Self-Limiting Formation of NiSi₂ to Improve NiSi₂-Induced Crystallization and Develop High-Performance Poly-Si FETs With Self-Aligned NiSi₂-Induced Lateral Crystallization

Abstract-In this work, to improve NiSi2-induced crystallization (SIC), NiSi2 formation was experimentally explored with three different silicidation processes. The nucleation and morphology of NiSi2 are significantly improved via lowering the heating rate of two-step rapid thermal processing (RTP). Further adopting the self-limiting formation method, a uniform NiSi2 with an ultra-thin thickness of 38 Å is attained. This formed NiSi2 warrants an increased crystallization and a reduced Ni contamination when used as the inductor to crystallize amorphous Si. Subsequently, integrating this NiSi2 formation scheme to crystallize the channel in a self-aligned manner, high-performance n-type poly-Si field-effect transistors are developed, showing superior electrical characteristics, including high mobility of 69.1 cm2 / V-s, steep subthreshold swing (SS) of 111.47 mV / dec, low leakage current of 4.67 pA / $\mu$ m, and a large on-off current ratio of $2.51 \times 10^7$ .