Laser-induced aluminium-assisted crystallization of Ge-rich Si_xGe_1-x epitaxy on Si

Single crystalline Ge-rich Si_xGe_1-x epitaxially grown on a Si substrate is attracting great attention for its potential in optical and electronic device applications. One method of achieving Si_xGe_1-x epitaxy is by aluminium-assisted crystallization although the challenge of controlling the Si content in the Si_xGe_1-x is limited by the furnace annealing process. Herein, we report the use of a diode laser to induce aluminium-assisted crystallization of Si_xGe_1-x on Si with minimal Si content in the Si_xGe_1-x layer. By replacing furnace heat treatment with laser treatment, the reaction time is shortened from minutes to milliseconds which can limit the amount of Si incorporation into the Si_xGe_1-x films. X-ray diffraction, Raman spectroscopy, transmission electron microscopy and X-ray spectroscopy analyses are conducted on the fabricated films revealing the achievement of Ge-rich Si_xGe_1-x on Si through laser-induced aluminium-assisted crystallization. The higher laser dose may slightly increase the Si content and improve the crystallinity of the Si_xGe_1-x films.