Thermal Deformation of Glass Backplane during Flash Lamp Crystallization Process of Amorphous Silicon

The flash lamp annealing (FLA) process has been considered highly promising for manufacturing low-temperature polysilicon on large-scale backplanes. Based on a theoretical estimation, this study clarifies the critical mechanisms of glass backplane deformation during the FLA process. A simulation using a commercial FEM code with viscoelastic models shows that the local region, whose temperature is larger than the glass softening point, undergoes permanent structural shrinkage owing to stress relaxation. For larger backplanes (4th Gen), structural shrinkages and gravitational deflection are critical to deformation in the FLA process, resulting in an "M" shape; in smaller backplanes (0th Gen), the latter is negligible, resulting in a "U" shape.