Patent US5508227A successfully refreshed from Google Patents.
US5508227A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma ion implantation hydrogenation process utilizing voltage pulse applied to substrate
Assignee: Northeastern University
•
Filing: 1994-06-08
•
Granted: 1996-04-16
•
Expires: 2014-06-08
Abstract
Abstract A method of hydrogenating a thin film semiconductor wafer and an apparatus for performing the method. In one embodiment the method comprises the steps applying a pulsed potential having a predetermined amplitude, a predetermined repetition rate and a predetermined pulse duration to the thin film semiconductor wafer while exposing the thin film semiconductor wafer to a hydrogen plasma. The method is especially applicable to the formation of thin film transistors in flat display panels.
Inventors
- 👤 Chung Chan
- 👤 Shu Qin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:10
CPC Classifications
C; C23; C23C; C23C8/00; C23C8/06; C23C8/36; H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32412; H10; H10P; H10P95/00; H10P95/94
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
109 words
A method of hydrogenating a TFT wafer comprising the steps of: placing a TFT wafer in a vacuum chamber; permitting a volume of hydrogen gas to enter said vacuum chamber to a pressure; ionizing at least a portion of said volume of hydrogen gas to form a hydrogen ion plasma; confining said hydrogen ion plasma at a substantially uniform density to a region adjacent said TFT wafer; applying a negative pulse potential to said TFT wafer, said pulse potential having a constant amplitude, a repetition rate and a pulse duration; and exposing said TFT wafer with said pulsed potential to said hydrogen ion plasma for an amount of time.
Claim 2
Independent Claim
109 words
A method of hydrogenating a TFT wafer comprising the steps of: placing a TFT wafer in a vacuum chamber; permitting a volume of hydrogen gas to enter said vacuum chamber to a pressure; ionizing at least a portion of said volume of hydrogen gas to form a hydrogen ion plasma; confining said hydrogen ion plasma at a substantially uniform density to a region adjacent said TFT wafer; applying a negative pulse potential to said TFT wafer, said pulse potential having a constant amplitude, a repetition rate and a pulse duration; and exposing said TFT wafer with said pulsed potential to said hydrogen ion plasma for an amount of time.
Claim 3
Dependent Claim
28 words
The method of hydrogenating a TFT wafer of claim 1 wherein said hydrogen plasma is formed using a microwave source operating between about 600 W and 730 W.
Claim 4
Dependent Claim
25 words
The method of hydrogenating a TFT wafer of claim 2 wherein said hydrogen plasma is formed using a microwave source operating at about 730 W.
Claim 5
Dependent Claim
22 words
The method of hydrogenating a TFT wafer of claim 1 wherein said pulse duration is between about 1 μsec and 50 μsec.
Claim 6
Dependent Claim
22 words
The method of hydrogenating a TFT wafer of claim 4 wherein said pulse duration is between about 5 μsec and 10 μsec.
Claim 7
Dependent Claim
23 words
The method of hydrogenating a TFT wafer of claim 1 wherein said pulse repetition rate is between about 0.5 kHz and 20 kHz.
Claim 8
Dependent Claim
23 words
The method of hydrogenating a TFT wafer of claim 6 wherein said pulse repetition rate is between about 5 kHz and 10 kHz.
Claim 9
Dependent Claim
23 words
The method of hydrogenating a TFT wafer of claim 1 wherein said pulse potential amplitude is between about -1 kV and -20 kV.
Claim 10
Dependent Claim
23 words
The method of hydrogenating a TFT wafer of claim 8 wherein said pulse potential amplitude is between about -6 kV and -7 kV.
Claim 11
Dependent Claim
18 words
The method of hydrogenating a TFT wafer of claim 1 wherein said time is less than 1 hour.
Claim 12
Dependent Claim
20 words
The method of hydrogenating a TFT wafer of claim 10 wherein said time is between 10 minutes and 30 minutes.
References Cited (Backward Citations)
US4764394A
Cited
US4891118A
Cited
US5250444A
Cited
WO1993018201A1
Cited
US5281546A
Cited
US5354381A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-16 | 1999-10-16 | 2000-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-16 | 2003-10-16 | 2004-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-16 | 2007-10-16 | 2008-04-16 | $7700.00 | Window Closed / Lapsed |