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The surface morphology in polycrystalline silicon (poly-Si) film is an issue regardless of whether conventional excimer laser annealing (ELA) or the newer metal-induced lateral crystallization (MILC) process is used. This paper investigates the stress distribution while undergoing long-term mechanical stress and the influence of stress on electrical characteristics. Our simulated results show that the nonuniform stress in the gate insulator is more pronounced near the polysilicon/gate insulator edge and at the two sides of the polysilicon protrusion. This stress results in defects in the gate insulator and leads to a nonuniform degradation phenomenon, which affects both the performance and the reliability in thin-film transistors (TFTs). The degree of degradation is similar regardless of bending axis (channel-length axis, channel-width axis) or bending type (compression, tension), which means that the degradation is dominated by the protrusion effects. Furthermore, by utilizing long-term electrical bias stresses after undergoing long-tern bending stress, it is apparent that the carrier injection is severe in the subchannel region, which confirms that the influence of protrusions is crucial. To eliminate the influence of surface morphology in poly-Si, three kinds of laser energy density were used during crystallization to control the protrusion height. The device with the lowest protrusions demonstrates the smallest degradation after undergoing long-term bending.

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This paper presents the formation of iridium nanocrystals (Ir-NCs) embedded in SiO2 matrix and it can be used for potential applications of nonvolatile memory devices. The NC formation is investigated by varying Ir film thickness; and the thermal agglomeration is also studied by applying various annealing temperatures and process time. The results of systematic characterization including capacitance-voltage, transmission electron microscopy, and x-ray photoelectron spectroscopy show that the high work-function (5.27 eV) metallic-NCs have a highly thermal stability (up to 900 °C) and the resulted Al/SiO2/Ir-NCs/SiO2/Si/Al stack can have a good retention ability and significant hysteresis window of 17.4 V.

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