Method for the integration of monolithic thin film radiation detector systems

Patent metadata

Field	Value
Publication number	US-11296140-B2
Application number	US-201816605534-A
Country	US
Kind code	B2
Filing date	Apr 13, 2018
Priority date	Apr 18, 2017
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

A thin film radiation detection device includes a photosensitive p-n diode, a polysilicon thin film transistor (TFT), a radiation detection layer, and a substrate. The photosensitive p-n diode and the TFT are formed on the substrate. The radiation detection layer is formed above the substrate and receives multiple radiations. The photosensitive p-n diode receives a conversion output signal from the radiation detection layer and generates a detector signal. The TFT generates an amplified signal based on the detector signal.

First claim

What is claimed is:

1. A radiation detection device, comprising:
a first portion of a first polysilicon layer formed on a substrate, wherein the first portion of the first polysilicon layer is a cathode;
an n-type layer formed on the first portion of the first polysilicon layer;
a p-type layer formed on the n-type layer;
a metal layer formed on the p-type layer, wherein the metal layer is an anode, and wherein the n-type and p-type layers, the cathode, and the anode form a photosensitive diode;
a second polysilicon layer formed on the substrate, wherein the second polysilicon layer is an active polysilicon island;

a second portion of the first polysilicon layer formed above the second polysilicon layer, wherein the second portion of the first polysilicon layer is a gate electrode;
a first layer formed on a first region of the second polysilicon layer, wherein the first layer is a source electrode;
a second layer formed on a second region of the second polysilicon layer, wherein the second layer is a drain electrode, and wherein the active polysilicon island, and the gate, source, and drain electrodes form a transistor; and
a radiation detection layer formed above the substrate, wherein the radiation detection layer is configured to receive a plurality of radiations and generate a conversion output signal, wherein the photosensitive diode is configured to receive the conversion output signal and generate a detector signal, and wherein the transistor is configured to receive the detector signal and generate an amplified signal.

2. The radiation detection device according to claim 1 , wherein the substrate includes at least one of polyethylene naphthalate, polyethylene terephthalate, a flexible aluminum foil, a flexible stainless steel sheet, and flexible glass.

3. The radiation detection device of claim 1 , wherein the n-type layer includes cadmium sulfide.

4. The radiation detection device of claim 1 , wherein the p-type layer includes cadmium telluride.

5. The radiation detection device of claim 1 , wherein the radiation detection layer includes at least one of a scintillation layer and a neutron conversion layer.

6. The radiation detection device of claim 1 , wherein the transistor is a thin film transistor.

7. A method for fabricating a radiation detection device, the method comprising:
forming a first portion of a first polysilicon layer on a substrate, wherein the first portion of the first polysilicon layer is a cathode;
forming an n-type layer on the first portion of the first polysilicon layer;

forming a p-type layer on the n-type layer;
forming a metal layer on the p-type layer, wherein the metal layer is an anode, and wherein the p-type and n-type layers, the anode, and the cathode form a photosensitive diode;
forming a second polysilicon layer on the substrate, wherein the second polysilicon layer is an active polysilicon island;
forming a second portion of the first polysilicon layer above the second polysilicon layer, wherein the second portion of the first polysilicon layer is a gate electrode;
forming a first layer on a first region of the second polysilicon layer, wherein the first layer is a source electrode;
forming a second layer on a second region of the second polysilicon layer, wherein the second layer is a drain electrode, and wherein the active polysilicon island, and the gate, source, and drain electrodes form a transistor; and
forming a radiation detection layer above the substrate, wherein the radiation detection layer receives a plurality of radiations and generates a conversion output signal, wherein the photosensitive diode receives the conversion output signal and generates a detector signal, and wherein the transistor receives the detector signal and generates an amplified signal.

8. The method of claim 7 , wherein the substrate includes at least one of polyethylene naphthalate, polyethylene terephthalate, a flexible aluminum foil, a flexible stainless steel sheet, and flexible glass.

9. The method of claim 7 , wherein the n-type layer includes cadmium sulfide.

10. The method of claim 7 , wherein the p-type layer includes cadmium telluride.

11. The method of claim 7 , wherein the radiation detection layer includes at least one of a scintillation layer and a neutron conversion layer.

12. The method of claim 7 , wherein the transistor is a thin film transistor.

13. The radiation detection device of claim 2 , wherein the n-type layer includes cadmium sulfide.

14. The radiation detection device of claim 13 , wherein the p-type layer includes cadmium telluride.

15. The radiation detection device of claim 14 , wherein the radiation detection layer includes at least one of a scintillation layer and a neutron conversion layer.

16. The radiation detection device of claim 15 , wherein the transistor is a thin film transistor.

17. The method of claim 8 , wherein the n-type layer includes cadmium sulfide.

18. The method of claim 17 , wherein the p-type layer includes cadmium telluride.

19. The method of claim 18 , wherein the radiation detection layer includes at least one of a scintillation layer and a neutron conversion layer.

20. The method of claim 19 , wherein the transistor is a thin film transistor.

Assignees

• Univ Texas
• Nanoholdings Llc

Inventors

• Mejia-Silva Jesus I
• Quevedo-Lopez Manuel
• Gnade Bruce E
• Avila Avendano Carlos Hugo
• Pradhan Bhabendra K

Classifications

• H10D30/6745

  Polycrystalline or microcrystalline silicon · CPC title

• H10D30/6731

  Top-gate only TFTs · CPC title

• H10F77/1698

  the metallic or insulating substrates being flexible · CPC title

• H10F77/1696

  the films including Group II-VI materials, e.g. CdTe or CdS · CPC title

• H10F39/80377

  characterised by the channel of the transistor, e.g. channel having a doping gradient · CPC title