n-and p-channel poly-Si thin-film transistors with fully Ni-self-aligned silicided ͑fully Ni-salicided͒ source/drain ͑S/D͒ and gate structure ͑n-and p-channel FUSA-TFTs͒ have been successfully fabricated on a 40 nm thick channel layer. The conventional poly-Si gate is replaced by the fully Ni-silicided gate, and the parasitic S/D resistance of the FUSA-TFTs is significantly reduced by the fully Ni-silicided S/D structure. The fully Ni-salicidation process is executed at a low temperature of 500°C for a short rapid thermal annealing time. Experimental results show that the FUSA-TFTs give increased on/off current ratio, improved subthreshold characteristics, less threshold voltage roll-off, lower parasitic S/D resistance, higher gate capacitance, and larger field-effect mobility than conventional TFTs. The FUSA-TFTs effectively suppress the floating-body effect and parasitic bipolar junction transistor action. The characteristics of the FUSA-TFTs are suitable for three-dimensional integration applications and high performance driver circuits in the active-matrix liquid crystal displays.Polycrystalline silicon thin-film transistors ͑poly-Si TFTs͒ have been widely used in many potential applications including threedimensional ͑3D͒ integration high density flash memories, pixel driving elements in active-matrix organic light emitting diodes and integrated peripheral driving circuits, and addressing elements of active-matrix liquid crystal displays ͑AMLCDs͒. 1-4 However, the output characteristics exhibit an anomalous increase in current in the saturation regime, often called the "kink" effect by analogy with silicon-on-insulator ͑SOI͒ devices. 5-7 This phenomenon can be attributed to the floating-body effect 8 and avalanche multiplication enhanced by grain boundary traps, 6 particularly in n-channel TFTs. With increasing drain voltage, the added drain current enhances impact ionization and the parasitic bipolar junction transistor ͑BJT͒ effect, which leads to a premature breakdown in return. 8 In the floating-body thin-film devices, the improved parasitic BJT effect can be achieved by using deep salicidation and a fully silicided source/drain ͑S/D͒ structure. 9,10 Due to low hole field-effect mobility, p-channel TFTs have a lower on-state current than n-channel TFTs. Nevertheless, p-channel TFTs have advantages, such as a lower off-state leakage current, slighter floating-body and kink effects, a weaker drain impact ionization, and a higher hot carrier reliability. In addition, thin-channel poly-Si TFTs have better device characteristics such as a small leakage current and a suppressed floating-body effect than thick-channel poly-Si TFTs. 11 However, a thin-channel film also leads to increased parasitic S/D resistance. Parasitic S/D resistances become an increasingly serious issue for thin-channel poly-Si TFTs and SOI devices. Several methods such as self-aligned silicide, selective tungsten-clad and metal-replaced junction technology have been proposed to reduce parasitic S/D resistance in thin-channel SOI devices an...
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