Interfacial band parameters of ultrathin ALD-ZrO2 on Ga-polar GaN through XPS measurements

Shuoyang Qiu, Jiarui Gong, Jie Zhou, Tien Khee Ng, Ranveer Singh, Moheb Sheikhi, Boon S. Ooi, Zhenqiang Ma

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Recent demonstrations of grafted p-n junctions combining n-type GaN with p-type semiconductors have shown great potential in achieving lattice-mismatch epitaxy-like heterostructures. Ultrathin dielectrics deposited by atomic layer deposition (ALD) serve both as a double-sided surface passivation layer and a quantum tunneling layer. On the other hand, with excellent thermal, mechanical, and electrical properties, ZrO2 serves as a high-k gate dielectric material in multiple applications, which is also of potential interest to applications in grafted GaN-based heterostructures. In this sense, understanding the interfacial band parameters of ultrathin ALD-ZrO2 is of great importance. In this work, the band-bending of Ga-polar GaN with ultrathin ALD-ZrO2 was studied by x-ray photoelectron spectroscopy (XPS). This study demonstrated that ZrO2 can effectively suppress upward band-bending from 0.88 to 0.48 eV at five deposition cycles. The bandgap values of ALD-ZrO2 at different thicknesses were also carefully studied.
Original languageEnglish (US)
JournalAIP Advances
Issue number5
StatePublished - May 5 2023

Bibliographical note

KAUST Repository Item: Exported on 2023-05-08
Acknowledged KAUST grant number(s): BAS/1/1614-01-01, REP/1/5313-01-01
Acknowledgements: S. Qiu was supported by the China Scholarship Council. J. Gong, J. Zhou, R. Singh, M. Sheikhi, and Z. Ma were supported by the Air Force Office of Scientific Research (AFOSR), under Grant No. FA9550-21-1-0081. B.S.O. and T.K.N. gratefully acknowledge the KAUST funding: BAS/1/1614-01-01 and REP/1/5313-01-01.

ASJC Scopus subject areas

  • General Physics and Astronomy


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