Methods for forming an amorphous silicon film in display devices

• US 7,955,890 B2
• Filed: 06/17/2009
• Issued: 06/07/2011
• Est. Priority Date: 06/24/2008
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Chen, Jriyan Jerry, Choi, Soo Young, Won, Tae Kyung, Yim, Dong-Kil
• Primary Examiner(s): LEBENTRITT, MICHAEL
• Application Number:
  US12/486,435
• Publication Number:
  US 20090315030A1
• Time in Patent Office: 720 Days
• Field of Search: 438/30, 438 71- 74, 438 93- 97, 438485-488, 257/E21.009, 257/51, 257/101, 257/133, 257/351, 257411-413, 257/25.007, 257/29.083, 257293-294, 257/31.039, 257 47- 48
• US Class Current: 438/93
• CPC Class Codes: G02F 1/13312 Circuits comprising photodetectors for purposes other than feedback
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 2201/58 Arrangements comprising a monitoring photodetector
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0421 by interrupting or reflecting a light beam, e.g. optical touch-screen
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02576 N-type
• CPC Class Codes: H01L 21/02579 P-type
• CPC Class Codes: H01L 21/02592 amorphous
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1446 in a repetitive configuration
• CPC Class Codes: H01L 31/022466 made of transparent conductive layers, e.g. TCO, ITO layers
• CPC Class Codes: H01L 31/03762 including only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/153 formed in, or on, a common substrate
• CPC Class Codes: H01L 31/202 including only elements of Group IV of the Periodic Table
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells

Abstract

Embodiments of the present invention relate to methods for depositing an amorphous film that may be suitable for using in a NIP photodiode in display applications. In one embodiment, the method includes providing a substrate into a deposition chamber, supplying a gas mixture having a hydrogen gas to silane gas ratio by volume greater than 4 into the deposition chamber, maintaining a pressure of the gas mixture at greater than about 1 Torr in the deposition chamber, and forming an amorphous silicon film on the substrate in the presence of the gas mixture, wherein the amorphous silicon film is configured to be an intrinsic-type layer in a photodiode sensor.

Claims

1. A method of depositing an amorphous layer, comprising:

providing a substrate into a deposition chamber;

supplying a gas mixture having a hydrogen gas to silane gas ratio by volume greater than 4 into the deposition chamber;

maintaining a pressure of the gas mixture at greater than about 1 Torr in the deposition chamber; and

forming an amorphous silicon film on the substrate in the presence of the gas mixture, wherein the amorphous silicon film is configured to be an intrinsic-type layer in a photodiode sensor.

2. The method of claim 1, further comprising:

performing a hydrogen treatment on the substrate process prior to forming the amorphous silicon film.

3. The method of claim 1, wherein supplying the gas mixture further comprises:

controlling the ratio by volume of hydrogen gas to the silane gas at between about 4;

1 and about 15;

1.

4. The method of claim 1, wherein supplying the gas mixture further comprises:

controlling the ratio by volume of hydrogen gas to the silane gas at about 12.5;

1.

5. The method of claim 1, wherein the pressure is maintained at between about 1 Torr and about 20 Torr.

6. The method of claim 1, wherein the pressure is maintained at about 2.5 Torr.

7. A display device comprising a touch panel having the photodiode sensor comprising the amorphous silicon layer deposited by the method of claim 1.

8. The display device of claim 7, comprising:

a thin film transistor formed on the substrate and integreated with the photodiode sensor.

9. An amorphous-based photodiode sensor, comprising:

a metal electrode layer disposed on a substrate;

an n-type amorphous silicon layer disposed on the metal electrode layer;

an intrinsic type amorphous silicon layer disposed on the n-type amorphous silicon layer, wherein the intrinsic type amorphous silicon layer is deposited from a gas mixture having a hydrogen gas to silane gas ratio by volume greater than 4; and

a p-type amorphous silicon layer disposed on the intrinsic type amorphous silicon layer, wherein the n-type, intrinsic type and p-type amorphous silicon layers form a photodiode sensor on the substrate.

10. The amorphous-based photodiode sensor of claim 9, wherein the metal electrode is selected from a group consisting of Al, Ag, Ti, Cr, Au, Cu, Pt, alloys thereof and combinations thereof.

11. The amorphous-based photodiode sensor of claim 9, wherein the n-type amorphous silicon layer has a thickness between about 30 Å

and about 300 Å

.

12. The amorphous-based photodiode sensor of claim 9, wherein the intrinsic-type amorphous silicon layer has a thickness between about 500 Å

and about 10,000 Å

.

13. The amorphous-based photodiode sensor of claim 9, wherein the p-type amorphous silicon layer has a thickness between about 100 Å

and about 400 Å

.

14. The amorphous-based photodiode sensor of claim 9, wherein the intrinsic type amorphous silicon layer is formed at a process pressure maintained greater than 1 Torr.

15. The amorphous-based photodiode sensor of claim 9, wherein a hydrogen treatment process is performed prior to forming each n-type, intrinsic type and p-type amorphous silicon layers on the substrate.

16. A display device comprising:

a touch panel having the photodiode sensor of claim 9.

17. A method of forming an amorphous-based photodiode sensor, comprising:

forming a n-type amorphous silicon layer on a substrate;

forming an intrinsic type amorphous silicon layer on the substrate; and

forming a p-type amorphous silicon layer on the substrate, wherein the n-type amorphous silicon layer, intrinsic type amorphous silicon layer and the p-type amorphous silicon layer are laterally spaced and sequentially formed on the substrate, and the n-type, intrinsic type and p-type amorphous silicon layers form a photodiode sensor on the substrate;

wherein the intrinsic type amorphous silicon layer is deposited from a gas mixture having a hydrogen gas to silane gas ratio greater than 4.

18. The method of claim 17, further comprising:

forming a thin film transistor adjacent to the photodiode sensor on the substrate.

19. The method of claim 17, wherein the intrinsic type amorphous silicon is formed at a process pressure greater than 1 Torr.