Aluminum-induced crystallization of amorphous silicon–germanium thin films

Abstract

Aluminum-induced layer exchange (ALILE) was used to crystallize amorphous silicon–germanium (a-Si1−xGex) alloys. A bilayer structure of aluminum (Al) and a-Si1−xGex was deposited on quartz substrates and annealed below the eutectic temperature of the binary Al–Ge alloy (420°C). The annealing process results in an almost complete exchange of the two layers and leads to the crystallization of the initially amorphous Si1−xGex thin films. Elastic recoil detection and Raman spectroscopy were used for structural characterization. The polycrystalline Si1−xGex (poly-Si1−xGex) samples show good structural properties over the entire composition range. In particular, no significant phase segregation was observed. Thus, ALILE has a high potential for the fabrication of polycrystalline Si1−xGex layers.