Performance enhancement of In-Ga-Zn-O TFTs using double-layer gate dielectric

We insert a low-temperature deposited (L-D) SiO
₂
between the high-temperature deposited (H-D) SiO
₂
and In-Ga-Zn-O (IGZO) active layer to enhance the TFT performance. Compared with the single SiO
₂
TFT, the performance of the double-layer SiO
₂
TFT shows obvious improvements, for instance, the saturation mobility (μ
_sat
) increases from 0.21 to 0.98 cm
²
/V.s, the subthreshold swing (SS) decreases from 1.05 to 0.506 V/decade and the I
_on
/I
_off
increases from 8.2×10
⁵
to 1.28×10
⁶
.