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Increase in breakdown voltage of AlGaN/GaN HEMTs with a high‐ k dielectric layer
Author(s) -
Hanawa Hideyuki,
Horio Kazushige
Publication year - 2014
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.201300403
Subject(s) - passivation , breakdown voltage , materials science , optoelectronics , insulator (electricity) , voltage drop , transistor , semiconductor , gallium nitride , electric field , voltage , drop (telecommunication) , layer (electronics) , electrical engineering , composite material , physics , quantum mechanics , engineering
A two‐dimensional analysis of breakdown characteristics in AlGaN/GaN high‐electron‐mobility transistors (HEMTs) is performed by considering a deep donor and a deep acceptor in a buffer layer. The dependence of an off‐state breakdown voltage on the relative permittivity of the passivation layer ϵ r is studied. It is shown that as ϵ r increases, the off‐state breakdown voltage increases. This is because the electric field at the drain edge of the gate is weakened as ϵ r increases. This occurs because in the insulator the applied voltage tends to drop uniformly in general, and hence when the insulator is attached to the semiconductor, the voltage drop along the semiconductor becomes smoother at the drain edge of the gate if ϵ r of the insulator is higher and the effect of the insulator becomes more significant. It is concluded that AlGaN/GaN HEMTs with a high‐ k passivation layer should have high breakdown voltages.