Single‐crystal Ge films on SiO2‐coated Si wafers by laterally seeded heteroepitaxy

摘要

Germanium film crystallization with W encapsulation has been performed by using rf zone‐heating slider system. With the laterally seeded heteroepitaxy technique, (100) single‐crystal Ge is obtained on SiO2 islands as large as 280×510 μm on Si(100) substrates. The Ge surface morphology represents growth‐velocity anisotropy, indicating a {111}‐faceted liquid‐solid interface during crystallization. It has been shown that a mixture of Ge crystal and polycrystalline Si2W exists at the peripheral region of the SiO2 island and at the Si opening. Si2W formation is explained by diffusion of substrate Si atoms in Ge followed by reaction with the encapsulant W. The crystalline quality of Ge near the seed is poor because of the Ge lattice deformation due to Si2W. Lateral epitaxy, however, is successfully performed to provide a good‐quality Ge single‐crystal film on the SiO2 island.