Effects of Gate Insulator on Thin-Film Transistors With ZnO Channel Layer Deposited by Plasma-Assisted Atomic Layer Deposition

Zinc oxide (ZnO) thin films have attracted significant attention for application in thin-film transistors (TFTs) due to their specific characteristics, such as high mobility and transparency. The atomic layer deposition (ALD) thin film is deposited with alternating exposures of a source gas and oxidant. The ALD method keeps fabrication temperature of ZnO TFTs low. In this study, we investigated the effects of gate insulator properties on the performance of TFTs with a ZnO channel layer deposited by plasma-assisted ALD (PAALD). The TFTs with
${\hbox{Al}}_{2}{\hbox{O}}_{3}$
gate insulator indicated high performance (5.1
${\hbox{cm}}^{2}/{\hbox{V}}\cdot{\hbox{s}}$
field effect mobility) without thermal annealing. This result indicated a high-performance ZnO TFT with films deposited by PAALD can be obtained at temperatures below 100
$^{\circ}{\hbox{C}}$
.