Open AccessInfluence of penetrating V-pits on leakage current of GaN based p-i-n UV detector
Author(s) -
S Zhang,
Zhao Dg,
Liu Zs,
Jiang Zhu,
Zhang Sm,
Wang Yt,
Duan Lh,
Liu Wb,
Ding-Sheng Jiang,
Hang Yang
Publication year - 2009
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.58.7952
Subject(s) - ohmic contact , materials science , schottky barrier , leakage (economics) , optoelectronics , schottky diode , contact resistance , dislocation , metal , gallium nitride , current density , layer (electronics) , composite material , metallurgy , physics , diode , quantum mechanics , economics , macroeconomics
The leakage mechanism of GaN-based p-i-n p-AlGaN/i-GaN/n-GaN UV detector has been investigated. With the same dislocation density, devices made from material with higher density of V-pits on surface produce larger leakage current. SEM images show that some V-pits penetrate into i-GaN layer, sometimes even the n-GaN layer. If p-ohmic contact metal Ni/Au deposits in the V-pits, Schottky contact would be formed at the interface of metal and i-GaN, or form ohmic contact at the interface of metal and n-GaN. The existence of parallel Schottky junction and ohmic contact resistance enhances the leakage current greatly.