Transparent Thin-Film Transistors Using ZnMgO as Dielectrics and Channel

An enhancement-mode ZnMgO transparent thin-film transistor (TFT) is fabricated, in which cubic-phase ZnMgO (C-ZnMgO) is used as gate insulator and hexagonal-phase ZnMgO (H-ZnMgO) is used as channel. The multilayers of C-ZnMgO and H-ZnMgO are grown on patterned indium-tin-oxide-coated glass in successive fashion at low temperature. Capacitor-voltage characteristics measured across the gate show that the H-ZnMgO channel is n-type. The C-ZnMgO isolating layer demonstrates low leakage current characteristics, i.e., 4 times 10
^-7
A/cm
²
, at a bias of 10 V. The transparent TFTs display a typical channel mobility of 1.5 cm
²
V
^-1
s
^-1
and an on/off ratio of 10
⁴
.