Method for manufacturing semiconductor device
First Claim
1. A method for manufacturing a semiconductor device, the method comprising the steps of:
- forming a gate electrode layer over a substrate having an insulating surface;
forming a gate insulating layer over the gate electrode layer;
forming an oxide semiconductor layer over the gate insulating layer;
forming a metal film over and in contact with the oxide semiconductor layer;
etching the metal film to form an exposed region in the oxide semiconductor layer and to form a source electrode layer and a drain electrode layer over and in contact with the oxide semiconductor layer;
performing plasma treatment on the exposed region in the presence of a gas containing an oxygen element; and
forming an oxide insulating film over and in contact with the oxide semiconductor layer, the source electrode layer, and the drain electrode layer,wherein the etching is performed so that the exposed region of the oxide semiconductor layer has a smaller thickness than a region of the oxide semiconductor layer which is covered with the source electrode layer or the drain electrode layer.
1 Assignment
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Accused Products
Abstract
Disclosed is a method to manufacture a thin film transistor having an oxide semiconductor as a channel formation region. The method includes; forming an oxide semiconductor layer over a gate insulating layer; forming a source and drain electrode layers over and in contact with the oxide semiconductor layer so that at least portion of the oxide semiconductor layer is exposed; and forming an oxide insulating film over and in contact with the oxide semiconductor layer. The exposed portion of the oxide semiconductor may be exposed to a gas containing oxygen in the presence of plasma before the formation of the oxide insulating film. The method allows oxygen to be diffused into the oxide semiconductor layer, which contributes to the excellent characteristics of the thin film transistor.
141 Citations
35 Claims
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1. A method for manufacturing a semiconductor device, the method comprising the steps of:
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forming a gate electrode layer over a substrate having an insulating surface; forming a gate insulating layer over the gate electrode layer; forming an oxide semiconductor layer over the gate insulating layer; forming a metal film over and in contact with the oxide semiconductor layer; etching the metal film to form an exposed region in the oxide semiconductor layer and to form a source electrode layer and a drain electrode layer over and in contact with the oxide semiconductor layer; performing plasma treatment on the exposed region in the presence of a gas containing an oxygen element; and forming an oxide insulating film over and in contact with the oxide semiconductor layer, the source electrode layer, and the drain electrode layer, wherein the etching is performed so that the exposed region of the oxide semiconductor layer has a smaller thickness than a region of the oxide semiconductor layer which is covered with the source electrode layer or the drain electrode layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for manufacturing a semiconductor device, the method comprising the steps of:
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forming a gate electrode layer over a substrate having an insulating surface; forming a gate insulating layer over the gate electrode layer; forming an oxide semiconductor layer over the gate insulating layer; forming a metal film over and in contact with the oxide semiconductor layer; etching the metal film to form an exposed region in the oxide semiconductor layer and to form a source electrode layer and a drain electrode layer over and in contact with the oxide semiconductor layer; introducing the substrate into a chamber; introducing a gas containing an oxygen element into the chamber with the substrate left in the chamber; generating plasma in the presence of the gas in the chamber with the substrate left in the chamber; and forming an oxide insulating film over and in contact with the oxide semiconductor layer, the source electrode layer, and the drain electrode layer in the chamber, wherein the etching is performed so that the exposed region of the oxide semiconductor layer has a smaller thickness than a region of the oxide semiconductor layer which is covered with the source electrode layer or the drain electrode layer. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method for manufacturing a semiconductor device, the method comprising the steps of:
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forming a gate electrode layer over a substrate having an insulating surface; forming a gate insulating layer over the gate electrode layer; forming an oxide semiconductor layer over the gate insulating layer; forming a metal film over and in contact with the oxide semiconductor layer; etching the metal film to form an exposed region in the oxide semiconductor layer and to form a source electrode layer and a drain electrode layer over and in contact with the oxide semiconductor layer; introducing the substrate into a chamber; evacuating the chamber with the substrate left in the chamber; introducing a nitrogen gas to the chamber with the substrate left in the chamber; heating the substrate in the chamber with the substrate left in the chamber; introducing a gas containing an oxygen element into the chamber with the substrate left in the chamber; introducing plasma into the chamber in the presence of the gas with the substrate left in the chamber; and forming an oxide insulating film over and in contact with the oxide semiconductor layer, the source electrode layer, and the drain electrode layer in the chamber, wherein the etching is performed so that the exposed region of the oxide semiconductor layer has a smaller thickness than a region of the oxide semiconductor layer which is covered with the source electrode layer or the drain electrode layer. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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26. A method for manufacturing a semiconductor device, the method comprising the steps of:
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forming a gate electrode layer over a substrate having an insulating surface; forming a gate insulating layer over the gate electrode layer; forming an oxide semiconductor layer over the gate insulating layer; forming a source electrode layer and a drain electrode layer over the oxide semiconductor layer; and performing plasma treatment on the oxide semiconductor layer in the presence of a gas containing an oxygen element, wherein a thickness of the oxide semiconductor layer in a region between the source electrode layer and the drain electrode layer is smaller than a thickness of the oxide semiconductor layer in a region covered with the source electrode layer or the drain electrode layer. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34, 35)
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Specification