Patent ID: 7566904

Claim:
A thin film transistor, comprising: a semiconductor thin film including zinc oxide; a protection film formed on an entire upper surface of the semiconductor thin film and having a plan-view shape that is substantially the same as a plan-view shape of the semiconductor thin film; a gate insulating film formed on the protection film; a gate electrode formed on the gate insulating film above the semiconductor thin film; a source electrode and a drain electrode formed under the semiconductor thin film so as to be electrically connected to the semiconductor thin film, the source electrode and the drain electrode having portions protruding at a periphery of the semiconductor thin film and the protection film; and ohmic contact layers made of n type zinc oxide which are respectively provided on upper surfaces of the source electrode and the drain electrode under the semiconductor thin film, wherein surrounding end surfaces of the ohmic contact layers have substantially a same shape as surrounding end surfaces of the semiconductor thin film and the protection film except end surfaces of the ohmic contact layers, which face each other, are formed in a same shape as end surfaces of the source electrode and the drain electrode that face each other, and wherein the gate insulating film covers peripheral side surfaces of the semiconductor thin film, the protection film and the ohmic contact layers, and outer surfaces of the protruding portions of the source electrode and the drain electrode.