THIN FILM TRANSISTOR FOR LIQUID CRYSTAL DISPLAY DEVICE, CROSSOVER STRUCTURAL BODY AND MANUFACTURE THEREOF

摘要

PURPOSE: To form TFTs by a three mask method and to reduce the cost of production and to improve the yield thereof by forming a first conductive layer, second conductive layer and crossover structural body on an insulating substrate by using three masks. CONSTITUTION: A transparent electrode layer 12 and a doped layer 13 thereon are formed on the insulating substrate 11 and the first conductive layer 19 is formed on a dielectric layer 18 by using the first mask. The non-doped layer 17, the dielectric layer 18 and the first conductive layer 19 are selectively removed by using the second mask to constitute a part of the crossover structural body and the second conductive layer 21 is formed. The second conductive layer 21 is partly selectively removed by using the third mask, by which the part of the crossover structural body is formed. While four sheets of the masks are usually used to form the TFTs, the masks are decreased to three sheets, by which the yield is improve and the cost is reduced.