Journal of Crystal Growth, Vol.416, 34-40, 2015
Single crystalline SiGe layers on Si by solid phase epitaxy
We demonstrate a straightforward way to obtain single crystalline SiGe layers on silicon substrates. Amorphous SiGe layers, deposited by plasma enhanced chemical vapour deposition on Si, are transformed into single crystalline and smooth layers by solid phase epitaxy during annealing in a N-2 atmosphere. The SiGe layers relax during the crystallization anneal and become slightly tensile strained during cooldown due to the thermal mismatch. The SiGe layers show excellent structural quality for compositions ranging horn Ge- to Si-rich. The Ge content can be accurately estimated from the SiH4 to GeH4 flow ratio. Furthermore, the crystallization temperature decreases linearly with increasing Ge content from 725 degrees C for a-Si to 475 degrees C for a-Ge. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:Characterization;Crystal structure;Plasma enhanced chemical vapour deposition;Solid phase epitaxy