Abstract: A method of making a thin film transistor is described incorporating the steps of forming a gate electrode, a layer of insulating material, a layer of buffer material, a layer of semiconductor material, a source electrode and drain electrode. The invention reduces the problem of variation in threshold voltage of thin film transistors due to external stress such as the gate voltage or temperature.

Abstract: A thin film transistor is described incorporating a gate electrode, a layer of insulating material, a layer of buffer material, a layer of semiconductor material, a source electrode and drain electrode. The invention reduces the problem of variation in threshold voltage of thin film transistors due to external stress such as the gate voltage or temperature.

Abstract: A method of forming a screw thread on one portion of a crankshaft and the like wherein the one portion of the shaft is worked on to provide thereto a diameter of a value greater than the value of the diameter of the one portion of the shaft before it is subjected to roll threading plus the value of the thickness of a hard, thin surface layer expected to be formed by carburizing on the whole of the shaft. Then, carburizing is performed to form the hard, thin surface layer on the whole of the shaft. Thereafter, the one portion of the shaft is subjected to grinding or machining to remove the hard, thin surface layer therefrom to reduce the diameter of the one portion of the shaft to a level conforming to the diameter thereof before roll threading is performed on the one portion of the shaft, and roll threading is performed on the one portion of the shaft from which the hard, thin surface layer is removed, to provide the shaft with a threaded portion.

Abstract: A photoconductive film comprising a photo-conductive layer which is mainly made of selenium and a region added with tellurium in a direction of the thickness of the layer, wherein at least either one of a portion in a direction of hole flow of said region added with tellurium and a portion in the hole flow of another region which is located adjacent to said region added with tellurium is doped with at least one member selected from the group consisting of an oxide, a fluoride and elements which belong to the group II, III and VII, which are capable of forming a negative space charge in selenium, at a concentration in a range of 10 ppm to 1% by weight on an average. Typical examples of such oxide, fluoride and element include CuO, In.sub.2 O.sub.3, SeO.sub.2, V.sub.2 O.sub.5, MoO.sub.3, WO.sub.3, GaF.sub.2 InF.sub.3, Zn, Ga, In, Cl, I, Br and the like. The after image characteristic ascribable to incident light of high intensity can be significantly improved.