Fabrication of Polycrystalline Silicon Thin Film Transistors in Array Patterns by Field-Aided Lateral Crystallization Technique

As a crystallization process, the field-aided lateral crystallization (FALC) technique has some outstanding advantages, such as high crystallization rate and low process temperature. In this study, an array of polycrystalline silicon thin film transistors (TFTs) was fabricated on a coming 1737 glass substrate using Ni catalyst. The electric field applied through common electrodes connected to the source and drain led to directional crystallization from the negative-electrode side to the positive-electrode side at 550 degrees C. The-applied electric field induced elongated grains with an accelerated crystal growth rate. As a result, each TFT channel showed not only a uniform crystallization rate but also homogeneous grain morphology. All of these crystallization behaviors are attributed to the electrical properties of the TFT array such as field effect mobility, threshold voltage, and on/off current ratio.