Provided are a method of manufacturing a ZnO
semiconductor layer for an electronic device, which can control the size of crystals of the ZnO
semiconductor layer and the number of carriers using a
surface chemical reaction between precursors, and a
thin film transistor (TFT) including the ZnO
semiconductor layer. The method includes: (a) loading a substrate into a chamber; (b) injecting a Zn precursor into the chamber to adsorb the Zn precursor on the substrate; (c) injecting an
inert gas or N2 gas into the chamber to remove the remaining Zn precursor; (d) injecting an
oxygen precursor into the chamber to cause a reaction between the
oxygen precursor and the Zn precursor adsorbed on the substrate to form the ZnO semiconductor layer; (e) injecting the N2 gas or
inert gas into the chamber to remove the remaining
oxygen precursor; (f) repeating steps (a) through (e); (g) repeatedly
processing the surface treatment of the ZnO semiconductor layer using O2
plasma or O3; (h) injecting the N2 gas or
inert gas into the chamber to remove the remaining oxygen and Zn precursors; and (i) repeating steps (a) through (h) to control the thickness of the ZnO semiconductor layer. In this method, a transparent TFT is formed using a transparent substrate to enable manufacture of a
transparent display device, and a
flexible display device can be manufactured using a flexible substrate. Also, the
crystallinity of the ZnO semiconductor layer can be increased to improve the mobility of a TFT, and the number of carriers can be controlled to reduce a leakage current. Therefore, a ZnO semiconductor having excellent characteristics can be manufactured.