Ge diffusion and solid phase epitaxy growth to form Si _{1 - X}Ge_x/Si and Ge on insulator structure

We report growth of Si_{1 - x}Ge_x/Si and Ge on insulator by Ge diffusion and SPE (solid phase epitaxy). Different annealing conditions were carried out and evaluated by X-ray diffraction. Ge diffusion and SPE growth of Ge on Si are observed after annealing at 800 °C. EDX (electron dispersive X-ray) composition analysis shows that the top 100 Å Si _{1 - x}Ge_x layer is quite uniform with Ge content variation of less than 2%. TEM (transmission electron microscopy) picture shows no crystal orientation misalignment between the Si and the top Si_{1 - x}Ge _x layer. This simple and cost-effective process can be used to make Si_{1 - x}Ge_x /Si substrate for high-mobility metal oxide semiconductor field effect transistor application. In addition, Ge on insulator structure was achieved by SPE lateral growth on pre-patterned SiO₂.