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The influence of Al composition in AlGaN back barrier layer on leakage current and dynamic R ON characteristics of AlGaN/GaN HEMTs
Author(s) -
He Liang,
Li Liuan,
Zheng Yue,
Yang Fan,
Shen Zhen,
Chen Zijun,
Wang Wenjing,
Zhang Jialin,
Zhang Xiaorong,
He Lei,
Wu Zhisheng,
Zhang Baijun,
Liu Yang
Publication year - 2017
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.201600824
Subject(s) - materials science , optoelectronics , doping , leakage (economics) , layer (electronics) , substrate (aquarium) , barrier layer , composite material , economics , macroeconomics , oceanography , geology
In the study, thin Al x Ga 1− x N back barrier layer ( BBL ) with different Al composition ( x ) was employed in AlGaN/GaN HEMTs with GaN/AlN SLs schemes on Si substrate. The AlGaN BBL with low Al content ( x < 0.15) has no significant effect on the crystalline quality, while a higher Al content will induce more dislocations and cause surface defects. The DC I–V characteristics show that AlGaN BBL ( x = 0.1 and 0.15) is beneficial for obtaining high I on / I off ratio of 10 8 and improving the off‐state behaviors with lower leakage current and higher breakdown voltage. The dynamic R ON measurements were performed by applying the drain pre‐bias switching and different quiescent bias pulse tests. It is shown that the AlGaN BBL can effectively suppress the R ON, dynamic degradation, due to that the channel electrons trapped in the C‐doping buffer were reduced by mitigating the electrons spill‐over effect under the strong off‐state bias. However, the device with higher Al‐content AlGaN BBL exhibits a rising R ON, dynamic caused by the surface defects related traps. Overall, the devices with 0.1 and 0.15 Al‐content AlGaN BBL have an optimal performance.