Open AccessSuspended-ultrathin Si membrane on SOI: a novel structure to reduce thermal stress of GaN epilayer
Author(s) -
Yun Heub Song,
Kejia Wang,
Pengwei Du,
Zhiyuan Cheng
Publication year - 2020
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/768/2/022053
Subject(s) - silicon on insulator , materials science , epitaxy , optoelectronics , silicon , substrate (aquarium) , layer (electronics) , dislocation , thermal , stress (linguistics) , membrane , composite material , chemistry , linguistics , oceanography , physics , philosophy , biochemistry , meteorology , geology
A 30nm-thick suspended-ultrathin silicon membrane based on SOI (silicon-on-insulator) substrate for GAN epitaxial growth is fabricated and analysed. We demonstrate that thermal stress of GaN in the effective area on this novel substrate can be reduced 44% more than that in normal SOI substrate, which can reduce the dislocation and crack density in GaN. The absence of BOX (buried oxide) layer are confirmed as main factors to result in reduction of thermal stress in GaN layer. This work provides a promising approach to obtain high-quality GaN by utilizing mechanical structure.