Cooling Rate Dependent Lattice Rotation in Ge on Insulators Formed by Rapid Melt Growth

Abstract

rotated rapidly in the forward section of the Ge strip but slowly in the backward section. The Ge lattice twist monotonically increased with increased soaking temperature. The increase of soaking temperature could induce two factors in the recrystallization process of Ge, which might be related to the twist. First, Si‐Ge interdiffusion was enhanced with increased soaking temperature. The different atomic radii of Si (0.117 nm) and Ge (0.122 nm) may induce strain energy along the strips, which may be related to the lattice rotation in Ge strips. 11 Second, the cooling rate in the recrystallization of Ge decreased with lowered soaking temperature in the RTA process, was determined by the thermal radiation cooling process and requires further investigation. To investigate the relationship between Si‐Ge interdiffusion along the Ge strips and the lattice twist, 150 nm-thick, 2 × 200 μm 2 Ge strips annealed at 967 ◦ C were prepared. Figure 3a shows the typical lattice twist curve of the 200 μm-long Ge strip. The results indicated that a crystal orientation identical to the Si substrate was obtained near the seeding area, and the lattice orientation changed with increased growth length until the end of the strip. Micro-probe Raman spectroscopy measurements were also performed as a function of the distance from the seeding areas. The typical Raman