Analytical surface-potential-based drain current model for amorphous InGaZnO thin film transistors

Abstract

A fully analytical surface-potential-based drain current model for amorphous InGaZnO (α-IGZO) thin film transistors (TFTs) has been developed based on a Gaussian distribution of subgap states, with the central energy fixed at the conduction band edge, which is approximated by two exponential distributions. This model includes both drift and diffusion components to describe the drain current in all regions of operation. Using an empirical mobility relationship that depends on both horizontal and vertical electric field, it is demonstrated that the model describes accurately the experimental transfer and output characteristics, making the model suitable for the design of circuits using α-IGZO TFTs.

Low-frequency noise properties in Pt-indium gallium zinc oxide Schottky diodes

“…As for IGZO, the effective electron mass in the conduction band, m*, equals to 0.34m 0 , making N c ¼ 5.0 Â 10 18 cm À3 . 27,28 Since…”

Parameter extraction methodology for amorphous IGZO thin film transistors

“…The extraction methodology can be verified using the model developed in [12]. Figure 4 shows the transfer characteristics for different drain voltages of a typical a-IGZO TFT (W=40μm, L=26μm, tox=120nm).…”

“…We propose a new method for the extraction of the electrical parameters of α-IGZO TFTs based on an analytical drain current model that uses a Gaussian distribution of subgap states with the central energy fixed at the conduction band edge, which is approximated by two exponential distributions [12]. Each distribution corresponds to a different region of operation of the transistor.…”

“…Following a simple procedure the characteristic decay energies of the exponential distribution are calculated together with the threshold voltage, the onvoltage and the mobility of the α-IGZO TFTs. The experimental details are described elsewhere [13].…”

Accurate Analytical Physical Modeling of Amorphous InGaZnO Thin-Film Transistors Accounting for Trapped and Free Charges

“…The numerical models took into account the MTR and percolation transport in the semiconductor, showing that both trapped and free charges have to be considered in a-IGZO transistors. On the other hand, compact models [24]- [27] focused on the accurate description of the transistor electrical characteristics. A physical-based analytical model accounting for the a-IGZO transport physics and able to accurately predict the electrical characteristics of the transistor is still missing.…”