Wet Deposition Process for Thin-Film Transistors

Abstract

A wet thin-film process was applied for manufacturing thin-film transistors (TFTs) to improve the traditional dry deposition process which is time consuming and expensive. In this study, wet processes, such as the electroless deposition of silver (Ag) and the electrophoretic deposition (EPD) of Al2O3, were used to replace the dry process. Because of low resistivity, Ag was used as the conductive layer. This study demonstrates how the formation of Al2O3 ceramic thin film was deposited on Ag film by using the EPD process on a glass TFT substrate. The electrical and mechanical properties of the Ag film were examined according to the deposition time and sintering temperature. Nano-Al2O3 powders were prepared to form an insulation layer on the Ag film by using EPD. Stabilized electrophoretic suspensions at various pH values were prepared. Deposition times from 1 to 7 min were applied to obtain the various deposition conditions. EDP was followed by Ag deposition and Al2O3 sintering. A four-point probe and nanoindenter were used to examine the electrical resistivity and mechanical properties, respectively.