Significant reduction of crack propagation in the strained SiGe/Ge(111) induced by the local growth on the depth-controlled area patterning

Abstract

We propose a method for obtaining crack-free fully-strained SiGe layers on Ge(111). To achieve the crack-free strained SiGe layers, we introduce patterned area with a sufficient depth (step height) of more than 1 µm on Ge(111) substrates. Because of the complete suppression of the crack propagation from the SiGe layer grown on the outside of the patterned area on Ge(111), we achieve crack-free fully strained SiGe layers on the inside of the patterned area. This approach will drastically expand applicability of the strained SiGe to the fields of Si photonics and spintronics.

Local strain distribution analysis in strained SiGe spintronics devices

“…Recent studies have shown that defects such as ridges and cracks are prevented from propagating by etching at sufficient depth to form a mesa pattern and growing a SiGe layer. 31,32) By applying such a technique, it is expected that high-performance devices can be fabricated efficiently.…”