Method of forming thin-film transistor liquid crystal display having a

Abstract

Methods of forming thin-film transistor liquid crystal display devices include the steps of forming a semiconductor active layer on a face of a transparent substrate and then forming a gate electrode insulating layer on the semiconductor active layer. The gate electrode insulating layer is then patterned to expose a first portion of the semiconductor active layer. A gate electrode is also formed on the gate electrode insulating layer, opposite the semiconductor active layer. In addition, a pixel electrode is formed to be electrically coupled to the exposed first portion of the semiconductor active layer. Preferably, the steps of forming the gate electrode and pixel electrode are performed simultaneously by forming a transparent conductive layer on the patterned gate electrode insulating layer and then patterning the transparent conductive layer to define a transparent gate electrode and a transparent pixel electrode. The transparent conductive layer may comprise a material selected from the group consisting of indium tin oxide (ITO) and zinc oxide (ZnO). Dopants of first conductivity type are also preferably implanted into the semiconductor active layer, using the gate electrode and the pixel electrode as an implant mask, and then a laser annealing step is performed to recrystallize the channel portion of the active layer and activate the dopants in the source and drain regions.