Thermally induced surface faceting on heteroepitaxial layers

Zhang，Yiwen1; Zhou，Chuan1; Zhu，Ying1,2; Xia，Guangrui (maggie)2; Li，Lei1; Wen，Rui Tao1

2023-02-21

10.1063/5.0133765

JOURNAL OF APPLIED PHYSICS   Impact Factor & Quartile

0021-8979

1089-7550

Heteroepitaxial semiconductors such as Ge-on-Si are widely used in current opto-electronic and electronic applications, and one of the most important challenges for epitaxial Ge-on-Si is threading dislocations (TDs) in Ge layers caused by lattice mismatch between Ge and Si. Here, apart from traditional wet chemical etching, we report a convenient approach to evaluate the threading dislocation densities in heteroepitaxial layers through vacuum thermal annealing. More importantly, the controversial origin of thermal annealing induced pits on a Ge surface was addressed in this work. By combining both experiments and density functional theory (DFT) calculations, we find that the {111} facets defined thermal pits on Ge (001) surfaces are mainly caused by threading dislocation activation. Ge adatoms at the TD segments sublimate preferentially than the ones on dislocation-free Ge (001) surface regions, and its further evolution is determined by surface energies of {111} facets, leading to a construction of inverted pyramid-shaped thermal pits.

SCI

English

First ; Corresponding

National Natural Science Foundation of Guangdong Province[2022A1515010216] ; National Natural Science Foundation of China[52172294] ; "Shenzhen Science and Technology Innovation Commission"["JCYJ20210324105402007","20220815095607001"] ; Guangdong Provincial Innovation and Entrepreneurship Project[2017ZT07C071] ; Guangdong Provincial Key Laboratory Program from the Department of Science and Technology of Guangdong Province[2021B1212040001]

Physics

Physics, Applied

WOS:000958356700012

AIP Publishing

PHYSICS

2-s2.0-85148770796

Scopus

1.Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,518055,China
2.Department of Materials Engineering,The University of British Columbia (UBC),Vancouver,V6T 1Z4,Canada

Zhang，Yiwen,Zhou，Chuan,Zhu，Ying,et al. Thermally induced surface faceting on heteroepitaxial layers[J]. JOURNAL OF APPLIED PHYSICS,2023,133(7).

Zhang，Yiwen,Zhou，Chuan,Zhu，Ying,Xia，Guangrui ,Li，Lei,&Wen，Rui Tao.(2023).Thermally induced surface faceting on heteroepitaxial layers.JOURNAL OF APPLIED PHYSICS,133(7).

Zhang，Yiwen,et al."Thermally induced surface faceting on heteroepitaxial layers".JOURNAL OF APPLIED PHYSICS 133.7(2023).