A plurality of address wiring layers and a plurality of data wiring layers are arranged to cross each other at a right angle. TFTs are respectively arranged at the intersections between the address wiring layers and the data wiring layers. The gate electrode of each TFT is connected to an address wiring layer for each row. The drain electrode of each TFT is connected to a data wiring layer for each column. Display electrodes are respectively arranged in the regions defined by the address wiring layers and the data wiring layers, and are connected to the source electrodes of the TFTs arranged in the respective regions. The data wiring layers and the source and drain electrodes of the TFTs each comprise the first layer serving as an ohmic barrier layer for a semiconductor layer, the second layer forming of a conductive material and serving as a main signal wiring layer, and the third layer serving as a battery reaction preventing layer.
A liquid crystal display has wires made of aluminum alloy layer, and two molybdenum-tungsten alloy layers MoW located on/under the aluminum alloy layer, respectively. To form a wire, the first molybdenum-tungsten alloy layer, the aluminum alloy layer, and the second molybdenum-tungsten alloy layer are sequentially deposited. The molybdenum-tungsten alloy layer has different etch rates for one etchant, depending on the deposition temperature and tungsten content ratio. Particularly, since the molybdenum-tungsten alloy layer has an etch rate similar to that of an aluminum layer and aluminum alloy layer for an aluminum etchant CH.sub.3 COOH/HNO.sub.3 /H.sub.3 PO.sub.4 /H.sub.2 O. Therefore, the first molybdenum-tungsten alloy layer having a lower etch rate than that of the aluminum layer or the aluminum alloy layer, and the second molybdenum-tungsten alloy layer having a higher etch rate than that of the aluminum layer or the aluminum alloy layer may be formed by adjusting deposition temperature and tungsten content ratio. Accordingly, the wires have a gradually sloped taper angle.
A multiplex control active matrix display screen including a first transparent substrate supporting an array of electrodes controlled by an array of transistors. Each transistor has two control gates. The second gates are interconnected along an addressing row or column. The rows and columns are interconnected in groups of N. The transistors of a column or row are then controlled by multiplexed three control signals.
A color display device such as an active-matrix type liquid crystal display apparatus has a first substrate having pixel electrodes arranged in the form of the matrix, switching elements associated with respective pixel electrodes and color filters aligned with the respective pixel electrodes. The first substrate is composed of a laminate structure including, superposed in the mentioned sequence, a first layer having the switching elements, a second layer having the color filters, a third layer including a planarization film which fills convexities presented by the switching elements and the color filters, and a fourth layer having the pixel electrodes aligned with the color filter. The display device also has a second substrate including a counter electrode and adjoined to the first substrate leaving a predetermined gap left therebetween. A liquid crystal is charged in the gap between the first and second substrates.
First and second gate insulating films, a semiconductor layer made of a-Si(i), and an etching stopper layer are formed to cover a gate electrode on a glass substrate. A drain electrode side contact layer and a source electrode side contact layer are made out of a-Si(n.sup.+) in such a manner to be cut off on the etching stopper layer. A disconnection preventing a-Si(n.sup.+) wire is formed below a source wire in its longitudinal direction, and atop of which a pixel electrode is formed. Since the disconnection preventing a-Si(n.sup.+) wire and source electrode side contact layer are spaced apart, static-induced characteristics deterioration of TFT and the point and line defects during the substrate fabrication sequence can be eliminated and the non-defective ratio of the display device can be improved drastically.
A color display device such as an active-matrix type liquid crystal display apparatus has a first substrate having pixel electrodes arranged in the form of the matrix, switching elements associated with respective pixel electrodes and color filters aligned with the respective pixel electrodes. The first substrate is composed of a laminate structure including, superposed in the mentioned sequence, a first layer having the switching elements, a second layer having the color filters, a third layer including a planarization film which fills convexities presented by the switching elements and the color filters, and a fourth layer having the pixel electrodes aligned with the color filter. The display device also has a second substrate including a counter electrode and adjoined to the first substrate leaving a predetermined gap left therebetween. A liquid crystal is charged in the gap between the first and second substrates.
