X-ray detector including oxide semiconductor transistor

• US 8,963,096 B2
• Filed: 12/17/2010
• Issued: 02/24/2015
• Est. Priority Date: 03/30/2010
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Sun-il, Park, Jae-chul, Kim, Sang-wook, Kim, Chang-jung
• Primary Examiner(s): Bryant, Casey
• Application Number:
  US12/926,921
• Publication Number:
  US 20110240869A1
• Time in Patent Office: 1,530 Days
• Field of Search: 250/370.08, 250/370.09, 250/370.14
• US Class Current: 250/370.09
• CPC Class Codes: G01T 1/24 with semiconductor detectors
• CPC Class Codes: H01L 31/085 the device being sensitive to very short wavelength, e.g. X-ray, Gamma-rays

Abstract

Example embodiments are directed an X-ray detector including an oxide semiconductor transistor. The X-ray detector including the oxide semiconductor transistor includes an oxide semiconductor transistor and a signal storage capacitor in parallel to each other on a substrate. The oxide semiconductor transistor includes a channel formed of an oxide semiconductor material, and a photoconductor. A pixel electrode and a common electrode are formed on opposite surfaces of the photoconductor. The channel includes ZnO, or a compound including ZnO and at least one selected from a group consisting of gallium (Ga), indium (In), hafnium (Hf), and tin (Sn).

Claims

1. An X-ray detector, comprising:

a substrate;

an oxide semiconductor transistor on the substrate, the oxide semiconductor transistor including a source electrode, a gate electrode, a drain electrode, and a channel of an oxide semiconductor material;

a signal storage capacitor on the substrate, the signal storage capacitor including an upper electrode and a lower electrode;

a pixel electrode on the upper electrode and connected to the upper electrode;

a first diffusion-prevention layer on the pixel electrode;

a photoconductor on the first diffusion-prevention layer;

a common electrode on the photoconductor; and

a signal processor connected to the drain electrode;

wherein the oxide semiconductor transistor and the signal storage capacitor are parallel to each other on the substrate,

wherein the first diffusion-prevention layer is of a conductive polymer or a conductive oxide semiconductor, and

wherein the first diffusion-prevention layer prevents diffusion of constituents of the photoconductor into the pixel electrode.

2. The X-ray detector of claim 1, further comprising:

a first insulating layer on the gate electrode and the lower electrode;

the source electrode, the drain electrode, the channel, and the upper electrode on the first insulating layer; and

a connection wiring connecting the source electrode and the upper electrode.

3. The X-ray detector of claim 1, further comprising:

a second insulating layer on the oxide semiconductor transistor and the signal storage capacitor; and

a contact hole through the second insulating layer, the contact hole connecting the pixel electrode to the signal storage capacitor.

4. The X-ray detector of claim 1, wherein the channel comprises ZnO, or a compound including ZnO and at least one selected from a group consisting of gallium (Ga), indium (In), hafnium (Hf), and aluminum (Al).

5. The X-ray detector of claim 1, wherein the channel is an oxide channel comprising SnO₂, or a compound including SnO₂ and at least one selected from a group consisting of gallium (Ga), indium (In), hafnium (Hf), and aluminum (Al).

6. The X-ray detector of claim 1, wherein the photoconductor includes at least one selected from a group consisting of amorphous selenium (a-Se), HgI₂, PbI₂, CdTe, CdZnTe;

PbO, TlBr, and amorphous silicon (a-Si).

7. The X-ray detector of claim 1, wherein the first diffusion-prevention layer has a thickness of about 0.1 μ

m to about 100 μ

m.

8. The X-ray detector of claim 1, wherein the conductive oxide semiconductor comprises a compound including ZnO, or ZnO and at least one selected from a group consisting of gallium (Ga), indium (In), hafnium (Hf), and tin (Sn).

9. The X-ray detector of claim 1, further comprising a second diffusion-prevention layer between the common electrode and the photoconductor.

10. The X-ray detector of claim 9, wherein the second diffusion-prevention layer has a thickness of about 100 A°

to about 500 A°

.

11. An X-ray detector, comprising:

a substrate;

an oxide semiconductor transistor on the substrate, the oxide semiconductor transistor including a source electrode, a gate electrode, a drain electrode, and a channel of an oxide semiconductor material;

a signal storage capacitor on the substrate, the signal storage capacitor including an upper electrode and a lower electrode;

a pixel electrode on the upper electrode and connected to the upper electrode;

a first diffusion-prevention layer on the pixel electrode;

a photoconductor on and in contact with the first diffusion-prevention layer;

a common electrode on the photoconductor; and

a signal processor connected to the drain electrode;

wherein the oxide semiconductor transistor and the signal storage capacitor are parallel to each other on the substrate,

wherein the first diffusion-prevention layer is of a conductive polymer or a conductive oxide semiconductor, and

wherein the first diffusion-prevention layer prevents diffusion of constituents of the photoconductor into the pixel electrode.

12. The X-ray detector of claim 11, further comprising:

a first insulating layer on the gate electrode;

wherein the source electrode, the drain electrode, and the channel are on the first insulating layer.

13. The X-ray detector of claim 11, further comprising:

a first insulating layer on the lower electrode;

wherein the upper electrode is on the first insulating layer.

14. The X-ray detector of claim 11, further comprising:

a first insulating layer on the gate electrode and the lower electrode;

wherein the source electrode, the drain electrode, the channel, and the upper electrode are on the first insulating layer.

15. An X-ray detector, comprising:

a substrate;

an oxide semiconductor transistor on the substrate, the oxide semiconductor transistor including a source electrode, a gate electrode, a drain electrode, and a channel of an oxide semiconductor material;

a signal storage capacitor on the substrate, the signal storage capacitor including an upper electrode and a lower electrode;

a pixel electrode on the upper electrode and connected to the upper electrode;

a first diffusion-prevention layer on the pixel electrode;

a photoconductor on the first diffusion-prevention layer;

a second diffusion-prevention layer on and in contact with the photoconductor;

a common electrode on the second diffusion-prevention layer; and

a signal processor connected to the drain electrode;

wherein the oxide semiconductor transistor and the signal storage capacitor are parallel to each other on the substrate,

wherein the first diffusion-prevention layer is of a conductive polymer or a conductive oxide semiconductor, and

wherein the first diffusion-prevention layer prevents diffusion of constituents of the photoconductor into the pixel electrode.

16. The X-ray detector of claim 15, further comprising:

a first insulating layer on the gate electrode;

wherein the source electrode, the drain electrode, and the channel are on the first insulating layer.

17. The X-ray detector of claim 15, further comprising:

a first insulating layer on the lower electrode;

wherein the upper electrode is on the first insulating layer.

18. The X-ray detector of claim 15, further comprising:

a first insulating layer on the gate electrode and the lower electrode;

wherein the source electrode, the drain electrode, the channel, and the upper electrode are on the first insulating layer.

19. The X-ray detector of claim 15, wherein the photoconductor is on and in contact with the first diffusion-prevention layer.