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
Affiliations
Shuoyang Qiu
Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Jiarui Gong
Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Jie Zhou
Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Tien Khee Ng
Department of Computer, Electrical and Mathematical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
Ranveer Singh
Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Moheb Sheikhi
Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
Boon S. Ooi
Department of Computer, Electrical and Mathematical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
Zhenqiang Ma
Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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.
