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Investigation of O 3 ‐Al 2 O 3 /H 2 O‐Al 2 O 3 dielectric bilayer deposited by atomic‐layer deposition for GaN MOS capacitors
Author(s) -
Shen Zhen,
He Liang,
Zhou Guilin,
Yao Yao,
Yang Fan,
Ni Yiqiang,
Zheng Yue,
Zhou Deqiu,
Ao Jinping,
Zhang Baijun,
Liu Yang
Publication year - 2016
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201532785
Subject(s) - materials science , atomic layer deposition , analytical chemistry (journal) , oxidizing agent , dielectric , chemical vapor deposition , bilayer , layer (electronics) , optoelectronics , chemistry , nanotechnology , biochemistry , organic chemistry , chromatography , membrane
In this work, H 2 O‐Al 2 O 3 /O 3 ‐Al 2 O 3 insulating bilayers were grown on GaN by atomic‐layer deposition (ALD) technique using H 2 O vapor and O 3 as oxidants. The electrical and material properties show that the H 2 O‐Al 2 O 3 /O 3 ‐Al 2 O 3 stack structure appeared to be an appropriate dielectric for GaN MOS devices that had low leakage current densities, high breakdown voltages, and good capacitance–voltage ( C–V ) curves. The H 2 O‐Al 2 O 3 interlayer between the O 3 ‐Al 2 O 3 and GaN efficiently prevented the GaN surface from oxidizing by ozone oxidant by its strong oxidizing power. By taking photo‐assisted C–V measurements, it was found that the deep interface state densities at the Al 2 O 3 /GaN interface reduced, while increasing the thicknesses of the H 2 O‐Al 2 O 3 interlayer restricted the “V th shift” phenomenon and improved the stability and reliability of the GaN MOS devices.