Open AccessThe effect of back-barrier layer on the carrier distribution in the AlGaN/GaN double-heterostructure
Author(s) -
Jincheng Zhang,
Zheng Peng-Tian,
Dong Zuo-Dian,
Duan Huantao,
Jian Ni,
Jinfeng Zhang,
Yue Hao
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.58.3409
Subject(s) - materials science , heterojunction , band diagram , barrier layer , metalorganic vapour phase epitaxy , fermi gas , optoelectronics , sapphire , rectangular potential barrier , layer (electronics) , charge carrier density , electron , optics , nanotechnology , epitaxy , physics , laser , quantum mechanics , doping
The one-dimensional self-consistent simulation of the band diagram and carrier distribution of the AlGaN/GaN double hetero-structure is firstly carried out to research the effect of the thickness and Al content of the AlGaN back-barrier layer on the carrier distribution. Then the AlGaN/GaN double hetero-structure materials with different back-barrier layers were grown by low-pressure MOCVD method on c-plane sapphire substrate. The mercury probe CV measurement was carried out to verify the results of theoretical simulation. The results of theoretical simulation and experiment both indicate that with the increase of Al content and thickness of the AlGaN back-barrier layer, the two-dimensional electron Gas density becomes low in the main channel and high in the parasitic channel gradually.The increase of Al content and thickness of the AlGaN back-barrier layer effectively enhances the two-dimensional electron Gas confinement but simultaneity produces higher-density parasitic channel. So a compromise has to be made between the improvement of the two-dimensional electron Gas confinement and the restraint of the carrier density in parasitic channel in designing the double heterostructure.