Post growth thermal treatments of Si1-x-yGexSny alloys

Si1-x-yGexSny alloys are promising materials for future applications in opto- and nanoelectronics. These alloys enable effective band gap engineering, a broad adjustability of the lattice parameter, exhibit much higher carrier mobility than pure Si and are compatible with CMOS technology. Unfortunately, the equilibrium solid solubility of Sn in Si1-xGex is less than 1% and pseudomorphic growth of Si1-xyGexSny on Ge or Si causes in-plane compressive strain in the grown layer, which degrades the superior properties of the alloys. Therefore, the post-growth strain engineering using ultrafast non-equilibrium thermal treatments like flash lamp annealing (FLA) or pulsed laser annealing (PLA) to improve the layer quality is needed. In this contribution, we discuss the influence of millisecond FLA and nanosecond PLA on Si1-x-yGexSny alloys and present an efficient way to improve the layer quality of thin film Si1-x-yGexSny on insulator by PLA. Different Si1-xyGexSny alloys are directly grown on commercial silicon-on-insulator (SOI) wafers and treated by FLA or PLA. The material is analysed by micro-Raman spectroscopy, Rutherford backscattering spectrometry (RBS) and X-ray diffraction (XRD) before and after the thermal treatments. It is shown that after annealing, the material is single-crystalline with much better crystallinity than the as-grown layer.