In situ istraživanje termičkog raspada epitaksijalnih slojeva GeSn legure transmisijskom elektronskom mikroskopijom

The \( Ge_{1-x}Sn_{x}\) alloy with x>0.01 is thermodynamically metastable and Sn tends to diffuse, segregate or precipitate as β-Sn in a droplet-like structure at temperature above ≈230°C. In situ heating experiments via transmission electron microscopy (TEM) allows us to observe and study the decomposition process of \( Ge_{1-x}Sn_{x}\). The main requirement for TEM investigation is an electron transparent specimen. Hence, specimen preparation is a key step towards TEM experiments. The sample preparation procedure has been developed using a combination of preparation techniques. The MBE synthesized \( Ge_{1-x}Sn_{x}\) and reference material Si (with Ge quantum dots) have been prepared with wedge polishing technique. Further, focused ion beam (FIB) has been used to prepare a heating chip for the in situ TEM heating experiment. Various microscopy methods have been used to optimize and validate the developed sample preparation procedure.