Every software package contains a full set of examples suitable for that version and are installed with the software. If you see examples here that are not in your installation you should consider updating to a later version of the software. These examples can be used by beginners and advanced users for product evaluation, teaching purposes, and self-training.
Required Modules
Victory Device:
- 2D Simulator
- 2D TFT
In this example, we demonstrate the temperature properties of amorphous IGZO TFT. We reproduced the measured transfer curve as well as mobility with temperature through newly developed IGZO.TOKYO model.
Victory Device Structure
The IGZO thickness is 40nm and channel length is 40um. The mesh structure is generated with x.mesh and y.mesh statement. Each generated mesh is defined with material usimg region statement. The electrode and doping statement were used to define metal electrode and channel doping. For intrinsic IGZO n-type doping, we assumed uniform 8e15/cm^3 concentration.
Models
We used fixed trap states for the IGZO sub-gate states with temperature. It is validated from experimental data, in which the extracted DOS is not significantly changed during temperature change. The IGZO band gap is 3.1 eV and constant band edge mobility is assumed to be 14. During transfer curve simulation, threshold voltage is defined at drain current of 1e-10 Ampere and subthreshold voltage and linear mobility are extracted.
To enable new IGZO.TOKYO model, use mobility statement and model flag name “IGZO.TOKYO “.
mobility IGZO.TOKYO mun=$mue0 mup=0.01 tmun=0 tmup=0 \
igzo.gamma0=$gm0 igzo.tgamma=$tgm igzo.ncrit=$necr
Other related parameters are defined with set command in the *_VD_aux.in file.
Simulation Results
Deck *.in file is simple doe file which select different temperature from 253K to 393K. It loads *_VD_aux.in file, which simulates the temperature effect on IGZO TFT. After completion, it will plot the mobility vs. temperature curve, transfer curve vs. temperature as well as overlaying with experimental data, and threshold voltage shift with temperature, which is automatically saved in *_VD_temperature.dat file during simulation.
References:
[1] K. Abe et. al., “Mobility- and temperature-dependent device model for amorphous In-Ga-Zn-O thin-film transistors, ” Thin Solid Films 559 (2014) 40-43
[2] “Temperature Properties of Amorphous In-Ga-Zn-O Thin-Film Transistors with a new Mobility Model ” Simulation Standard, December 2017, Silvaco Inc.
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