High-Performance Indium Oxide Thin-Film Transistors With Aluminum Oxide Passivation

In this letter, high-performance thin-film transistors (TFTs), with indium oxide (In
₂
O
₃
) as front channel layer, high permittivity ZrO
₂
as dielectric layer, and aluminum oxide (Al
₂
O
₃
) as passivation layers were integrated by a fully solution process. It is found that the incorporation of Al
₂
O
₃
passivation layer gives rise to a sharp decrease in the off current (I
_off
) and a corresponding increase in the on/off current ratio (I
_on
/I
_off
) of the TFTs, compared to that without Al
₂
O
₃
passivation. Furthermore, the thickness effect of the passivation layer on the performance of In
₂
O
₃
/ZrO
₂
TFTs has been investigated systematically. The In
₂
O
₃
/ZrO
₂
TFTs with optimized Al
₂
O
₃
passivation layers can be operated at 3 V with high performance, including a high field-effect mobility of 21.22 cm
²
N s, a large I
_on
/I
_off
of 10
⁷
and a negligible hysteresis (~0 V). This work demonstrates an effective strategy for the construction of high performance TFTs by incorporating the passivation layer.