© 2018 The Japan Society of Applied Physics. A novel fabrication process based on direct bonding technologies is proposed and demonstrated to achieve polarity inversion in AlN. High-angle annular dark-field scanning transmission electron microscopy observation clearly showed an atomically flat bonding interface and an abrupt transition from Al polarity (+c) to N polarity (%c) through a single monolayer. This ideal polarity inversion of III-nitride materials is expected to provide new insight into heteropolar device applications.
Hayashi, Y., Katayama, R., Akiyama, T., Ito, T., & Miyake, H. (2018). Polarity inversion of aluminum nitride by direct wafer bonding. Applied Physics Express, 11(3). https://doi.org/10.7567/APEX.11.031003