Influences of ALD Al2O3 on the surface band-bending of c-plane, Ga-face GaN

The recently demonstrated approach of grafting n-type GaN with p-type Si or GaAs, by employing ultrathin Al2O3 at the interface, has shown the feasibility to overcome the poor p-type doping challenge of GaN. However, the surface band-bending of GaN that could be influenced by the Al2O3 has been unknown. In this work, the band-bending of c-plane, Ga-face GaN with ultrathin Al2O3 deposition at the surface of GaN was studied using X-ray photoelectron spectroscopy (XPS). The study shows that the Al2O3 can help suppress the upward band-bending of the c-plane, Ga-face GaN with a monotonic reduction trend from 0.48 eV down to 0.12 eV as the number of Al2O3 deposition cycles increases from 0 to 20. The study further shows that the band-bending can be mostly recovered after removing the Al2O3 layer, concurring that the introduction of ultrathin Al2O3 is the main reason for the surface band-bending modulation.

Gong, J., Lu, K., Kim, J., Ng, T. K., Kim, D., Zhou, J., … Ma, Z. (2021). Influences of ALD Al2O3 on the surface band-bending of c-plane, Ga-face GaN. Japanese Journal of Applied Physics. doi:10.35848/1347-4065/ac3d45

The work was supported by Air Force Office of Scientific Research under grant FA9550-21-1-0081.

IOP Publishing

Japanese Journal of Applied Physics


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