Abstract: A method of producing thin film transistor arrays and having at least 7 steps including: a first step of forming a first electrode layer uniformly over an insulating substrate; a second step of forming electrodes, such as drain and source electrodes and bus bars with a desired pattern by photoetching the first electrode; a third step of forming a uniform semiconducting layer on the surface of the substrate having the patterned electrodes; a fourth step of successively forming a uniform insulating layer over the uniformly deposited semiconducting layer while keeping the array in a vacuum; a fifth step of photoetching the uniformly deposited insulating layer into a desired pattern; a sixth step of photoetching the uniform semiconducting layer into the same pattern as the patterned insulating layer; a seventh step of forming a second electrode uniformly over the surface having the patterned electrodes and insulating layer; and an eighth step of photoetching the uniformly deposited second electrode into a desired