US5392245A
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US
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Redundancy elements using thin film transistors (TFTs)
Assignee: Micron Technology Inc
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Filing: 1993-08-13
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Granted: 1995-02-21
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Expires: 2013-08-13
Abstract
Abstract An embodiment of the present invention describes a redundancy repair circuit fabricated in a Static Random Access Memory (SRAM) semiconductor device, with the redundancy repair circuit comprising: a plurality of thin film transistors (TFTs); a programming pad connecting to serially connected control gates of the plurality of TFTs; the plurality of TFTs having their individual source/drain terminals connecting between substitution logic and an address multiplexer. The redundancy repair circuit is operated by a method for shifting the threshold voltages of the TFTs using a programming pad connected serially to the control gates of a plurality of TFTs; the plurality of TFTs having their individual output terminals connecting between substitution logic and an address multiplexer; selecting an individual TFT by the address multiplexer; shorting at least one of the output terminals of the selected TFT to approximately a 5 V potential; shorting the output terminals of the remaining (non-selected) TFTs to approximately a 0 V potential; and applying a programming signal to the programming pad, the programming signal is sufficient to cause the threshold voltage of the selected TFT to shift approximately 1 V by injecting electrons into the TFT's gate dielectric region while not effecting the threshold voltage of each individual said non-selected TFTs.
Inventors
- 👤 Monte Manning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:38
CPC Classifications
G; G11; G11C; G11C29/00; G11C29/70; G11C29/78; G11C29/785; G11C29/789; G11C16/00; G11C16/02; G11C16/04; G11C16/0466
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
131 words
A method for shifting the threshold voltages of thin film transistors (TFTs) in a redundancy repair circuit fabricated on a supporting substrate, said method comprising: using a programming pad connected serially to the control gates of a plurality of TFTs; selecting individual TFTs; shorting one of the output terminals of each selected TFT to a first potential; shorting one of the output terminals of each remaining (non-selected) TFTs to a second potential, therefore producing an approximate 5 V offset between said first and second potentials; and applying a programming signal to said programming pad, said programming signal is sufficient to cause the threshold voltage of each selected TFTs to shift by injecting charge into the TFT's gate insulation region while not affecting the threshold voltage of each individual said non-selected TFT.
Claim 2
Independent Claim
131 words
A method for shifting the threshold voltages of thin film transistors (TFTs) in a redundancy repair circuit fabricated on a supporting substrate, said method comprising: using a programming pad connected serially to the control gates of a plurality of TFTs; selecting individual TFTs; shorting one of the output terminals of each selected TFT to a first potential; shorting one of the output terminals of each remaining (non-selected) TFTs to a second potential, therefore producing an approximate 5 V offset between said first and second potentials; and applying a programming signal to said programming pad, said programming signal is sufficient to cause the threshold voltage of each selected TFTs to shift by injecting charge into the TFT's gate insulation region while not affecting the threshold voltage of each individual said non-selected TFT.
Claim 3
Dependent Claim
13 words
The method of claim 1, wherein said programming signal comprises a voltage source.
Claim 4
Dependent Claim
13 words
The method of claim 1, wherein said programming signal comprises a current source.
Claim 5
Dependent Claim
14 words
The method of claim 1, wherein said output terminals comprise source and drain terminals.
Claim 6
Independent Claim
146 words
A method for shifting the threshold voltages of thin film transistors (TFTs) in a redundancy repair circuit fabricated in a semiconductor device, said method comprising: using a programming pad connected serially to the control gates of a plurality of TFTs; selecting individual TFTs; shorting at least one of the output terminals of each selected TFT to a first potential that is approximately at 5 V; shorting the output terminals of the remaining (nonselected) TFTs to a second potential that is approximately 0 V and thereby producing an approximate 5 V offset between said first and second potentials; and applying a programming signal to said programming pad, said programming signal is sufficient to cause the threshold voltage of each selected TFT to shift approximately 1 V by injecting electrons into the TFT's gate dielectric region while not effecting the individual threshold voltage of each said non-selected TFTs.
Claim 7
Independent Claim
146 words
A method for shifting the threshold voltages of thin film transistors (TFTs) in a redundancy repair circuit fabricated in a semiconductor device, said method comprising: using a programming pad connected serially to the control gates of a plurality of TFTs; selecting individual TFTs; shorting at least one of the output terminals of each selected TFT to a first potential that is approximately at 5 V; shorting the output terminals of the remaining (nonselected) TFTs to a second potential that is approximately 0 V and thereby producing an approximate 5 V offset between said first and second potentials; and applying a programming signal to said programming pad, said programming signal is sufficient to cause the threshold voltage of each selected TFT to shift approximately 1 V by injecting electrons into the TFT's gate dielectric region while not effecting the individual threshold voltage of each said non-selected TFTs.
Claim 8
Dependent Claim
15 words
The method of claim 5, wherein said first potential comprises the semiconductor device's operating potential.
Claim 9
Dependent Claim
15 words
The method of claim 5, wherein said second potential comprises the semiconductor device's ground potential.
Claim 10
Dependent Claim
13 words
The method of claim 5, wherein said programming signal comprises a voltage source.
Claim 11
Dependent Claim
13 words
The method of claim 5, wherein said programming signal comprises a current source.
Claim 12
Dependent Claim
16 words
The method of claim 5, wherein said method is performed after said semiconductor device is packaged.
Claim 13
Dependent Claim
26 words
The method of claim 5, wherein said TFT's gate dielectric is a dielectric selected from the group comprising oxide, nitride, oxide/nitride, oxide/nitride/oxide and any combination thereof.
Claim 14
Dependent Claim
14 words
The method of claim 5, wherein said output terminals comprise source and drain terminals.
Claim 15
Independent Claim
131 words
A method for shifting the threshold voltages of thin film transistors (TFTs) fabricated in a redundancy repair circuit of a Static Random Access Memory (SRAM) semiconductor device, said method comprising: using a programming pad connected serially to the control gates of a plurality of TFTs; selecting an individual TFT; shorting at least one of the output terminals of said selected TFT to approximately a 5 V potential; shorting the output terminals of the remaining (nonselected) TFTs to approximately a 0 V potential; and applying a programming signal to said programming pad, said programming signal is sufficient to cause the threshold voltage of said selected TFT to shift approximately 1 V by injecting electrons into the TFT's gate dielectric region while not effecting the threshold voltage of each individual said non-selected TFTs.
Claim 16
Independent Claim
131 words
A method for shifting the threshold voltages of thin film transistors (TFTs) fabricated in a redundancy repair circuit of a Static Random Access Memory (SRAM) semiconductor device, said method comprising: using a programming pad connected serially to the control gates of a plurality of TFTs; selecting an individual TFT; shorting at least one of the output terminals of said selected TFT to approximately a 5 V potential; shorting the output terminals of the remaining (nonselected) TFTs to approximately a 0 V potential; and applying a programming signal to said programming pad, said programming signal is sufficient to cause the threshold voltage of said selected TFT to shift approximately 1 V by injecting electrons into the TFT's gate dielectric region while not effecting the threshold voltage of each individual said non-selected TFTs.
Claim 17
Dependent Claim
15 words
The method of claim 13, wherein said first potential comprises the semiconductor device's operating potential.
Claim 18
Dependent Claim
26 words
The method of claim 13, wherein said programming signal has a potential of approximately -30 V and is applied for a period of approximately 6 seconds.
Claim 19
Dependent Claim
21 words
The method of claim 13, wherein said programming signal comprises a current source of approximately -300 pA for approximately 6 seconds.
Claim 20
Dependent Claim
16 words
The method of claim 13, wherein said method is performed after said semiconductor device is packaged.
Claim 21
Dependent Claim
26 words
The method of claim 13, wherein said TFT's gate dielectric is a dielectric selected from the group comprising oxide, nitride, oxide/nitride, oxide/nitride/oxide and any combination thereof.
Claim 22
Dependent Claim
14 words
The method of claim 13, wherein said output terminals comprise source and drain terminals.
Claim 23
Dependent Claim
36 words
A redundancy repair circuit fabricated on a supporting substrate, said redundancy repair circuit comprising: a plurality of thin film transistors (TFTs); and a programming pad connecting to serially connected control gates of said plurality of TFTs.
Claim 24
Dependent Claim
36 words
A redundancy repair circuit fabricated on a supporting substrate, said redundancy repair circuit comprising: a plurality of thin film transistors (TFTs); and a programming pad connecting to serially connected control gates of said plurality of TFTs.
Claim 25
Dependent Claim
15 words
The redundancy repair circuit of claim 20, wherein said supporting substrate comprises a silicon wafer.
Claim 26
Dependent Claim
27 words
The redundancy repair circuit claim 20, wherein the TFT's gate dielectric is a dielectric selected from the group comprising oxide, nitride, oxide/nitride, oxide/nitride/oxide and any combination thereof.
Claim 27
Dependent Claim
36 words
A redundancy repair circuit fabricated in a semiconductor device, said redundancy repair circuit comprising: a plurality of thin film transistors (TFTs); and a programming pad connecting to serially connected control gates of said plurality of TFTs.
Claim 28
Dependent Claim
36 words
A redundancy repair circuit fabricated in a semiconductor device, said redundancy repair circuit comprising: a plurality of thin film transistors (TFTs); and a programming pad connecting to serially connected control gates of said plurality of TFTs.
Claim 29
Dependent Claim
15 words
The redundancy repair circuit of claim 23, wherein said supporting substrate comprises a silicon wafer.
Claim 30
Dependent Claim
13 words
The redundancy repair circuit of claim 23, wherein said TFTs are p-channel TFTs.
Claim 31
Dependent Claim
13 words
The redundancy repair circuit of claim 23, wherein said TFTs are n-channel TFTs.
Claim 32
Dependent Claim
27 words
The redundancy repair circuit claim 23, wherein the TFT's gate dielectric is a dielectric selected from the group comprising oxide, nitride, oxide/nitride, oxide/nitride/oxide and any combination thereof.
Claim 33
Dependent Claim
41 words
A redundancy repair circuit fabricated in a Static Random Access Memory (SRAM) semiconductor device, said redundancy repair circuit comprising: a plurality of thin film transistors (TFTs); and a programming pad connecting to serially connected control gates of said plurality of TFTs.
Claim 34
Dependent Claim
41 words
A redundancy repair circuit fabricated in a Static Random Access Memory (SRAM) semiconductor device, said redundancy repair circuit comprising: a plurality of thin film transistors (TFTs); and a programming pad connecting to serially connected control gates of said plurality of TFTs.
Claim 35
Dependent Claim
15 words
The redundancy repair circuit of claim 28, wherein said supporting substrate comprises a silicon wafer.
Claim 36
Dependent Claim
13 words
The redundancy repair circuit of claim 28, wherein said TFTs are p-channel TFTs.
Claim 37
Dependent Claim
13 words
The redundancy repair circuit of claim 28, wherein said TFTs are n-channel TFTs.
Claim 38
Dependent Claim
27 words
The redundancy repair circuit claim 28, wherein the TFT's gate dielectric is a dielectric selected from the group comprising oxide, nitride, oxide/nitride, oxide/nitride/oxide and any combination thereof.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-02-20 | 1998-08-22 | 1999-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-20 | 2002-08-22 | 2003-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-20 | 2006-08-22 | 2007-02-21 | $7700.00 | Window Closed / Lapsed |