US 2019/0293980 A1Published application

Thin film transistor substrate, display device, and method of manufacturing thin film transistor substrate

AssigneeMitsubishi Electric Corporation

InventorsKazunori INOUE, Koji ODA, Takafumi HASHIGUCHI, Takeshi KUBOTA

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Abstract

An opening insulation film covers a substrate and is in contact with a side surface of a gate electrode. The opening insulation film is provided with a first opening portion having a side surface on the gate electrode. A gate insulation film made of an oxide insulator is on the gate electrode and the opening insulation film. A semiconductor channel film made of an oxide semiconductor is on the gate insulation film and is encompassed by the first opening portion. Source and drain electrodes are on the semiconductor channel film. A source upper-layer electrode and a drain upper-layer electrode both made of an oxide are provided at least on upper surfaces of the source electrode and the drain electrode, respectively. An interlayer insulation film made of an oxide has a portion provided on the source upper-layer electrode and the drain upper-layer electrode and is in contact the semiconductor channel film.

Claims16

Dependent claims

A thin film transistor substrate including a thin film transistor having a layered structure in which a first conductive layer, a first insulation layer, a second insulation layer made of an oxide insulator different from a material of the first insulation layer, an oxide semiconductor layer, a second conductive layer, a third conductive layer made of an oxide, and a third insulation layer made of an oxide are disposed on a substrate, the thin film transistor substrate comprising:

a gate electrode provided on the substrate and having a side surface, the gate electrode being included in the first conductive layer;
an opening insulation film covering the substrate and in contact with the side surface of the gate electrode, the opening insulation film being provided with a first opening portion having a side surface on the gate electrode, the opening insulation film being included in the first insulation layer;
a gate insulation film provided on the gate electrode and the opening insulation film, the gate insulation film being included in the second insulation layer;
a semiconductor channel film provided on the gate insulation film and encompassed by the first opening portion of the opening insulation film as seen in plan view, the semiconductor channel film being included in the oxide semiconductor layer;
a source electrode and a drain electrode provided on the semiconductor channel film and included in the second conductive layer;
a source upper-layer electrode provided at least on an upper surface of the source electrode and included in the third conductive layer;
a drain upper-layer electrode provided at least on an upper surface of the drain electrode and included in the third conductive layer;
and
an interlayer insulation film having a portion provided on the source upper-layer electrode and the drain upper-layer electrode and in contact with the semiconductor channel film, the interlayer insulation film being included in the third insulation layer.

6 more elements

A method of manufacturing a thin film transistor substrate including a thin film transistor disposed on a substrate, the method comprising the steps of:

(A) forming a gate electrode having a side surface from a first conductive layer deposited on a substrate;
(B) forming an opening insulation film from a first insulation layer deposited so as to cover the substrate, the opening insulation film being in contact with the side surface of the gate electrode, the opening insulation film being provided with a first opening portion having a side surface on the gate electrode;
(C) depositing a second insulation layer made of an oxide insulator different from a material of the first insulation layer on the gate electrode and the opening insulation film to form a gate insulation film;
(D) patterning a laminate comprised of an oxide semiconductor layer and a second conductive layer deposited in sequential order on the gate insulation film to form a semiconductor channel film from the oxide semiconductor layer, the semiconductor channel film being encompassed by the first opening portion of the opening insulation film as seen in plan view;
and
(E) depositing a third conductive layer made of an oxide and patterning a laminate comprised of the third conductive layer and the second conductive layer into two spaced portions on an upper surface of the semiconductor channel film to form a source electrode and a drain electrode from the second conductive layer on the upper surface of the semiconductor channel film and to form a source upper-layer electrode and a drain upper-layer electrode from the third conductive layer on the source electrode and the drain electrode, respectively.

3 more elements

Dependencies are inferred from the claim text.