Performance Analysis of Top Gate Top Contact TFT Using Different Dielectric Layers

Abstract

Thin film transistors (TFT) have been gaining special attention from researchers in recent years because they are seen as an alternative to traditional MOSFET for future electronic device development. In this manuscript, the performance characteristics of n-channel Indium-Galium-Zinc-Oxide (IGZO) Top Gate Top Contact (TGTC) Thin Film Transistors (TFTs) for various insulating materials including Al₂O₃, Ta₂O₅, HfO₂, Si₃N₄, SiO₂, and Y₂O₃ are investigated and compared. This is followed by a comparison of p-type pentacene-based TGTC Organic Thin Film Transistors (OTFT). During simulation tests, the Silvaco Atlas tool is employed, and the I-V characteristic curve is analyzed to discover the important parameters. The proposed TFT's competency is demonstrated by extensive simulation results that contrast it with other models of a similar nature concerning threshold voltage, current ratio, subthreshold slope, mobility and Figure of Merit (FoM). The results demonstrate a trade-off between mobility and current ratio concerning the permittivity of the dielectric layer, with tantalum oxide (Ta₂O₅) providing the best outcomes in terms of FoM. According to simulation testing, the tantalum pentoxide (Ta₂O₅) gate insulating layer based on IGZO surpasses its rivals including the p-channel pentacene-based OTFT by offering mobility of 1.47 cm²V^-1s^-1, a current ratio of 1.36×10⁶ and FoM of 198.87.