Methods for forming liquid crystal displays including thin film transistors and gate pads having a particular structure

TLDR: In this article, the first and second metal layers are patterned to provide a gate electrode on a TFT area of the substrate and a gate pad on a pad area of a substrate.

Abstract: A method for forming a liquid crystal display includes the steps of depositing a first metal layer on a substrate, and depositing a second metal layer on the first metal layer opposite the substrate. The first and second metal layers are patterned to provide a gate electrode on a TFT area of the substrate and to provide a gate pad on a pad area of the substrate. An insulating layer is formed on the gate electrode and on the gate pad, and on the substrate, and a semiconductor layer is formed on the insulating layer opposite the gate electrode wherein the semiconductor layer includes a channel region opposite the gate electrode and first and second spaced apart source/drain regions separated by the channel region. First and second spaced apart metal source/drain electrodes are formed on the respective first and second spaced apart semiconductor source/drain regions, and a protective layer is formed on the exposed portion of the first semiconductor layer opposite the substrate, on the first and second metal source/drain electrodes opposite the substrate, and on the insulating layer opposite the gate pad. A first contact hole is formed in the protective layer exposing a portion of one of the source/drain electrodes, and a second contact hole is formed in the protective layer and the insulating layer exposing a portion of the gate pad wherein the second contact hole exposes only a surface portion of the gate pad opposite the substrate. A transparent conductive layer is formed on the protective layer opposite the substrate, and the transparent conductive layer is patterned to form a pixel electrode electrically connected to the exposed portion of the source/drain electrode and to the exposed portion of the gate pad.