US5682047A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Input-output (I/O) structure with capacitively triggered thyristor for electrostatic discharge (ESD) protection
Assignee: Bell Semiconductor LLC
•
Filing: 1995-06-07
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Granted: 1997-10-28
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Expires: 2015-06-07
Abstract
Abstract An input/output structure includes a microelectronic device connected in circuit between a contact pad and a reference potential, and a thyristor device for protecting the microelectronic device from electrostatic discharge. The thyristor device includes first and second terminals connected to the contact pad and to the reference potential respectively, a PNPN thyristor structure including a first P-region, a first N-region, a second P-region and a second N-region disposed in series between the first and second terminals, and an electrode for inducing an electric field into the second P-region. The induced electric field increases the number of charge carriers in the second P-region, and enables the device to be triggered at a lower voltage applied between the first and second terminals. The electrode includes an insulated gate, and can be connected to either the first or second terminal. The gate can include a thick field oxide layer, or a thin oxide layer to further reduce the triggering voltage. A differentiator including a capacitor connected between the first terminal and the electrode and a resistor connected between the second terminal and the electrode prevents false triggering during normal operation. A metal interconnection layer includes an anode section which is connected to the N-region and to the second terminal, and a cathode section which is connected to the P-region, the first terminal and the electrode, such that the cathode section laterally surrounds the anode section.
Inventors
- 👤 Rosario Consiglio
- 👤 Yen-Hui Ku
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:13
CPC Classifications
H; H10; H10D; H10D89/00; H10D89/60; H10D89/601; H10D89/711; H10D89/713
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
114 words
An input/output structure comprising: microelectronic device connected in circuit between a contact pad and a reference potential; a thyristor device for protecting the microelectronic device from electrostatic discharge, the thyristor device including: a first terminal connected to the contact pad; a second terminal connected to the reference potential; a PNPN thyristor structure including a first P-region, a first N-region, a second P-region and a second N-region disposed in series between the first and second terminals; and an electrode for inducing an electric field into one of the first N-region and the second P-region; a capacitor connected between the first terminal and the electrode; and a resistor connected between the second terminal and the electrode.
Claim 2
Dependent Claim
114 words
An input/output structure comprising: microelectronic device connected in circuit between a contact pad and a reference potential; a thyristor device for protecting the microelectronic device from electrostatic discharge, the thyristor device including: a first terminal connected to the contact pad; a second terminal connected to the reference potential; a PNPN thyristor structure including a first P-region, a first N-region, a second P-region and a second N-region disposed in series between the first and second terminals; and an electrode for inducing an electric field into one of the first N-region and the second P-region; a capacitor connected between the first terminal and the electrode; and a resistor connected between the second terminal and the electrode.
Claim 3
Dependent Claim
32 words
An input/output structure as in claim 1, in which: the first terminal is connected in circuit to the first N-region; and the second terminal is connected in circuit to the second P-region.
Claim 4
Dependent Claim
34 words
An input/output structure as in claim 1, further comprising: a first resistor connected between the first terminal and the first N-region; and a second resistor connected between the second terminal and the second P-region.
Claim 5
Dependent Claim
15 words
An input/output structure as in claim 1, in which the electrode comprises an insulated gate.
Claim 6
Dependent Claim
28 words
An input/output structure as in claim 4, in which the insulated gate comprises: a field oxide layer; and an electrically conductive layer formed on the field oxide layer.
Claim 7
Dependent Claim
20 words
An input/output structure as in claim 5, in which the field oxide layer has a thickness of approximately 8,000 Angstroms.
Claim 8
Dependent Claim
31 words
An input/output structure as in claim 5, further comprising: a resistor connected between the microelectronic device and the contact pad, in which: the first terminal is connected to the contact pad.
Claim 9
Dependent Claim
28 words
An input/output structure as in claim 4, in which the insulated gate comprises: a thin oxide layer; and an electrically conductive layer formed on the thin oxide layer.
Claim 10
Dependent Claim
20 words
An input/output structure as in claim 8, in which the thin oxide layer has a thickness of approximately 80 Angstroms.
Claim 11
Dependent Claim
23 words
An input/output structure as in claim 1, in which the electrode is disposed for capacitively inducing an electric field into the first N-region.
Claim 12
Dependent Claim
115 words
An input/output structure comprising: a microelectronic device connected in circuit between a contact pad and a reference potential; a thyristor device for protecting the microelectronic device from electrostatic discharge, the thyristor device including: a first terminal connected to the contact pad; a second terminal connected to the reference potential; a PNPN thyristor structure including a first P-region, a first N-region, a second P-region and a second N-region disposed in series between the first and second terminals; and an electrode for inducing an electric field into one of the first N-region and the second P-region; a capacitor connected between the second terminal and the electrode; and a resistor connected between the first terminal and the electrode.
Claim 13
Dependent Claim
115 words
An input/output structure comprising: a microelectronic device connected in circuit between a contact pad and a reference potential; a thyristor device for protecting the microelectronic device from electrostatic discharge, the thyristor device including: a first terminal connected to the contact pad; a second terminal connected to the reference potential; a PNPN thyristor structure including a first P-region, a first N-region, a second P-region and a second N-region disposed in series between the first and second terminals; and an electrode for inducing an electric field into one of the first N-region and the second P-region; a capacitor connected between the second terminal and the electrode; and a resistor connected between the first terminal and the electrode.
Claim 14
Dependent Claim
129 words
An input/output structure comprising: a microelectronic device connected in circuit between a contact pad and a reference potential; a thyristor device for protecting the microelectronic device from electrostatic discharge, the thyristor device including: a first terminal connected to the contact pad; a second terminal connected to the reference potential; a PNPN thyristor structure including a first P-region, a first N-region, a second P-region and a second N-region disposed in series between the first and second terminals; and an electrode for inducing an electric field into one of the first N-region and the second P-region, the electrode being disposed for capacitively inducing an electric field into the second P-region; a capacitor connected between the first terminal and the electrode; and a resistor connected between the second terminal and the electrode.
Claim 15
Dependent Claim
129 words
An input/output structure comprising: a microelectronic device connected in circuit between a contact pad and a reference potential; a thyristor device for protecting the microelectronic device from electrostatic discharge, the thyristor device including: a first terminal connected to the contact pad; a second terminal connected to the reference potential; a PNPN thyristor structure including a first P-region, a first N-region, a second P-region and a second N-region disposed in series between the first and second terminals; and an electrode for inducing an electric field into one of the first N-region and the second P-region, the electrode being disposed for capacitively inducing an electric field into the second P-region; a capacitor connected between the first terminal and the electrode; and a resistor connected between the second terminal and the electrode.
Claim 16
Dependent Claim
19 words
An input/output structure as in claim 12, in which the capacitor has a value of approximately 7×10 -15 farads.
Claim 17
Dependent Claim
18 words
An input/output structure as in claim 12, in which the resistor has a value of approximately 60 kilo-ohms.
Claim 18
Dependent Claim
168 words
An input/output structure comprising: a semiconductor substrate; a contact pad formed on the substrate; a microelectronic device which is formed on the substrate and connected in circuit between the contact pad and a reference potential; a thyristor device for protecting the microelectronic device from electrostatic discharge, the thyristor device including: a P-well formed in the substrate; an N-well formed in the substrate laterally adjacent to the P-well; a P-region formed in the N-well; a first terminal connected to the contact pad and to the P-region; an N-region formed in the P-well; a second terminal connected to the reference potential and to the N-region; first circuit means connecting the first terminal to the N-well; second circuit means connecting the second terminal to the P-well; and an electrode formed over a portion of the P-well between the N-region and the N-well for inducing an electric field into said portion; a capacitor connected between the first terminal and the electrode; and a resistor connected between the second terminal and the electrode.
Claim 19
Dependent Claim
168 words
An input/output structure comprising: a semiconductor substrate; a contact pad formed on the substrate; a microelectronic device which is formed on the substrate and connected in circuit between the contact pad and a reference potential; a thyristor device for protecting the microelectronic device from electrostatic discharge, the thyristor device including: a P-well formed in the substrate; an N-well formed in the substrate laterally adjacent to the P-well; a P-region formed in the N-well; a first terminal connected to the contact pad and to the P-region; an N-region formed in the P-well; a second terminal connected to the reference potential and to the N-region; first circuit means connecting the first terminal to the N-well; second circuit means connecting the second terminal to the P-well; and an electrode formed over a portion of the P-well between the N-region and the N-well for inducing an electric field into said portion; a capacitor connected between the first terminal and the electrode; and a resistor connected between the second terminal and the electrode.
Claim 20
Dependent Claim
26 words
An input/output structure as in claim 15, in which: the first circuit means comprises a first resistor; and the second circuit means comprises a second resistor.
Claim 21
Dependent Claim
34 words
An input/output structure as in claim 16, in which: the first resistor comprises a P + -region formed in the P-well; and the second resistor comprises an N + -region formed in the N-well.
Claim 22
Dependent Claim
39 words
An input/output structure as in claim 15, further comprising an N + -region formed at an interface between the P-well and the N-well, in which: said portion of the P-well is between the N-region and the N + -region.
Claim 23
Dependent Claim
24 words
An input/output structure as in claim 18, in which: the N-region is an N + -region; and the P-region is a P + -region.
Claim 24
Dependent Claim
15 words
An input/output structure as in claim 15, in which the electrode comprises an insulated gate.
Claim 25
Dependent Claim
28 words
An input/output structure as in claim 20, in which the insulated gate comprises: a field oxide layer; and an electrically conductive layer formed on the field oxide layer.
Claim 26
Dependent Claim
31 words
An input/output structure as in claim 21, further comprising: a resistor connected between the microelectronic device and the contact pad, in which: the first terminal is connected to the contact pad.
Claim 27
Dependent Claim
20 words
An input/output structure as in claim 21, in which the field oxide layer has a thickness of approximately 8,000 Angstroms.
Claim 28
Dependent Claim
28 words
An input/output structure as in claim 20, in which the insulated gate comprises: a thin oxide layer; and an electrically conductive layer formed on the thin oxide layer.
Claim 29
Dependent Claim
20 words
An input/output structure as in claim 24, in which the thin oxide layer has a thickness of approximately 80 Angstroms.
Claim 30
Dependent Claim
19 words
An input/output structure as in claim 15, in which the capacitor has a value of approximately 7×10 -15 farads.
Claim 31
Dependent Claim
18 words
An input/output structure as in claim 15, in which the resistor has a value of approximately 60 kilo-ohms.
Claim 32
Dependent Claim
50 words
An input/output structure as in claim 15, further comprising a metal interconnection layer including: an anode section connected to the N-region and to the second terminal; and a cathode section connected to the P-region, the first terminal and the electrode, in which: the cathode section laterally surrounds the anode section.
Claim 33
Dependent Claim
219 words
An input/output structure comprising: a semiconductor substrate; a contact pad formed on the substrate; a microelectronic device which is formed on the substrate and connected in circuit between the contact pad and a reference potential; and a thyristor device for protecting the microelectronic device from electrostatic discharge, the thyristor device including: a P-well formed in the substrate; an N-well formed in the substrate laterally adjacent to the P-well; a P-region formed in the N-well; a first terminal connected to the contact pad and to the P-region; an N-region formed in the P-well; a second terminal connected to the reference potential and to the N-region; first circuit means connecting the first terminal to the N-well; second circuit means connecting the second terminal to the P-well; and an electrode formed over a portion of the P-well between the N-region and the N-well for inducing an electric field into said portion; a metal interconnection layer including: an anode section connected to the N-region and to the second terminal; and a cathode section connected to the P-region, the first terminal and the electrode, in which the cathode section laterally surrounds the anode section; a capacitor connected between the first terminal and the electrode; and a resistor connected between the second terminal and the electrode, in which: the cathode section laterally surrounds the resistor.
Claim 34
Dependent Claim
219 words
An input/output structure comprising: a semiconductor substrate; a contact pad formed on the substrate; a microelectronic device which is formed on the substrate and connected in circuit between the contact pad and a reference potential; and a thyristor device for protecting the microelectronic device from electrostatic discharge, the thyristor device including: a P-well formed in the substrate; an N-well formed in the substrate laterally adjacent to the P-well; a P-region formed in the N-well; a first terminal connected to the contact pad and to the P-region; an N-region formed in the P-well; a second terminal connected to the reference potential and to the N-region; first circuit means connecting the first terminal to the N-well; second circuit means connecting the second terminal to the P-well; and an electrode formed over a portion of the P-well between the N-region and the N-well for inducing an electric field into said portion; a metal interconnection layer including: an anode section connected to the N-region and to the second terminal; and a cathode section connected to the P-region, the first terminal and the electrode, in which the cathode section laterally surrounds the anode section; a capacitor connected between the first terminal and the electrode; and a resistor connected between the second terminal and the electrode, in which: the cathode section laterally surrounds the resistor.
Claim 35
Dependent Claim
15 words
An input/output structure as in claim 29, in which the resistor comprises an N-well resistor.
Claim 36
Dependent Claim
21 words
An input/output structure as in claim 29, in which a portion of the cathode section constitutes a plate of the capacitor.
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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) | 2000-10-27 | 2001-04-28 | 2001-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-27 | 2005-04-28 | 2005-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-27 | 2009-04-28 | 2009-10-28 | $7700.00 | Window Closed / Lapsed |