Patent ID: 6884569

Claim:
A method of manufacturing a TFT array comprising the following steps of: applying photoresist onto a film to be etched, forming a photoresist pattern of desired pattern by exposing and developing the photoresist using a photomask, etching the film using the photoresist pattern, removing a part of the photoresist pattern, and etching the film using the partly removed photoresist pattern, wherein the photomask comprises; a region A* in which illuminated light from an exposing machine during the exposure step is shade to limit the amount of illuminated light transmitting therethrough in order to leave the resist pattern through the step for partly removing the photoresist pattern, a region C* in which illuminated light from the exposing machine during the exposure step is transmitted to allow the sufficient amount of illuminated light transmitting therethrough in order to remove the photoresist through the step of developing, and a region B* in which a transmitting/shielding pattern having finer dimensions than resolution of the exposing machine is provided, so that the amount of light transmitting therethrough during the exposure step is intermediate between those in the region A* and C*, and wherein the transmitting/shielding pattern has a ladder-like shape in which at least three rectangular transmitting portion, each of which has a predetermined length and width, are arranged in a lengthwise direction thereof, and a dimensional precision of the transmitting pattern is ±0.1 μm at maximum.