Method of manufacturing ZnO-based thin film transistor

Abstract

Provided is a method of manufacturing a ZnO-based thin film transistor (TFT). The method may include forming source and drain electrodes using one or two wet etchings. A tin (Sn) oxide, a fluoride, or a chloride having relatively stable bonding energy against plasma may be included in a channel layer. Because the source and drain electrodes are formed by wet etching, damage to the channel layer and an oxygen vacancy may be prevented or reduced. Because the material having higher bonding energy is distributed in the channel layer, damage to the channel layer occurring when a passivation layer is formed may be prevented or reduced.

1 . A ZnO-based thin film transistor (TFT) comprising:
 a substrate;   a gate insulating layer on the substrate;   a ZnO-based channel layer on the gate insulating layer;   a source electrode and a drain electrode on both sides of the ZnO-based channel layer; and   an over-etched portion recessed into the ZnO-based channel layer between the source electrode and the drain electrode.   
   
   
       2 . The ZnO-based thin film transistor of  claim 1 , wherein the ZnO-based channel layer includes at least one of a tin (Sn) oxide, a fluoride, and a chloride. 
   
   
       3 . The ZnO-based thin film transistor of  claim 2 , wherein the fluoride includes at least one selected from the group consisting of GaF 3 , InF 3 , and ZnF 2 . 
   
   
       4 . The ZnO-based thin film transistor of  claim 2 , wherein the chloride includes at least one selected from the group consisting of GaCl 3 , InCl 3 , and ZnCl 2 . 
   
   
       5 . The ZnO-based thin film transistor of  claim 1 , wherein the ZnO-based channel layer is formed of gallium-indium-zinc-oxide (GIZO). 
   
   
       6 . The ZnO-based thin film transistor of  claim 1 , wherein the source/drain electrodes are formed by a first etching and a second etching. 
   
   
       7 . The ZnO-based thin film transistor of  claim 1 , wherein the first etching uses a first etchant having phosphoric acid, nitric acid, and acetic acid as main components and the second etching uses a second etchant having water and hydrogen peroxide as main components and a trace of hydrogen fluoride (HF).