Abstract
The material properties of GeSn structures fabricated on Silicon substrate by Rapid-Melt-Growth (RMG) method was investigated. We fabricated several GeSn strips, and because of the lower melting point of Sn, it would be pushed to the end of the strip and then solidified during the liquid phase epitaxial process. Therefore, there would be a varying concentration of Sn distributed inside the GeSn strip. We measured the Micro-Photoluminescence (Micro-PL) spectra at different locations from seed window of the strip and analyzed the concentration of Sn. In addition, the above results were compared with the results obtained from Micro-Raman spectroscopy. In order to have large-area, high-concentration of GeSn alloy on Si substrate by RMG method, we fabricated a large-area GeSn rod array and analyzed the crystal quality and element concentration in each rod by SEM and TEM. Besides, we studied the RMG process on the GeSn alloy with an amorphous silicon (a-Si) layer cap and evaluated the influence on the Sn distribution.