 2015. [2] Z. Feng et al., Appl. Phys. Lett., vol. 114, no. 25, p. 250601, Jun. 2019. [3] H. Shibata et al., Mater. Trans., vol. 48, no. 10, pp. 2782–2786, Oct. 2007.
Engineering
