Seeded Growth of Si Over SiO2 Substrates by CW Laser Irradiation

Seeded epitaxial growth of Si over SiO2 is demonstrated in two types of structures. In the first case, rectangular pads of deposited Si were recessed into a thick SiO2 film. Narrow (≃ 5μm) via holes in SiO2 linked the pads with the bulk Si substrates. In the second embodiment, SiO2 patterns were recessed into the Si wafers which were then covered with a continuous 0.5μm poly-Si layer. In both cases, nearly planar geometries were maintained by use of local oxidation and etching techniques. Silicon was recrystallized with a focused Ar+ laser beam. Depending on the scanning conditions and the Si pattern geometry, single crystal growth propagated between 30 and >500μm. The factors influencing the extent and quality of the crystallized regions are discussed.