Patent ID: 7470572
Filing Date: 2008-12-30
Classification: G02F,H01L

Abstract:
1. A method for forming a thin film transistor liquid crystal display (TFT-LCD), the TFT-LCD having at least one thin film transistor (TFT) and one storage capacitor (Cs), the method comprising the steps of: providing a substrate; depositing a first conductive layer and a second conductive layer above the substrate to form a gate electrode of the TFT and a bottom electrode of the storage capacitor; forming an insulating layer on the first and second conductive layers and the substrate; depositing a semiconductor layer and a doped silicon layer on the insulating layer; forming a sacrifice layer with an island shape on the doped silicon layer, and the sacrifice layer being positioned directly above the first conductive layer; forming a metal layer covering the sacrifice layer and the doped silicon layer; patterning the metal layer to form a source electrode and a drain electrode above the first conductive layer as well as to form a shielding metal layer above the second conductive layer, a channel being defined between the source electrode and the drain electrode to expose the sacrifice layer in the channel, a capacitor region being defined as a portion of the substrate covered by the shielding metal layer, and a non-TFT region being defined as a portion of the substrate not covered by the source electrode, the drain electrode, the capacitor region, and the channel so as to expose the doped silicon layer thereon; using the source electrode, the drain electrode, and the shielding metal layer as a mask to perform the following etching processes at the same time: (a) removing the doped silicon layer and the island-shaped sacrifice layer in the channel so as to expose the semiconductor layer therein, and (b) removing the doped silicon layer and the semiconductor layer in the non-TFT region so as to expose the insulating layer thereon; and forming a passivation layer to cover the source electrode, the drain electrode, the channel, and the capacitor region.