Effect of ITO Serving as a Barrier Layer for Cu Electrodes on Performance of a-IGZO TFT

In this letter, we propose a strategy to improve the electrical performance of amorphous In-Ga-Zn-O (a-IGZO) thin film transistor (TFT) with the copper (Cu) electrodes by depositing a 30-nm thick In-Sn-O (ITO) interlayer on top of IGZO layer to suppress Cu migration. As a result, the a-IGZO TFT with ITO interlayer exhibits enhanced electrical performance (V
_TH
of 1.5 V, μ
_FE
of 11.5 cm
²
/Vs, SS of 0.2 V/dec, I
_ON
/I
_OFF
of 2.4 × 10
¹⁰
, and R
_C
W: 18 cm).