Fast Low-Temperature Plasma Process for the Application of Flexible Tin-Oxide-Channel Thin Film Transistors

In this study, we demonstrated a
p
-type and
n
-type SnO TFTs on flexible polyimide substrate. The fabricated
p
-type SnO TFT showed a high
$I_{\rm on}/ I_{\rm off}$
of
$ \text{5.7}\, \times \,\text{10}^{5}$
and a high
$\mu _{{\rm{FE}}}$
of
${\text{10.7 cm}}^{2}\,{\text{V}}^{-1}\,{\text{s}}^{-1}$
. Through optimizing the oxygen plasma condition, the
n
-type channel TFT transfered from prime
p
-type channel exhibits excellent characteristics, including a high on/off current ratio of
$\rm{6.6}\,\times\,10^{3}$
, a low threshold voltage of −0.13 V, and a very high field-effect mobility of
${\text{28 cm}}^{2}\,{\text{V}}^{-1}\,{\text{s}}^{-1}$
. This proposed low-temperature oxygen plasma treatment shows the potential in simplification of TFT process that can achieve
n
-type and
p
-type TFTs under the same device process.