A Deep UV Sensitive ${\rm Ta}_{2}{\rm O}_{5}/{\rm a-IGZO}$ TFT

The authors report the fabrication of a deep-ultraviolet (deep-UV) sensitive a-IGZO thin-film-transistor (TFT) with a Ta
₂
O
₅
gate dielectric. It was found that carrier mobility, threshold voltage and subthreshold swing were 48.5 cm
²
/Vs, 1.25 V and 0.49 V/decade, respectively, when measured in dark. It was also found that measured current increased from 1.5×10
^-9
A to 5.56×10
^-5
A , as we illuminated the sample with λ = 250 nm UV light when V
_G
was biased at 0 V. Furthermore, it was found that deep-UV-to-visible rejection ratio could reach 1.0×10
⁶
for the fabricated Ta
₂
O
₅
/a-IGZO TFT.