Abstract: There is provided a thin-film transistor being capable of reducing dispersion in threshold voltage and a method of fabricating the same. The thin-film transistor includes an insulating undercoating layer formed for a substrate, a semiconductor active layer of polycrystalline silicon formed on the insulating undercoating layer, and a gate electrode formed insulated on the semiconductor active layer, the insulating undercoating layer being of a silicon oxide film layer formed using TEOS as a material and by a plasma CVD method. Preferably, the concentration of carbon atoms of the silicon oxide film layer is within a range of 6×1019 atoms/cm3 to 1×1020 atoms/cm3 and the concentration of nitride atoms is not more than 3×1019 atoms/cm3.

Abstract: A method for forming a contact hole in an active matrix substrate, the method comprising steps of: (a) depositing an insulating film covering a first electrode provided on a substrate and the substrate; (b) forming a contact hole by patterning said insulating film by means of dry etching; and (c) forming a second electrode, and contacting the second electrode with the first electrode; wherein in the step (b) after forming a contact hole by dry etching, a surface treatment by plasma etching or reactive ion etching with oxygen gas under a condition in which a pressure P is in a range of 100 Pa to 400 Pa is performed.

Abstract: A method of providing a contact hole including (a) depositing a first conductive film on a substrate and patterning the first conductive film to form a first electrode line, (b) depositing an insulating film on the first electrode line and the substrate, (c) forming a contact hole in the insulating film over a top surface of the first electrode line, and (d) depositing a second conductive film on the insulating film and the contact hole and patterning the second conductive film to form a second electrode line, wherein a surface of the first conductive film is subjected to an oxidizing operation in step (a) so that a contact resistance of the contact hole is lowered.