Semiconductor device with indium or zinc layer in contact with oxide semiconductor layer and method for manufacturing the semiconductor device
First Claim
1. A semiconductor device comprising:
- a substrate having an insulating surface;
a gate electrode layer over the substrate having the insulating surface;
a gate insulating layer over the gate electrode layer;
an oxide semiconductor layer over the gate insulating layer;
a first metal layer on and in contact with the oxide semiconductor layer; and
a source electrode layer and a drain electrode layer over the first metal layer,wherein the source electrode layer and the drain electrode layer are formed with a stack of layers, andwherein the first metal layer is an indium layer or an indium-alloy layer.
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Accused Products
Abstract
An object is to reduce contact resistance between an oxide semiconductor layer and source and drain electrode layers electrically connected to the oxide semiconductor layer in a thin film transistor including the oxide semiconductor layer. The source and drain electrode layers have a stacked structure of two or more layers. In this stack of layers, a layer in contact with the oxide semiconductor layer is a thin indium layer or a thin indium-alloy layer. Note that the oxide semiconductor layer contains indium. A second layer or second and any of subsequent layers in the source and drain electrode layers are formed using an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, an alloy containing any of these elements as a component, an alloy containing any of these elements in combination, or the like.
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Citations
26 Claims
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1. A semiconductor device comprising:
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a substrate having an insulating surface; a gate electrode layer over the substrate having the insulating surface; a gate insulating layer over the gate electrode layer; an oxide semiconductor layer over the gate insulating layer; a first metal layer on and in contact with the oxide semiconductor layer; and a source electrode layer and a drain electrode layer over the first metal layer, wherein the source electrode layer and the drain electrode layer are formed with a stack of layers, and wherein the first metal layer is an indium layer or an indium-alloy layer. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A semiconductor device comprising:
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a substrate having an insulating surface; a gate electrode layer over the substrate having the insulating surface; a gate insulating layer over the gate electrode layer; an oxide semiconductor layer over the gate insulating layer; a first metal layer on and in contact with the oxide semiconductor layer; a source electrode layer and a drain electrode layer over the first metal layer, wherein the source electrode layer and the drain electrode layer are formed with a stack of layers, wherein the first metal layer is a zinc layer or a zinc-alloy 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 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 first metal layer on and in contact with the oxide semiconductor layer; forming a stack of metal conductive layers over the first metal layer; and etching the first metal layer and the stack of metal conductive layers, so that a source electrode layer and a drain electrode layer are formed, wherein the first metal layer is an indium layer or an indium-alloy layer. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. A method for manufacturing a semiconductor device, 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 first metal layer on and in contact with the oxide semiconductor layer; forming a stack of metal conductive layers over the first metal layer; and etching the first metal layer and the stack of metal conductive layers, so that a source electrode layer and a drain electrode layer are formed, wherein the first metal layer is a zinc layer or a zinc-alloy layer. - View Dependent Claims (21, 22, 23, 24, 25, 26)
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Specification