X-ray imaging panel and method of manufacturing X-ray imaging panel

1. An X-ray imaging panel comprising:

a photodiode that converts scintillation light, obtained from an X-ray that passes through an object, into a signal;

a first thin-film transistor;

a first insulating film that covers at least a part of the first thin-film transistor and that has a first opening above the first thin-film transistor;

a lower electrode that is disposed below the photodiode, that covers at least a part of the first insulating film, that is formed in the first opening of the first insulating film, and that is connected to the first thin-film transistor in the first opening; and

a second insulating film that is disposed above the lower electrode and that is formed in the first opening,

wherein the photodiode covers the first opening in which the second insulating film is formed, and the photodiode is connected to the lower electrode.

2. The X-ray imaging panel according to claim 1 , wherein the photodiode includes a cathode that is connected to the lower electrode and that covers a portion of the second insulating film formed in the first opening.

3. The X-ray imaging panel according to claim 1 , wherein the first thin-film transistor includes a first semiconductor layer that contains indium, gallium, zinc, and oxygen,

wherein the first insulating film includes an organic insulating film and has a second opening that is formed above the first semiconductor layer, and

wherein the second insulating film includes an inorganic insulating film and is formed in the first opening and in the second opening.

4. The X-ray imaging panel according to claim 1 , wherein the first thin-film transistor includes a first gate electrode and a first semiconductor layer,

wherein the X-ray imaging panel further comprises a second thin-film transistor that includes a second gate electrode formed in the same layer as the first gate electrode, a third gate electrode formed in the same layer as the lower electrode, and a second semiconductor layer formed between the second gate electrode and the third gate electrode in a vertical direction and in the same layer as the first semiconductor layer,

wherein the first insulating film has a third opening that is formed above the second semiconductor layer and a fourth opening that is formed above the second gate electrode,

wherein the third gate electrode is formed across the third opening and the fourth opening and is connected to the second gate electrode in the fourth opening, and

wherein the second insulating film is disposed in the third opening and in the fourth opening above the third gate electrode.

5. A method of manufacturing an X-ray imaging panel that includes a photodiode for converting scintillation light, obtained from an X-ray that passes through an object, into a signal, the method comprising:

forming a first thin-film transistor on a substrate;

forming a first insulating film such that the first insulating film covers at least a part of the first thin-film transistor;

forming a first opening in the first insulating film above the first thin-film transistor;

forming a lower electrode in the first opening such that the lower electrode covers at least a part of the first insulating film and is connected to the first thin-film transistor in the first opening;

forming a second insulating film in the first opening above the lower electrode; and

forming a photodiode such that the photodiode covers the first opening in which the second insulating film is formed, and the photodiode is connected to the lower electrode.

6. The method according to claim 5 , wherein forming the second insulating film comprises:

depositing an insulating member such that the insulating member covers the lower electrode and forms a recessed portion in the first opening;

disposing positive photoresist on the insulating member;

exposing the positive photoresist to light and removing the positive photoresist that is exposed to the light; and

removing a portion of the insulating member other than a portion at which the positive photoresist remains by etching the insulating member.

7. The method according to claim 5 , wherein forming the first thin-film transistor includes forming a first semiconductor layer that contains indium, gallium, zinc, and oxygen,

wherein forming the first insulating film includes depositing the first insulating film by using an organic material,

wherein the method further comprises forming a second opening in the first insulating film above the first semiconductor layer when the first opening is formed,

wherein forming the second insulating film includes depositing the second insulating film in the first opening and in the second opening by using an inorganic material.

8. The method according to claim 5 , wherein forming the first thin-film transistor comprises:

forming a first gate electrode on the substrate; and

forming a first semiconductor layer above the first gate electrode,

wherein the method further comprises forming a second thin-film transistor that includes a second gate electrode and a third gate electrode,

wherein forming the second thin-film transistor comprises: forming the second gate electrode in the same layer as the first gate electrode; forming a second semiconductor layer above the second gate electrode and in the same layer as the first semiconductor layer; and forming the third gate electrode above the second semiconductor layer and in the same layer as the lower electrode,

wherein forming the first insulating film comprises forming a third opening in the first insulating film above the second semiconductor layer and forming a fourth opening in the first insulating film above the second gate electrode,

wherein forming the third gate electrode comprises forming the third gate electrode across the third opening and the fourth opening such that the second gate electrode and the third gate electrode are connected to each other in the fourth opening, and

wherein forming the second insulating film comprises forming the second insulating film in the third opening and in the fourth opening above the third gate electrode.