US5566111A
Expired / Lapsed
US
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Method for programming a nonvolatile memory
Assignee: FIDELIX Co Ltd
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Filing: 1995-10-13
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Granted: 1996-10-15
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Expires: 2015-10-13
Abstract
Abstract A method for programming a nonvolatile memory cell having a control gate, a floating gate, a drain, a source, and a channel region disposed between the drain and source, the method includes the steps of applying a first voltage to the control gate to form an inversion layer in the channel region, the first voltage being varied to program at least two threshold levels of the memory cell, applying a second voltage to the drain and a third voltage to the source, the second voltage being greater than the third voltage, monitoring a current flowing between the drain and the source during the programming of the at least two threshold levels, and terminating any one of the first voltage, the second voltage, and the third voltage when the monitored current reaches a preset reference current to thereby stop the programming of the at least two threshold levels.
Inventors
- 👤 Woong-Lim Choi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:18
CPC Classifications
G; G11; G11C; G11C16/00; G11C16/02; G11C16/06; G11C16/34; G11C16/3436; G11C16/3468; G11C16/3486; G11C11/00; G11C11/56; G11C11/5621; G11C11/5628; G11C11/5635; G11C16/10; G11C2211/00; G11C2211/56; G11C2211/562; G11C2211/5624
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
147 words
A method for programming a nonvolatile memory cell having a control gate, a floating gate, a drain, a source, and a channel region disposed between the drain and source, the method comprising the steps of: applying a first voltage to the control gate to form an inversion layer in the channel region, the first voltage being varied to program at least two threshold levels of the memory cell; applying a second voltage to the drain and a third voltage to the source, the second voltage being greater than the third voltage; monitoring a current flowing between the drain and the source during the programming of the at least two threshold levels; and terminating any one of the first voltage, the second voltage, and the third voltage when the monitored current reaches a preset reference current to thereby stop the programming of the at least two threshold levels.
Claim 2
Independent Claim
147 words
A method for programming a nonvolatile memory cell having a control gate, a floating gate, a drain, a source, and a channel region disposed between the drain and source, the method comprising the steps of: applying a first voltage to the control gate to form an inversion layer in the channel region, the first voltage being varied to program at least two threshold levels of the memory cell; applying a second voltage to the drain and a third voltage to the source, the second voltage being greater than the third voltage; monitoring a current flowing between the drain and the source during the programming of the at least two threshold levels; and terminating any one of the first voltage, the second voltage, and the third voltage when the monitored current reaches a preset reference current to thereby stop the programming of the at least two threshold levels.
Claim 3
Dependent Claim
30 words
The method for programming a nonvolatile memory cell according to claim 1, wherein the reference current has a fixed value during the programming of the at least two threshold levels.
Claim 4
Independent Claim
103 words
A method for programming a nonvolatile memory cell having a control gate, a floating gate, a drain, and a source, the method comprising the steps of: applying a variable first voltage to the control gate; applying a second voltage to the drain and a third voltage to the source; monitoring a current flowing between the drain and the source during application of the first voltage to the control gate; and terminating application of any of the first voltage to the control gate, the second voltage to the drain, and the third voltage to the source when the monitored current reaches a reference current.
Claim 5
Independent Claim
103 words
A method for programming a nonvolatile memory cell having a control gate, a floating gate, a drain, and a source, the method comprising the steps of: applying a variable first voltage to the control gate; applying a second voltage to the drain and a third voltage to the source; monitoring a current flowing between the drain and the source during application of the first voltage to the control gate; and terminating application of any of the first voltage to the control gate, the second voltage to the drain, and the third voltage to the source when the monitored current reaches a reference current.
Claim 6
Dependent Claim
30 words
The method for programming a nonvolatile memory cell according to claim 3, wherein the step of monitoring the current includes the step of monitoring a voltage at the floating gate.
Claim 7
Dependent Claim
32 words
The method for programming a nonvolatile memory cell according to claim 3, wherein the step of monitoring the current includes the step of monitoring an amount of charge at the floating gate.
Claim 8
Dependent Claim
37 words
The method for programming a nonvolatile memory cell according to claim 3, wherein application of the first voltage to the control gate forms an inversion layer in a channel region disposed between the drain and the source.
Claim 9
Dependent Claim
30 words
The method for programming a nonvolatile memory cell according to claim 6, wherein the step of monitoring the current includes the step of monitoring a conductivity of the inversion layer.
Claim 10
Dependent Claim
31 words
The method for programming a nonvolatile memory cell according to claim 3, wherein the first voltage is varied linearly with respect to at least two threshold levels of the memory cell.
Claim 11
Dependent Claim
22 words
The method for programming a nonvolatile memory cell according to claim 3, wherein the second voltage is greater than the third voltage.
Claim 12
Dependent Claim
21 words
The method for programming a nonvolatile memory cell according to claim 3, wherein the reference current is a fixed reference current.
Claim 13
Independent Claim
126 words
A method for programming at least two threshold levels of a nonvolatile memory cell, the memory cell having a control gate, a floating gate, a drain, and a source, the method comprising the steps of: applying a first voltage to the control gate, the first voltage corresponding to a respective one of the at least two threshold levels; applying a second voltage to the drain and a third voltage to the source; monitoring a current flowing between the drain and the source during application of the first voltage to the control gate; and terminating application of any of the first voltage to the control gate, the second voltage to the drain, and the third voltage to the source when the monitored current reaches a reference current.
Claim 14
Independent Claim
126 words
A method for programming at least two threshold levels of a nonvolatile memory cell, the memory cell having a control gate, a floating gate, a drain, and a source, the method comprising the steps of: applying a first voltage to the control gate, the first voltage corresponding to a respective one of the at least two threshold levels; applying a second voltage to the drain and a third voltage to the source; monitoring a current flowing between the drain and the source during application of the first voltage to the control gate; and terminating application of any of the first voltage to the control gate, the second voltage to the drain, and the third voltage to the source when the monitored current reaches a reference current.
Claim 15
Dependent Claim
30 words
The method for programming a nonvolatile memory cell according to claim 11, wherein the step of monitoring the current includes the step of monitoring a voltage at the floating gate.
Claim 16
Dependent Claim
32 words
The method for programming a nonvolatile memory cell according to claim 11, wherein the step of monitoring the current includes the step of monitoring an amount of charge at the floating gate.
Claim 17
Dependent Claim
37 words
The method for programming a nonvolatile memory cell according to claim 11, wherein application of the first voltage to the control gate forms an inversion layer in a channel region disposed between the drain and the source.
Claim 18
Dependent Claim
30 words
The method for programming a nonvolatile memory cell according to claim 14, wherein the step of monitoring the current includes the step of monitoring a conductivity of the inversion layer.
Claim 19
Dependent Claim
30 words
The method for programming a nonvolatile memory cell according to claim 11, wherein the first voltage is selected according to a linear relationship with the at least two threshold levels.
Claim 20
Dependent Claim
22 words
The method for programming a nonvolatile memory cell according to claim 11, wherein the second voltage is greater than the third voltage.
Claim 21
Dependent Claim
21 words
The method for programming a nonvolatile memory cell according to claim 11, wherein the reference current is a fixed reference current.
Claim 22
Dependent Claim
21 words
The method for programming a nonvolatile memory cell according to claim 11, wherein the reference current is a fixed reference current.
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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) | 1999-10-15 | 2000-04-15 | 2000-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-15 | 2004-04-15 | 2004-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-15 | 2008-04-15 | 2008-10-15 | $7700.00 | Window Closed / Lapsed |