Self-aligned thin film transistor and fabrication method thereof

Abstract

Disclosed are a self-aligned thin film transistor capable of simultaneously improving an operation speed and stability and minimizing a size thereof by forming source and drain electrodes so as to be self-aligned, and a fabrication method thereof. The method of fabricating a thin film transistor according to an exemplary embodiment of the present disclosure includes: forming an active layer, a gate insulator, and a gate layer on a substrate; forming a photoresist layer pattern for defining a shape of a gate electrode on the gate layer; etching the gate layer, the gate insulator, and the active layer by using the photoresist layer pattern; depositing a source and drain layer on the etched substrate by a deposition method having directionality; and forming a gate electrode and self-aligned source electrode and drain electrode by removing the photoresist layer pattern.

What is claimed is: 
     
         1 . A self-aligned thin film transistor, comprising:
 a substrate;   an active layer formed on the substrate;   a source electrode and a drain electrode formed on the substrate and self-aligned in both side surfaces of the active layer;   a gate insulator formed on the active layer; and   a gate electrode formed on the gate insulator.   
     
     
         2 . The self-aligned thin film transistor of  claim 1 , wherein the active layer is formed of oxide containing at least one element of zinc (Zn), indium (In), gallium (Ga), tin (Sn), and aluminum (Al). 
     
     
         3 . The self-aligned thin film transistor of  claim 1 , wherein the gate layer is formed of a material containing at least one of aluminum (Al), an aluminum alloy (Al alloy), tungsten (W), copper (Cu), nickel (Ni), chrome (Cr), molybdenum (Mo), titanium (Ti), platinum (Pt), tantalum (Ta), indium tin oxide (ITO), and indium zinc oxide (IZO).