Simulating the I‐V characteristics of an ultrathin IGZO ‐based thin film transistor using finite element method

Abstract Thin film transistors (TFTs) are ranked as one of the promising field‐effect transistors in the electronic industry. TFTs showed a great potential in many applications where liquid crystal displays, touchscreens, and biosensors are of the leading. In the current study, we are demonstrating a numerical carrier transport model based on finite element method (FEM), to investigate InGaZnO (IGZO) based TFTs. Amorphous silicon TFT has been simulated as a bare device. The impact of scaling down the dimension of the TFT, up to 30 nm channel length, on the output performance characteristics of the transistor has been addressed. Additionally, the effects of active semiconductor layer doping concentration and oxide layer thickness have been investigated. Moreover, a novel approach is introduced to correlate the selected input design parameters with a set of characteristic outputs including threshold voltage, on/off current ratio, and subthreshold swing. The proposed model correlates input and outputs using a characteristic matrix with nine coefficients, making it possible to predict, that is, interpolate, the characteristic outputs within the system boundaries. The suggested model was verified with respect to input data as well as data from the literature showing a very acceptable agreement.