Compact Modeling and Parameter Extraction for Oxide and Organic Thin Film Transistors (TFTs) from 150K to 350K

B. Iniguez (Univ. Rovira i Virgili, Spain)

We review the physics and modeling of Organic and Oxide Thin-Film Transistors (TFTs). We analyze the electrostatic and charge transport mechanisms in organic TFTs (OTFTs) and Amorphous Oxide Semiconductor TFTs (AOS TFTs). We demonstrate that compact OTFTs and AOS TFTs model can be developed by using analytical approximate solutions of Poisson's equation considering exponential Density of States (DOS) and on a transport model based on the combination of carrier hopping between localized states with drift current of free carriers. The resulting field-effect mobility expressions are power laws of the gate voltage overdrive. Analytical expressions can be found from the deep subthreshold regime to the well above threshold one. Moreover, we discuss direct methods to extract model parameters. We show that most key parameters are extracted applying an integral operator to the measured drain current values. We analyze drain current characteristics from 150K to 350K and show how the extracted parameters vary with temperature.We also present a capacitance modeling framework consistent with the developed drain current model. Finally, we study the 1/f noise in OTFTs in AOS TFTs and we identify the physical mechanisms originating it.