A Hybrid Approach for Obtaining Orientation-Controlled Single-Crystal Si Regions on Glass Substrates

摘要

We have previously shown that location-controlled single-crystal regions can be obtained by implementing a version of the sequential lateral solidification process referred to as dot-SLS. Performed on an amorphous Si precursor, however, the process results in regions having an apparently random surface crystal-orientation distribution that may negatively impact the uniformity of resulting devices. In this paper, we demonstrate one approach to control the surface orientation of dot-SLS processed regions. We accomplish this in a simple manner by performing the process on textured polycrystalline Si precursor films that were, in turn, obtained using laser processing of as-deposited amorphous Si films. This hybrid approach is possible and effective because the dot-SLS process allows for preserving the original texture of the "seed" crystals, while successfully removing all random high-angle grain boundaries within the laterally solidified regions. We identify and utilize two specific and well-known laser-processing techniques for obtaining highly (100) or (111) surface textured polycrystalline Si films. The results from dot-SLS experiments performed on (100) textured films — obtained through "mixed-phase" zone-melting recrystallization using a continuous-wave laser — were found to be particularly significant as the growth from {100} surface-oriented seeds resulted in single-crystal regions that were predominantly free of any planar defects.