Growth of Quasi-Single-Crystal Silicon–Germanium Thin Films on Glass Substrates by Continuous Wave Laser Lateral Crystallization

Abstract

Continuous wave laser lateral crystallization (CLC) technology was applied to grow silicon–germanium (SiGe) thin films on glass substrates. The crystal structure and distribution of Ge in the films were characterized by optical and electron microscopies. The compounding of Ge with Si and the use of CLC resulted in the growth of crystals with lengths greater than 100 µm in the laser-scanning region, whereas such long crystals were not formed in pure Si films. For Si0.7Ge0.3, the orientation of the crystal surface normal was along <111>. Most crystalline boundaries were Σ3 coincidence site lattices that were electrically inactive. High-angle or random grain boundaries were rarely found. Thus, the crystallized part can be regarded as a quasi-single crystal. The growth mode and segregation of Ge are discussed in terms of a constitutional undercooling model.