Semiconductor device and manufacturing method thereof
First Claim
1. A semiconductor device comprising:
- an oxide semiconductor layer;
a first buffer layer and a second buffer layer in contact with the oxide semiconductor layer;
a source electrode layer and a drain electrode layer overlapping with the oxide semiconductor layer with the first buffer layer and the second buffer layer provided therebetween, respectively;
a gate insulating layer in contact with the oxide semiconductor layer; and
a gate electrode layer overlapping with the oxide semiconductor layer with the gate insulating layer provided therebetween,wherein the gate electrode layer has a stacked-layer structure,wherein one layer of the stacked-layer structure, whose surface is in contact with the gate insulating layer, is a first metal oxide containing nitrogen, andwherein each of the first buffer layer and the second buffer layer is a second metal oxide containing nitrogen.
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Accused Products
Abstract
A semiconductor device having a novel structure or a method for manufacturing the semiconductor device is provided. For example, the reliability of a transistor which is driven at high voltage or large current is improved. For improvement of the reliability of the transistor, a buffer layer is provided between a drain electrode layer (or a source electrode layer) and an oxide semiconductor layer such that the end portion of the buffer layer is beyond the side surface of the drain electrode layer (or the source electrode layer) when seen in a cross section, whereby the buffer layer can relieve the concentration of electric field. The buffer layer is a single layer or a stacked layer including a plurality of layers, and includes, for example, an In—Ga—Zn—O film containing nitrogen, an In—Sn—O film containing nitrogen, an In—Sn—O film containing SiOx, or the like.
174 Citations
41 Claims
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1. A semiconductor device comprising:
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an oxide semiconductor layer; a first buffer layer and a second buffer layer in contact with the oxide semiconductor layer; a source electrode layer and a drain electrode layer overlapping with the oxide semiconductor layer with the first buffer layer and the second buffer layer provided therebetween, respectively; a gate insulating layer in contact with the oxide semiconductor layer; and a gate electrode layer overlapping with the oxide semiconductor layer with the gate insulating layer provided therebetween, wherein the gate electrode layer has a stacked-layer structure, wherein one layer of the stacked-layer structure, whose surface is in contact with the gate insulating layer, is a first metal oxide containing nitrogen, and wherein each of the first buffer layer and the second buffer layer is a second metal oxide containing nitrogen. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 28)
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10. A semiconductor device comprising:
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an oxide semiconductor layer; a first buffer layer and a second buffer layer in contact with the oxide semiconductor layer; a source electrode layer and a drain electrode layer overlapping with the oxide semiconductor layer with the first buffer layer and the second buffer layer provided therebetween, respectively; a gate insulating layer in contact with the oxide semiconductor layer; and a gate electrode layer overlapping with the oxide semiconductor layer with the gate insulating layer provided therebetween, wherein the gate electrode layer has a stacked-layer structure, wherein one layer of the stacked-layer structure, whose surface is in contact with the gate insulating layer, is a first metal oxide containing nitrogen, wherein each of the first buffer layer and the second buffer layer is a second metal oxide containing nitrogen, and wherein the surface is a top surface. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 29)
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19. A semiconductor device comprising:
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an oxide semiconductor layer; a first buffer layer and a second buffer layer in contact with the oxide semiconductor layer; a source electrode layer and a drain electrode layer overlapping with the oxide semiconductor layer with the first buffer layer and the second buffer layer provided therebetween, respectively; a gate insulating layer in contact with the oxide semiconductor layer; and a gate electrode layer overlapping with the oxide semiconductor layer with the gate insulating layer provided therebetween, wherein the gate electrode layer has a stacked-layer structure, wherein one layer of the stacked-layer structure, whose surface is in contact with the gate insulating layer, is a first metal oxide containing nitrogen, wherein each of the first buffer layer and the second buffer layer is a second metal oxide containing nitrogen, wherein the surface is a bottom surface. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 30)
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31. A semiconductor device comprising:
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an oxide semiconductor layer; a gate electrode layer overlapping with the oxide semiconductor layer; and a gate insulating layer between the oxide semiconductor layer and the gate electrode layer, wherein the gate electrode layer comprises a first layer and a second layer, wherein the first layer comprises a metal element, oxygen, and nitrogen, wherein the second layer comprises copper, and wherein the first layer, the second layer, and the oxide semiconductor layer overlap with one another. - View Dependent Claims (32, 33, 34, 35)
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36. A semiconductor device comprising:
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an oxide semiconductor layer; a source electrode layer electrically connected to the oxide semiconductor layer; a drain electrode layer electrically connected to the oxide semiconductor layer; a first buffer layer between the oxide semiconductor layer and the source electrode layer; a second buffer layer between the oxide semiconductor layer and the drain electrode layer; a gate electrode layer overlapping with the oxide semiconductor layer; and a gate insulating layer between the oxide semiconductor layer and the gate electrode layer, wherein each of the first buffer layer and the second buffer layer comprises a metal element, oxygen, and nitrogen, and wherein the gate electrode layer comprises a metal element, oxygen, and nitrogen. - View Dependent Claims (37, 38, 39, 40, 41)
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Specification