Oxide thin film transistor

An oxide thin-film transistor (TFT) is a particular kind of field-effect transistor made by depositing thin films of a semiconductor active layer as well as the dielectric layer and metallic contacts over a supporting substrate. The principal difference between amorphous silicon TFT and Oxide TFT is that the material of the electron channel is oxide or amorphous silicon. A common substrate is glass, since the primary application of TFTs is in liquid crystal displays and organic light emitting displays (OLEDs). This differs from the conventional transistor where the semiconductor material typically is the substrate, such as a silicon wafer. TFT electrical performance is dramatically degraded if a zinc–tin–oxide TFT is covered with a dielectric layer and does not undergo both types of annealing. In addition to silicon dioxide, successful passivation of zinc–tin–oxide TFTs is accomplished using thermally evaporated calcium fluoride, germanium oxide, strontium fluoride, or antimony oxide as passivation.