Thin-film transistor, display unit, and electronic apparatus
View Patent ↗Provided is a thin-film transistor that includes: a substrate; a first barrier film formed on the substrate; a second barrier film formed in a selective region on the first barrier film, and having a barrier property against hydrogen; an oxide semiconductor layer including a first part formed on the second barrier film and a second part formed on the first barrier film, in which the first part functions as an active layer, and the second part has lower electrical resistance than the first part; a gate electrode formed on the first part of the oxide semiconductor layer with a gate insulating film therebetween; and a source electrode or drain electrode electrically connected to the second part of the oxide semiconductor layer. The first barrier film has a barrier property against an impurity from the substrate and a property of chemically reducing the oxide semiconductor layer.
1. A thin-film transistor comprising:
a substrate;
a first barrier film formed on the substrate;
a second barrier film formed in a selective region on the first barrier film, and having a barrier property against hydrogen;
an oxide semiconductor layer including a first part formed on the second barrier film and a second part formed on the first barrier film, the first part functioning as an active layer, and the second part having lower electrical resistance than the first part;
a gate electrode formed on the first part of the oxide semiconductor layer with a gate insulating film therebetween; and
a source electrode or drain electrode electrically connected to the second part of the oxide semiconductor layer,
the first barrier film having a barrier property against an impurity from the substrate and a property of chemically reducing the oxide semiconductor layer.
2. The thin-film transistor according to claim 1 , wherein
the first barrier film contains one or both of silicon nitride and silicon oxynitride, and
the second barrier film is a single-layered film or a stacked film that contains one or more of oxide silicon, silicon oxynitride, aluminum oxide, and titanium oxide.
3. The thin-film transistor according to claim 1 , wherein the substrate is made of a flexible resin material.
4. The thin-film transistor according to claim 1 , wherein the second part of the oxide semiconductor layer is formed in contact with the first barrier film.
5. The thin-film transistor according to claim 1 , wherein the gate electrode and the gate insulating film are patterned into same shape as one another.
6. The thin-film transistor according to claim 1 , wherein the second part of the oxide semiconductor layer is utilized to form a retention capacity.
7. The thin-film transistor according to claim 1 , wherein the source electrode or drain electrode is provided to oppose a portion of the second part of the oxide semiconductor layer.
8. A display unit comprising:
a display region provided with a plurality of pixels, each of the pixels being provided with a thin-film transistor, each of the thin-film transistors comprising:
a substrate;
a first barrier film formed on the substrate;
a second barrier film formed in a selective region on the first barrier film, and having a barrier property against hydrogen;
an oxide semiconductor layer including a first part formed on the second barrier film and a second part formed on the first barrier film, the first part functioning as an active layer, and the second part having lower electrical resistance than the first part;
a gate electrode formed on the first part of the oxide semiconductor layer with a gate insulating film therebetween; and
a source electrode or drain electrode electrically connected to the second part of the oxide semiconductor layer, the first barrier film having a barrier property against an impurity from the substrate and a property of chemically reducing the oxide semiconductor layer.
9. The display unit according to claim 8 , wherein the display unit is an organic electroluminescence display unit.
10. An electronic apparatus comprising:
a display unit, the display unit including a display region, the display region being provided with a plurality of pixels arranged in a matrix, each of the pixels being provided with a thin-film transistor, each of the thin-film transistors comprising:
a substrate;
a first barrier film formed on the substrate;
a second barrier film formed in a selective region on the first barrier film, and having a barrier property against hydrogen;
an oxide semiconductor layer including a first part formed on the second barrier film and a second part formed on the first barrier film, the first part functioning as an active layer, and the second part having lower electrical resistance than the first part;
a gate electrode formed on the first part of the oxide semiconductor layer with a gate insulating film therebetween; and
a source electrode or drain electrode electrically connected to the second part of the oxide semiconductor layer, the first barrier film having a barrier property against an impurity from the substrate and a property of chemically reducing the oxide semiconductor layer.