Epitaxial growth of SiGe on Si substrate by printing and firing of Al–Ge mixed paste

We report on a simple liquid-phase epitaxy (LPE) of SiGe on Si (100) substrate based on printing and firing. LPE was performed using an Al–Ge mixed paste screen-printed on a Si (100) substrate followed by annealing above the Al–Ge eutectic temperature in air or in an Ar atmosphere. In the case of annealing in air at 800 °C, SiGe was formed between the mixed paste and the surface of the Si substrate. However, a wave-like oxide film was confirmed at the SiGe/Si interface, which hindered the growth of SiGe. On the other hand, annealing in the Ar atmosphere at 800 °C led to the successful formation of a more continuous, thicker SiGe film by suppressing the oxidation of Al. It can be concluded that LPE growth using printing and firing of Al–Ge mixed paste is a suitable method to grow SiGe with a low-cost and simple high-speed process.