| This dissertation documents the demonstration, development, and characterization of a new excimer laser crystallization process called sequential lateral solidification (SLS). The SLS process can provide thin-film materials with previously unavailable microstructures, such as location-controlled single-crystal islands and other low-defect-density engineered crystalline microstructures in thin silicon films on substrates that cannot withstand high-temperature processing. These materials are well-suited for making high-performance thin-film transistor (TFT) devices, and have important applications in several TFT-based technologies, such as active-matrix liquid-crystal displays (AMLCDs) and active-matrix organic light-emitting displays (AMOLEDs).; The concept for the SLS process originated from a previous study of the mechanisms of excimer-laser-induced phase transformations in thin silicon films, and is based on the superlateral growth (SLG) phenomenon. After a brief review of other crystallization technologies, the conceptual framework for the SLS process is introduced, implementation schemes and options are discussed, and the equipment that was used to conduct the process is presented. Initial efforts for demonstrating the viability of the process are discussed; the results from a number of different experiments that demonstrate the process are presented. A couple of different microstructures predicted by the model are verified by these results, including the directionally solidified columnar microstructure and the single-crystal island microstructure. In connection with these experiments, the factors that are relevant to the process are discussed, and the conditions for successful execution of the process are given.; The external parameter space of the SLS process was characterized in a systematic fashion using two different sets of equipment. The effects of the relevant experimental external parameters—film configuration, beam-patterning, energy density, and between-pulse translation distance—on the process and the resulting microstructure are presented.; A quantitative mathematical model of the process was developed, based on the SLG model, and was used to study the effects of stochastic variables such as the pulse-to-pulse laser beam energy fluctuation. Two approaches were taken: a Monte Carlo simulation, and an analytical treatment based on probability distributions. The predictions of the model are discussed, and are found to match the results of the parametric experiments. |
