| Summary: | 碩士 === 國立清華大學 === 材料科學工程學系 === 91 === Recently, there are extensive studies on the fabrication of high quality and low process temperature polycrystalline silicon thin film by the nickel metal induced lateral crystallization (Ni-MILC) method. Our previous works indicated that, changing the curvature of nickel pattern would have serious impact on the crystallinity and quality of the induced crystallites. In this thesis, by using the high resolution transmission electron microscopy (HRTEM) and Energy Dispersive Spectrometer (EDS) analyses, we present the results of investigating the atomic structure evolution of the mechanism for nickel metal induced lateral crystallization of amorphous silicon.
For the rectangular nickel pattern, the [211] projected crystallites was found at the initial stage of crystallization and immediately transfer to the [110] orientation. The morphology of induced crystallites was straight and parallel to each other. As increasing of the curvature, dendrite-like crystallites with [110] projection grew wildly resulted in poor crystallinity due to the creation of large quantity of micro-twins. Moreover, during high process temperature, the density of micro-twins increased rapidly due to the dominating solid phase crystallization (SPC) process.
The Ni distribution profiles of NiSi2 precipitates in the leading front, was studied by using the EDS line scan function. It is the first time, the nickel distribution within the NiSi2 nodule and the interface area of NiSi2 / c-Si can be studied in detail. The results may provide the direct evidence to the solution of the long-time debating problem which is the nickel diffusion mechanism at the leading front upon MILC process.
|
|---|
