Simplified method of making active matrix liquid crystal display
AssigneeIndustrial Technology Research Institute
InventorBiing-Seng Wu
Life of this patent
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Abstract
An inverted staggered (bottom gate) thin film transistor (TFT) for active matrix liquid crystal display is processed with three masks. The first mask is used to pattern a metal film on a glass substrate as the gate of the TFT, the scan line of the TFT array, and a portion of the data line of the TFT array. The second mask is used to form a TFT mesa with a gate dielectric layer, an a-Si layer as channel, and a heavily-doped n+s-Si layer for contacting the source and the drain of the TFT. A third mask is used to pattern the transparent conductive indium-tin oxide film as the pixel electrode, the source/drain electrodes of the TFT, and the interconnections of the data line.
Claims7
A three mask method of fabricating an inverted staggered thin film transistor of an inverted staggered structure for active matrix crystal display systems with a matrix of picture elements, each thin film transistor having a gate, a source, and a drain, comprising the steps of:
- depositing a metal film on a transparent substrate;
- patterning said metal film as said gate electrode of said thin film transistor, as scan lines, and as data lines using a first mask;
- successively depositing an insulating layer, an amorphous semiconductor layer, and a heavily doped amorphous semiconductor layer over said transparent substrate;
- simultaneously patterning said insulating layer, said amorphous semiconductor layer, and said heavily doped amorphous semiconductor layer using a second mask to form a mesa;
- depositing a transparent conducting layer over said mesa;
- and
- patterning said transparent conducting layer using a third mask to form electrodes of picture elements, and crossover connections of said data lines at cross-points with said scan lines.
Dependencies are inferred from the claim text.