Kink effect in short-channel polycrystalline silicon thin-film transistors

Abstract

Role of gate oxide thickness in controlling short channel effects in polycrystalline silicon thin film transistors Appl. Phys. Lett. 95, 033507 (2009);

(Invited) Short Channel Effects and Drain Field Relief Architectures in Polysilicon TFTs

“…5 shows the dependence of V T upon the channel length for three different drain bias: it is clear that as V ds is increased the V T curves tend to spread out, denoting an increased V T roll-off with L. This is a finding in contrast with what is observed in SOI devices, where increasing V ds reduces the V T roll-off as channel length is reduced [16]. To clarify the short channel effects we used numerical simulations, adopting as already mentioned, the effective medium approximation [11,14]. The device characteristics were reproduced very accurately, using the set of optimized parameters reported in ref.…”

“…The kink effect was analyzed by using two-dimensional numerical simulations and by adopting the effective medium approximation. By using a single set of optimized parameters for the density of states (DOS) and impact ionization parameters [14], it was possible to accurately reproduce the kink effect variation with L, as can be realized by comparing experimental (Fig. 1a) and simulated ( Fig.…”

P-type and N-type multi-gate polycrystalline silicon vertical thin film transistors based on low-temperature technology

“…Nevertheless, the two types of VTFTs have shown symmetric I ON and I OFF , which demonstrates the feasibility for CMOS-like VTFT circuit applications as inverters or oscillators. Figure 6 (c) shows the output characteristics of the fabricated VTFTs, the kink effect prevents the saturation of the drain current, which could be suppressed by increasing the channel length and thus undoped polycrystalline silicon thickness [14], and by improving the crystalline quality of the active layer on the sidewalls. By combining the analysis of on-current I ON and off-current I OFF , we can conclude that, for a fixed tooth width W t , the I ON /I OFF ratio follows the equation:…”

(Invited) Downscaling Issues in Polycrystalline Silicon TFTs

“…Kink effect was analyzed by using two-dimensional numerical simulations and by adopting the effective medium approximation. By using a single set of optimized parameters for the density of states (DOS) and impact ionization parameters [12] (see table I), it was possible to accurately reproduce kink effect variation with L, as can be realized by comparing experimental (Fig. 4a) and simulated ( Fig.…”