METHOD FOR MANUFACTURING A SUBSTRATE OF A THIN FILM TRANSISTOR FOR LIQUID CRYSTAL DISPLAY

摘要

PURPOSE: A method for manufacturing a substrate of a thin film transistor for liquid crystal display is provided to reduce manufacturing cost and process, by effectively decreasing the number of masks. CONSTITUTION: A gate interconnection including a gate line and a gate electrode connected to the gate line is formed on an insulating substrate. A gate insulating layer covering the gate interconnection is formed. A semiconductor layer is deposited on the gate insulating layer. A resistive contact layer is deposited on the semiconductor layer. A metal layer for a data interconnection is deposited on the resistive contact layer. A photoresist layer pattern having the first portion of the first thickness, the second portion of the second thickness thicker than the first portion and the third portion of no thickness are formed on the metal layer for the data interconnection. The metal layer for the data interconnection is firstly dry-etched to form a metal pattern for the data interconnection placed under the first and second portions by using the photoresist layer pattern as a mask. The resistive contact layer and the semiconductor layer are secondly dry-etched to form a resistive contact pattern and a semiconductor pattern placed under the metal pattern. The first portion is etched back to expose the fourth portion of the metal pattern for the data interconnection placed under the first portion. The fourth portion is thirdly dry-etched to form source/drain electrodes and a data line. The exposed resistive contact layer pattern is fourth dry-etched.