An array substrate includes a substrate, and a first TFT and a second TFT on the substrate. The second TFT is a low-temperature poly silicon TFT. The first TFT includes a buffer layer, a gate, a gate insulator layer, and a metal oxide semiconductor layer stacked on the substrate in that order. A source electrode and a drain electrode are separately positioned on the gate insulator layer and coupled to the metal oxide semiconductor layer of the first TFT. The metal oxide semiconductor layer partially covers the source electrode and the drain electrode.

An array substrate includes a substrate, a first TFT, a second TFT, and a third TFT. The first TFT includes a first channel layer on the substrate, a first gate insulator layer, a first gate electrode, a first dielectric layer, and a second dielectric layer. The second TFT includes a first semiconductor layer on the substrate, a second gate insulator layer, a second gate electrode, a third dielectric layer, and a second channel layer. The first channel layer is made of a semiconducting material containing polycrystalline silicon. The second channel layer is made of a semiconducting material containing metal oxide. The first dielectric layer is made of silicon nitride; the second dielectric layer and the third dielectric layer are made of silicon oxide.

A thin film transistor includes a polysilicon layer on a substrate, which includes a first area between second and third areas. A polysilicon layer is formed on the substrate, and a source electrode and a drain electrode are formed on the polysilicon layer in the first and third areas. Each of the source electrode and the drain electrode includes a metal silicide layer adjacent the polysilicon layer.

A thin film transistor is provided as follows. A first gate electrode and a second gate electrode are stacked on each other. A semiconductor layer is interposed between the first and second gate electrodes. A source electrode and a drain electrode are interposed between the semiconductor layer and the second gate electrode. A connection electrode connects electrically the first gate electrode and the second gate electrode. A first insulating film is interposed between the first gate electrode and the semiconductor layer. A second insulating film includes a first part interposed between the semiconductor layer and the second gate electrode and a second part interposed between the second gate electrode and the drain electrode. A third insulating film includes a first part interposed between the connection electrode and the second gate electrode.

A display substrate includes a first switching element electrically connected to a gate line and that extends in a first direction and electrically connected to a data line that extends in a second direction crossing the first direction, an insulation layer disposed on the first switching element, a shielding electrode disposed on the insulation layer and a pixel electrode that partially overlap the shielding electrode. The shielding electrode includes a first portion that overlaps the data line and extends in the second direction and a second portion that overlaps the gate line and extends in the first direction.

An array substrate for LCD devices and a method of manufacturing the same are provided. By using a structure where an empty space is secured in a data line area as in a DRD structure in which the number of data lines is reduced by half, a capacitance is sufficiently secured by forming a sub storage capacitor in the data line area of the empty space, and thus, an area of a main storage capacitor can be reduced. Accordingly, the cost can be reduced, and moreover, an aperture ratio can be enhanced.

A liquid crystal display device includes a data driving unit connected to a first data line disposed in a first direction, a gate driving unit connected to a first gate line disposed in a second direction, a first subpixel unit including a first switching element, a gate electrode of which is connected to the first gate line, one electrode of which is connected to the first data line and the other electrode of which is connected to a first subpixel electrode, and a second subpixel unit including a second switching element, a gate electrode of which is connected to the first gate line, one electrode of which is connected to the first data line and the other electrode of which is connected to a second subpixel electrode, wherein an on-resistance value of the second switching element is larger than an on-resistance value of the first switching element.

A thin-film transistor includes a gate, a first source, a second source, a first drain, a second drain, a first semiconductor layer, a second semiconductor layer, a first insulation layer, and a second insulation layer. The gate includes a first surface and a second surface that are opposite to each other. The first insulation layer is formed on the first surface and covers the first surface. The first semiconductor layer is formed on the first insulation layer. The first drain and the first source are formed on the first semiconductor layer in a spaced manner. The second insulation layer is formed on the second surface and covers the second surface. The second semiconductor layer is formed on the second insulation layer. The second drain and the second source re formed on the second semiconductor layer in a spaced manner. Also disclosed are an array substrate and a display device.

An array substrate for a liquid crystal display (LCD) device include: a substrate; a gate line formed in one direction on one surface of the substrate; a data line crossing the gate line to define a pixel area; a thin film transistor (TFT) configured at a crossing of the gate line and the data line; a pixel electrode formed at a pixel region of the substrate; an insulating film formed on the entire surface of the substrate including the pixel electrode and the TFT, including a first insulating film formed of a high temperature silicon nitride film and a second insulating film formed of a low temperature silicon nitride film, and having a contact hole having an undercut shape exposing the pixel electrode; a pixel electrode connection pattern formed within the contact hole having an undercut shape and connected with the pixel electrode and the TFT; and a plurality of common electrodes separately formed on the insulating film.

A thin film transistor array panel according to an exemplary embodiment of the present invention includes a substrate and a gate electrode disposed on the substrate. A gate insulating layer is disposed on the substrate and covers the gate electrode. A semiconductor layer is disposed on the gate insulating layer and includes a channel region, a source region, and a drain region. The source and drain regions are separated from each other by the channel region. An etch stopper is disposed on the semiconductor layer. A passivation layer is disposed on the semiconductor layer and covers the etch stopper. A source electrode and a drain electrode are disposed on the passivation layer and are respectively connected to the source region and the drain region. The passivation layer includes a first sub-passivation layer including aluminum oxide (AlO.sub.x).