Improved IGZO-TFT structure Using High-k Gate Dielectric Materials

In this paper an IGZO-TFT based on High-K gate dielectric is simulated using TCAD software. We report on the electrical properties of amorphous indium-gallium-zinc-oxide thin-film transistors (TFTs) with a range of oxides (SiO
₂
, HfO
₂
, ZrO
₂
, Al
₂
O
₃
or TiO
₂
) gate dielectrics materials IGZO-TFT with TiO
₂
layer dielectric exhibited threshold voltage V
_th
of 2 V, a Saturation mobility μ
_sat
of 4.51 cm
²
/Vs, Subthreshold swing SS of 0.075 V/dec, and a current ratio I
_on
/I
_off
of 1.244E13. These characteristics make it suitable for use as a switching transistor in low-power application, furthermore a temperature-dependent transfer characteristic of the a-IGZO TFT, ranging from 300 to 500 k. show that more the dielectric constant of the oxide gate dielectric is high, more we get a high current.