Method for manufacturing oxide semiconductor device
First Claim
1. A method for manufacturing a semiconductor device, comprising the steps of:
- forming a gate electrode layer over an insulating surface;
forming a gate insulating layer over the gate electrode layer;
forming an oxide semiconductor layer over the gate insulating layer;
dehydrating or dehydrogenating the oxide semiconductor layer;
forming an oxide insulating layer which is in contact with part of the oxide semiconductor layer and covering a periphery and a side surface of the oxide semiconductor layer;
forming a source electrode layer and a drain electrode layer over the oxide insulating layer; and
forming a protective insulating layer which is in contact with the oxide insulating layer, the source electrode layer, the drain electrode layer, and the oxide semiconductor layer,wherein the oxide semiconductor layer is prevented from being exposed to air between the step of dehydrating or dehydrogenating the oxide semiconductor layer and the step of forming the oxide insulating layer, so as to prevent water or hydrogen contamination.
1 Assignment
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Accused Products
Abstract
An object is to provide a semiconductor device having a structure with which parasitic capacitance between wirings can be sufficiently reduced. An oxide insulating layer serving as a channel protective layer is formed over part of an oxide semiconductor layer overlapping with a gate electrode layer. In the same step as formation of the oxide insulating layer, an oxide insulating layer covering a peripheral portion of the oxide semiconductor layer is formed. The oxide insulating layer which covers the peripheral portion of the oxide semiconductor layer is provided to increase the distance between the gate electrode layer and a wiring layer formed above or in the periphery of the gate electrode layer, whereby parasitic capacitance is reduced.
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Citations
19 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 layer over an insulating surface; forming a gate insulating layer over the gate electrode layer; forming an oxide semiconductor layer over the gate insulating layer; dehydrating or dehydrogenating the oxide semiconductor layer; forming an oxide insulating layer which is in contact with part of the oxide semiconductor layer and covering a periphery and a side surface of the oxide semiconductor layer; forming a source electrode layer and a drain electrode layer over the oxide insulating layer; and forming a protective insulating layer which is in contact with the oxide insulating layer, the source electrode layer, the drain electrode layer, and the oxide semiconductor layer, wherein the oxide semiconductor layer is prevented from being exposed to air between the step of dehydrating or dehydrogenating the oxide semiconductor layer and the step of forming the oxide insulating layer, so as to prevent water or hydrogen contamination. - 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 first gate electrode layer over an insulating surface; forming a second gate electrode layer over the insulating surface; forming a gate insulating layer over the first and second gate electrode layers; forming a first oxide semiconductor layer and a second oxide semiconductor layer over the gate insulating layer; dehydrating or dehydrogenating the first and second oxide semiconductor layers; forming an oxide insulating layer which is in contact with part of the first and second oxide semiconductor layers and covering a periphery and a side surface of the first and second oxide semiconductor layers; forming a first source electrode layer and a first drain electrode layer over the first oxide insulating layer; forming a second source electrode layer and a second drain electrode layer over the second oxide insulating layer; and forming a protective insulating layer which is in contact with the oxide insulating layer, the first source electrode layer, the first drain electrode layer, and the first oxide semiconductor layer, wherein the first and second oxide semiconductor layers are prevented from being exposed to air between the step of dehydrating or dehydrogenating the first and second oxide semiconductor layers and the step of forming the oxide insulating layer, so as to prevent water or hydrogen contamination. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A method for manufacturing a semiconductor device, comprising the steps of:
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forming a gate electrode layer over an insulating surface; forming a gate insulating layer over the gate electrode layer; forming an oxide semiconductor layer over the gate insulating layer; dehydrating or dehydrogenating the oxide semiconductor layer; forming an oxide insulating layer which is in contact with an upper surface of the oxide semiconductor layer and covering a periphery and a side surface of the oxide semiconductor layer; after forming the oxide semiconductor layer, forming a source electrode layer and a drain electrode layer on and in contact with the oxide insulating layer; and after forming the source electrode layer and the drain electrode layer, forming a protective insulating layer which is in contact with the oxide insulating layer, the source electrode layer, and the drain electrode layer, wherein the oxide semiconductor layer is prevented from being exposed to air between the step of dehydrating or dehydrogenating the oxide semiconductor layer and the step of forming the oxide insulating layer, so as to prevent water or hydrogen contamination. - View Dependent Claims (15, 16, 17, 18, 19)
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Specification