Giant-Lateral-Growth of SiGe Stripes on Insulating-Substrate by Self-Organized-Seeding and Rapid-Melting-Growth in Solid-Liquid Coexisting Region

Formation of SiGe crystals with large-grain on insulating-substrates is desired to achieve high-speed thin-film-transistors (TFT). We examine rapid-thermal annealing (950-1100 degrees C) of a-Si0.15Ge0.85-stripe (2-15-mu m-stripe-width) on insulator structures in solid-liquid-coexisting temperature-region. Formation of Si-rich micro-crystal-nuclei during annealing is clearly evidenced, where Si concentration and areal-density of micro-crystals are uniquely determined by annealing-temperature. Such self-organized-seeding enables lateral rapid-melting-growth from micro-crystals during cooling. The micro-crystals density per-unit-length is proportional to stripe-width, which results in enlargement of lateral-growth-length by narrowing stripe-width. Consequently, giant-lateral-growth of SiGe grains (similar to 300-mu m-length, 0-40%-Si-concentration) are achieved for narrow-stripe-width of 2 mu m at 1050 degrees C. This technique facilitates advanced TFT for high-performance system-in-displays. (C) 2014 The Electrochemical Society. All rights reserved.