METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE
First Claim
1. A method for manufacturing a semiconductor device, comprising the steps of:
- forming a gate electrode over a substrate;
forming a gate insulating layer over the gate electrode;
forming an oxide semiconductor layer over the gate insulating layer;
processing the oxide semiconductor layer by wet etching to form an island-shaped oxide semiconductor layer;
forming a conductive layer over the island-shaped oxide semiconductor layer;
processing the conductive layer by first dry etching to form a source electrode and a drain electrode; and
removing a part of the island-shaped oxide semiconductor layer by second dry etching to form a recessed portion in the island-shaped oxide semiconductor layer.
1 Assignment
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Accused Products
Abstract
An object is to establish a processing technique in manufacture of a semiconductor device in which an oxide semiconductor is used. A gate electrode is formed over a substrate, a gate insulating layer is formed over the gate electrode, an oxide semiconductor layer is formed over the gate insulating layer, the oxide semiconductor layer is processed by wet etching to form an island-shaped oxide semiconductor layer, a conductive layer is formed to cover the island-shaped oxide semiconductor layer, the conductive layer is processed by dry etching to form a source electrode, and a drain electrode and part of the island-shaped oxide semiconductor layer is removed by dry etching to form a recessed portion in the island-shaped oxide semiconductor layer.
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Citations
28 Claims
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1. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a gate electrode over a substrate; forming a gate insulating layer over the gate electrode; forming an oxide semiconductor layer over the gate insulating layer; processing the oxide semiconductor layer by wet etching to form an island-shaped oxide semiconductor layer; forming a conductive layer over the island-shaped oxide semiconductor layer; processing the conductive layer by first dry etching to form a source electrode and a drain electrode; and removing a part of the island-shaped oxide semiconductor layer by second dry etching to form a recessed portion in the island-shaped oxide semiconductor layer. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a gate electrode over a substrate; forming a gate insulating layer over the gate electrode; forming an oxide semiconductor layer over the gate insulating layer; processing the oxide semiconductor layer by wet etching to form an island-shaped oxide semiconductor layer; forming a conductive layer over the island-shaped oxide semiconductor layer; processing the conductive layer by dry etching to form a source electrode and a drain electrode; and removing a part of the island-shaped oxide semiconductor layer by the dry etching to form a recessed portion in the island-shaped oxide semiconductor layer. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a gate electrode over a substrate; forming a gate insulating layer over the gate electrode; forming a first oxide semiconductor layer over the gate insulating layer; forming a second oxide semiconductor layer over the first oxide semiconductor layer, wherein a conductivity of the second oxide semiconductor layer is higher than a conductivity of the first oxide semiconductor layer; processing the first oxide semiconductor layer and the second oxide semiconductor layer by wet etching to form a first island-shaped oxide semiconductor layer and a second island-shaped oxide semiconductor layer; forming a conductive layer over the second island-shaped oxide semiconductor layer; processing the conductive layer by first dry etching to form a source electrode and a drain electrode; and removing a part of the first island-shaped oxide semiconductor layer and a part of the second island-shaped oxide semiconductor layer by second dry etching to form a recessed portion in the first island-shaped oxide semiconductor layer. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a gate electrode over a substrate; forming a gate insulating layer over the gate electrode; forming a first oxide semiconductor layer over the gate insulating layer; forming a second oxide semiconductor layer whose conductivity is higher than a conductivity of the first oxide semiconductor layer, over the first oxide semiconductor layer; processing the first oxide semiconductor layer and the second oxide semiconductor layer by wet etching to form a first island-shaped oxide semiconductor layer and a second island-shaped oxide semiconductor layer; forming a conductive layer over the second island-shaped oxide semiconductor layer; and processing the conductive layer by dry etching to form a source electrode and a drain electrode; and removing a part of the first island-shaped oxide semiconductor layer and a part of the second island-shaped oxide semiconductor layer by the dry etching to form a recessed portion in the first island-shaped oxide semiconductor layer. - View Dependent Claims (20, 21, 22, 23, 24)
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25. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a gate electrode over a substrate; forming a gate insulating layer over the gate electrode; forming an island-shaped oxide semiconductor layer over the gate insulating layer; forming a conductive layer over the island-shaped oxide semiconductor layer; and processing the conductive layer by dry etching using a gas including chlorine and oxygen, to form a source electrode and a drain electrode; and removing part of the island-shaped oxide semiconductor layer by the dry etching to form a recessed portion in the island-shaped oxide semiconductor layer. - View Dependent Claims (26, 27, 28)
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Specification