PROCESS TO MAKE METAL OXIDE THIN FILM TRANSISTOR ARRAY WITH ETCH STOPPING LAYER
First Claim
1. A thin film transistor formation method, comprising:
- depositing and patterning a gate electrode over a substrate;
depositing a gate dielectric layer over the gate electrode;
depositing a semiconductive active layer over the gate dielectric layer, the semiconductive active layer comprising oxygen, nitrogen, and one or more elements selected from the group consisting of zinc, indium, cadmium, gallium, and tin;
depositing an etch stop layer over the active layer;
forming a first mask over the etch stop layer;
etching the etch stop layer to form a patterned etch stop layer;
removing the first mask to expose the patterned etch stop layer;
depositing a metal layer over the patterned etch stop layer;
forming a second mask over the metal layer;
etching the metal layer to define a source electrode and a drain electrode;
removing the second mask;
etching the active layer using the source electrode and the drain electrode as a mask; and
depositing a passivation layer over the source electrode and the drain electrode.
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Accused Products
Abstract
The present invention generally relates to thin film transistors (TFTs) and methods of making TFTs. The active channel of the TFT may comprise one or more metals selected from the group consisting of zinc, gallium, tin, indium, and cadmium. The active channel may also comprise nitrogen and oxygen. To protect the active channel during source-drain electrode patterning, an etch stop layer may be deposited over the active layer. The etch stop layer prevents the active channel from being exposed to the plasma used to define the source and drain electrodes. The etch stop layer and the source and drain electrodes may be used as a mask when wet etching the active material layer that is used for the active channel.
146 Citations
20 Claims
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1. A thin film transistor formation method, comprising:
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depositing and patterning a gate electrode over a substrate; depositing a gate dielectric layer over the gate electrode; depositing a semiconductive active layer over the gate dielectric layer, the semiconductive active layer comprising oxygen, nitrogen, and one or more elements selected from the group consisting of zinc, indium, cadmium, gallium, and tin; depositing an etch stop layer over the active layer; forming a first mask over the etch stop layer; etching the etch stop layer to form a patterned etch stop layer; removing the first mask to expose the patterned etch stop layer; depositing a metal layer over the patterned etch stop layer; forming a second mask over the metal layer; etching the metal layer to define a source electrode and a drain electrode; removing the second mask; etching the active layer using the source electrode and the drain electrode as a mask; and depositing a passivation layer over the source electrode and the drain electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method, comprising:
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depositing a semiconductor layer over a substrate, the semiconductor layer comprising oxygen, nitrogen, and one or more elements selected from the group consisting of zinc, gallium, indium, cadmium, and tin; depositing an etch stop layer over the semiconductor layer; forming a first mask over the etch stop layer; patterning the etch stop layer to form a patterned etch stop layer; removing the first mask; depositing a metal layer over the patterned etch stop layer and the semiconductor layer; forming a second mask over the metal layer; etching the metal layer to form a patterned metal layer; removing the second mask; and etching at least a portion of the semiconductor layer while using the patterned metal layer and the patterned etch stop layer as masks. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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18. A thin film transistor, comprising:
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a gate electrode disposed over a substrate; a gate dielectric layer disposed over the gate electrode; a semiconductor layer disposed over the gate dielectric layer, the semiconductor layer comprising oxygen, nitrogen, and one or more elements selected from the group consisting of zinc, gallium, indium, cadmium, and tin; a source electrode; a drain electrode; and an etch stop layer disposed over the semiconductor layer and between the source electrode and the drain electrode. - View Dependent Claims (19, 20)
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Specification