Transistor, liquid crystal display device, and manufacturing method thereof
First Claim
1. A method for manufacturing a liquid crystal display device, comprising the steps of:
- forming a gate electrode and a wiring over a substrate by a first photolithography step;
forming a gate insulating layer over the gate electrode;
forming a semiconductor layer over the gate insulating layer;
forming a source electrode and a drain electrode over the semiconductor layer by a second photolithography step;
forming an insulating layer over the source electrode and the drain electrode;
forming a contact hole by selectively removing a first part of the insulating layer overlapping with the drain electrode and removing a second part of the insulating layer, part of the semiconductor layer, and part of the gate insulating layer, by a third photolithography step; and
forming a pixel electrode over the insulating layer by a fourth photolithography step,wherein the second part of the insulating layer, the part of the semiconductor layer, and the part of the gate insulating layer each overlap with the wiring.
1 Assignment
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Accused Products
Abstract
Photolithography and etching steps for forming an island-shaped semiconductor layer are omitted, and a liquid crystal display device is manufactured with four photolithography steps: a step of forming a gate electrode (including a wiring formed using the same layer as the gate electrode), a step of forming source and drain electrodes (including a wiring formed using the same layer as the source and drain electrodes), a step of forming a contact hole (including the removal of an insulating layer and the like in a region other than the contact hole), and a step of forming a pixel electrode (including a wiring formed using the same layer as the pixel electrode). By the reduction in the number of photolithography steps, a liquid crystal display device can be provided at low cost and high productivity. Formation of a parasitic channel is prevented by an improvement in shape and potential of a wiring.
145 Citations
19 Claims
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1. A method for manufacturing a liquid crystal display device, comprising the steps of:
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forming a gate electrode and a wiring over a substrate by a first photolithography step; forming a gate insulating layer over the gate electrode; forming a semiconductor layer over the gate insulating layer; forming a source electrode and a drain electrode over the semiconductor layer by a second photolithography step; forming an insulating layer over the source electrode and the drain electrode; forming a contact hole by selectively removing a first part of the insulating layer overlapping with the drain electrode and removing a second part of the insulating layer, part of the semiconductor layer, and part of the gate insulating layer, by a third photolithography step; and forming a pixel electrode over the insulating layer by a fourth photolithography step, wherein the second part of the insulating layer, the part of the semiconductor layer, and the part of the gate insulating layer each overlap with the wiring. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for manufacturing a liquid crystal display device, comprising the steps of:
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forming a gate electrode, a first wiring and a capacitor wiring over a substrate by a first photolithography step; forming a gate insulating layer over the gate electrode; forming a semiconductor layer over the gate insulating layer; forming a source electrode, a drain electrode and a second wiring over the semiconductor layer by a second photolithography step; and forming a pixel electrode over the source electrode, the drain electrode and the second wiring by a third photolithography step, wherein the first wiring is electrically connected to the gate electrode, wherein the second wiring is electrically connected to the source electrode, wherein the pixel electrode is electrically connected to the drain electrode, wherein the semiconductor layer overlaps with the first wiring, the second wiring, the pixel electrode, and the capacitor wiring, and wherein the semiconductor layer overlaps with an entirety of the pixel electrode. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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Specification