Wafer scale epitaxial germanium on silicon (0 0 1) using pulsed laser annealing

Pulsed Nd:YAG (1064 nm) laser was used to crystallize amorphous germanium thin-films on silicon (0 0 1) wafer to get epitaxial Ge. Film thickness and laser fluence played a crucial role. Thicker films (≥300 nm) are polycrystalline while thinner films are epitaxial. Rocking curve measurements show improvement in crystallinity with increase in laser fluence. The full 2-in. laser crystallized wafer has omega scan of 0.20° and implied threading dislocation density of 6 × 108 cm−2. Hence, a fast, cost-effective, and low thermal budget process is used to achieve epitaxial Ge on Si for large area applications.