Open AccessCritical thickness of strained Si1-xGex on Ge(111) and Ge-on-Si(111)
Author(s) -
Md. Mahfuz Alam,
Youya Wagatsuma,
Kazuya Okada,
Yusuke Hoshi,
Michihiro Yamada,
Kohei Hamaya,
Kentarou Sawano
Publication year - 2019
Publication title -
applied physics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.911
H-Index - 94
eISSN - 1882-0786
pISSN - 1882-0778
DOI - 10.7567/1882-0786/ab2db8
Subject(s) - nucleation , materials science , substrate (aquarium) , germanium , dislocation , crystallography , spintronics , ridge , condensed matter physics , silicon , optoelectronics , chemistry , thermodynamics , physics , composite material , paleontology , oceanography , ferromagnetism , geology , biology
Critical thicknesses ( t c ) of Ge-rich strained Si 1-x Ge x layers grown on various Ge substrates are precisely determined experimentally, and t c is revealed to strongly depend on the substrate conditions. We find that t c of Si 1-x Ge x on Ge-on-Si(111) is much lower than that on the Ge(111) substrate for x > 0.75 while, for x < 0.75, t c becomes equivalent between both substrates, origins of which can be discussed in terms of dislocation nucleation and surface ridge formation. This study provides critical design parameters for strained SiGe(111) based devices, such as high-mobility channels and spintronic devices on a Si platform.