Patent US5510641A successfully refreshed from Google Patents.
US5510641A
Expired / Lapsed
US
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Majority carrier power diode
Assignee: WASHINGTON, University of
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Filing: 1993-03-31
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Granted: 1996-04-23
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Expires: 2013-03-31
Abstract
Abstract A power diode having substantially no reverse-recovery time and relatively high conductance. The power diode is a majority carrier semiconductor having a structure that is similar to that of a metal oxide semiconductor field effect transistor (MOSFET), in that it includes a source, a drain, a gate, and a body. In one embodiment, to increase conductance of the power diode, a linked-cell configuration that reverses the geometry of a conventional cell-type MOSFET is employed, thereby increasing the width of a conductance channel over that of a conventional MOSFET, and compensating for a relatively low level of inversion in the channel region. Negative and positive feedback circuits are used to further improve the conductance of the power diode by dynamically setting a bias voltage applied between the gate and the source to a level just below a threshold voltage. In the positive feedback circuit, the magnitude of the bias voltage is greater than the threshold voltage if the power diode is forward biased, but substantially reduced if the power diode is reverse biased, thereby minimizing its turn-on delay without risking reverse conductance. Although separate components are used for biasing the device in the disclosed embodiments, it is contemplated that these components be integrated on a common substrate with the source, drain, and gate in a commercially practiced preferred embodiment. Another embodiment employs a charge carrier region diffused into the body and at least in part underlying the gate. This region provides a variable threshold voltage along the channel and reduces the effective length of the channel to increase its conductance. A threshold voltage ranges between a higher value, VTMAX, adjacent the source, to a lower value, VT, elsewhere in the device.
Inventors
- 👤 Hsian-Pei Yee
- 👤 Peter O. Lauritzen
- 👤 Sinclair S. Yee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:07
CPC Classifications
H; H10; H10D; H10D8/00; H10D30/00; H10D30/60; H10D30/64; H10D30/66; H10D62/00; H10D62/10; H10D62/124; H10D62/126; H10D62/127
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
124 words
A majority carrier semiconductor diode comprising: (a) an N-type region having a conductive contact, forming a drain; (b) a P-type material having a conductive contact, forming a body; (c) an N-type material applied to the P-type material forming the body and having a conductive contact, forming a source; (d) a dielectric material disposed adjacent the source and the drain and having a conductive contact that is not connected to the source or the drain, the conductive contact forming a gate; and (e) biasing means for biasing the gate to provide a conducting N-channel for electrical current flow between the source and the drain for a negative drain-source voltage, while blocking electrical current flow between the source and the drain for a positive drain-source voltage.
Claim 2
Dependent Claim
124 words
A majority carrier semiconductor diode comprising: (a) an N-type region having a conductive contact, forming a drain; (b) a P-type material having a conductive contact, forming a body; (c) an N-type material applied to the P-type material forming the body and having a conductive contact, forming a source; (d) a dielectric material disposed adjacent the source and the drain and having a conductive contact that is not connected to the source or the drain, the conductive contact forming a gate; and (e) biasing means for biasing the gate to provide a conducting N-channel for electrical current flow between the source and the drain for a negative drain-source voltage, while blocking electrical current flow between the source and the drain for a positive drain-source voltage.
Claim 3
Dependent Claim
45 words
The majority carrier semiconductor diode of claim 1, wherein the biasing means provide a gate-source voltage that is less than a threshold voltage, creating a weak inversion layer in the body that does not support conduction unless the drain is more negative than the source.
Claim 4
Dependent Claim
23 words
The majority carrier semiconductor diode of claim 1, wherein the biasing means include negative feedback means for increasing a conductance of the N-channel.
Claim 5
Dependent Claim
23 words
The majority carrier semiconductor diode of claim 1, wherein the biasing means include positive feedback means for increasing a conductance of the N-channel.
Claim 6
Dependent Claim
55 words
The majority carrier semiconductor diode of claim 4, wherein the positive feedback means include means for biasing the gate-source voltage above the magnitude of a threshold voltage when the drain is more negative than the source and biasing the gate-source voltage to a substantially lower voltage if the drain is more positive than the source.
Claim 7
Dependent Claim
111 words
The majority carrier semiconductor diode of claim 1, wherein the P-type material comprising the body includes a P+ region on which the N-type material comprising the source is applied, said P+ region enabling a variable threshold for conductance through the N-type channel ranging between V T and V TMAX and reducing a length of the N-type channel, so that for a negative drain-source voltage: (a) conductance through the N-type channel is initiated with a gate-source voltage less than the threshold voltage V T ; and (b) once said conductance initiated, if the gate-source voltage is increased above the threshold voltage V T , substantially increased conductance through the N-type channel occurs.
Claim 8
Dependent Claim
28 words
The majority carrier semiconductor diode of claim 6, wherein the P+ region underlies at least a portion of the gate and is substantially less than 1.0 μm thick.
Claim 9
Dependent Claim
125 words
A majority carrier semiconductor diode comprising: (a) a P-type region having a conductive contact, forming a drain; (b) an N-type material having a conductive contact, forming a body; (c) a P-type material applied to the N-type material forming the body and having a conductive contact, forming a source; (d) a dielectric material disposed adjacent the source and the drain and having a conductive contact that is not connected to the source or the drain, the conductive contact forming a gate; and (e) biasing means for biasing the gate to provide a conducting P-channel for electrical current flow between the source and the drain for a positive drain-source voltage, while blocking electrical current flow between the drain and the source if the drain-source voltage is negative.
Claim 10
Dependent Claim
125 words
A majority carrier semiconductor diode comprising: (a) a P-type region having a conductive contact, forming a drain; (b) an N-type material having a conductive contact, forming a body; (c) a P-type material applied to the N-type material forming the body and having a conductive contact, forming a source; (d) a dielectric material disposed adjacent the source and the drain and having a conductive contact that is not connected to the source or the drain, the conductive contact forming a gate; and (e) biasing means for biasing the gate to provide a conducting P-channel for electrical current flow between the source and the drain for a positive drain-source voltage, while blocking electrical current flow between the drain and the source if the drain-source voltage is negative.
Claim 11
Dependent Claim
45 words
The majority carrier semiconductor diode of claim 8, wherein the biasing means provide a gate-source voltage that is less than a threshold voltage, creating a weak inversion layer in the body that does not support conduction unless the drain is more positive than the source.
Claim 12
Dependent Claim
23 words
The majority carrier semiconductor diode of claim 8, wherein the biasing means include negative feedback means for increasing a conductance of the P-channel.
Claim 13
Dependent Claim
23 words
The majority carrier semiconductor diode of claim 8, wherein the biasing means include positive feedback means for increasing a conductance of the P-channel.
Claim 14
Dependent Claim
55 words
The majority carrier semiconductor diode of claim 11, wherein the positive feedback means include means for biasing the gate-source voltage above the magnitude of a threshold voltage when the drain is more positive than the source and biasing the gate-source voltage to a substantially lower voltage if the drain is more negative than the source.
Claim 15
Dependent Claim
117 words
The majority carrier semiconductor diode of claim 8, wherein the N-type material comprising the body includes an N+ region on which the P-type material comprising the source is applied, said N+ region enabling a variable threshold for conductance through the P-type channel ranging between V T and V T MAX and reducing a length of the P-type channel, so that for a positive drain-source voltage: (a) conductance of the N-type channel is initiated with a gate-source voltage having a magnitude less than the threshold voltage V T ; and then, (b) if the magnitude of the gate-source voltage is increased above that of the threshold voltage V T , substantially increased conductance through the P-type channel occurs.
Claim 16
Dependent Claim
28 words
The majority carrier semiconductor diode of claim 6, wherein the N+ region underlies at least a portion of the gate and is substantially less than 1.0 μm thick.
Claim 17
Dependent Claim
178 words
A biasing circuit for operating a metal oxide field effect transistor (MOSFET) as a diode that conducts electrical current between a drain and a source of the MOSFET in a forward direction, but not in a reverse direction, said biasing circuit comprising: (a) conductance monitoring means for sensing one of: (i) an electrical current flowing through a drain and a source of a MOSFET, or (ii) a voltage across the drain and source of the MOSFET, said conductance monitoring means producing a feedback signal indicative of said one of the electrical current and the voltage; and (b) biasing means, coupled to the conductance monitoring means to receive the feedback signal, for providing a bias voltage in response to the feedback signal, said bias voltage being supplied to a gate of the MOSFET, said biasing means controlling the bias voltage so that the bias voltage is less than a threshold voltage necessary to bias the MOSFET into conductance in the reverse direction, but sufficient to minimize conductance through a body diode portion of the MOSFET in the forward direction.
Claim 18
Dependent Claim
178 words
A biasing circuit for operating a metal oxide field effect transistor (MOSFET) as a diode that conducts electrical current between a drain and a source of the MOSFET in a forward direction, but not in a reverse direction, said biasing circuit comprising: (a) conductance monitoring means for sensing one of: (i) an electrical current flowing through a drain and a source of a MOSFET, or (ii) a voltage across the drain and source of the MOSFET, said conductance monitoring means producing a feedback signal indicative of said one of the electrical current and the voltage; and (b) biasing means, coupled to the conductance monitoring means to receive the feedback signal, for providing a bias voltage in response to the feedback signal, said bias voltage being supplied to a gate of the MOSFET, said biasing means controlling the bias voltage so that the bias voltage is less than a threshold voltage necessary to bias the MOSFET into conductance in the reverse direction, but sufficient to minimize conductance through a body diode portion of the MOSFET in the forward direction.
Claim 19
Dependent Claim
89 words
The biasing circuit of claim 15, wherein the monitoring means comprise: (a) a voltage comparator having inverting and non-inverting inputs and an output; (b) an input resistor coupling one of the source and the drain of the MOSFET to one of inverting and non-inverting inputs of the voltage comparator, the other of the source and the drain being coupled to the other of the inverting and non-inverting inputs; and (c) a feedback resistor coupled between the output and one of the inverting and non-inverting inputs of the voltage comparator.
Claim 20
Dependent Claim
103 words
The biasing circuit of claim 15, further comprising: (a) a diode having two terminals, one terminal being coupled to one of the drain and the source; and (b) a resistor having one end coupled to one of the inverting and non-inverting inputs and to one of the source and the drain of the MOSFET, and another end coupled to the input resistor and to another terminal of the diode, current flow through said diode corresponding to current flow through an internal body diode of the MOSFET and a voltage drop across the resistor being indicative of current flow through the internal body diode.
Claim 21
Dependent Claim
148 words
The biasing circuit of claim 15, wherein the conductance monitoring means comprise: (a) a voltage comparator having inverting and non-inverting inputs and an output; (b) a diode having two terminals; and (c) a resistor having two ends, one end being coupled to one of the source and the drain of the MOSFET and to one of the inverting and non-inverting inputs of the voltage comparator, and the other end of the resistor being coupled to one terminal of the diode and to the other of the inverting and non-inverting inputs of the voltage comparator, the other terminal of the diode being coupled to the other of the source and the drain of the MOSFET, current flow through said diode corresponding to current flow through an internal body diode of the MOSFET and a voltage drop across the resistor being indicative of current flow through the internal body diode.
Claim 22
Dependent Claim
30 words
The biasing circuit of claim 15, wherein the biasing means comprise a push-pull circuit connected to a voltage source and to one of the drain and source of the MOSFET.
Claim 23
Dependent Claim
163 words
A biasing circuit for biasing a majority charge carrier device to conduct an electrical current in a forward direction and block a flow of electrical current in a reverse direction through the device, the majority charge carrier device having a body, a gate, a source, and a drain, said bias comprising: means for sensing a voltage between a source and a drain of a majority charge carrier device and producing a feedback signal in response to the voltage; and means for producing a control signal in response to the feedback voltage, said control signal being coupled to a gate of the majority charge carrier device, said means setting a magnitude of the control signal so that it is less than a threshold signal that would enable conduction between the source and the drain in a reverse direction, but so that it causes a conductance between the source and the drain in a channel formed within a body of the majority charge carrier device.
Claim 24
Dependent Claim
163 words
A biasing circuit for biasing a majority charge carrier device to conduct an electrical current in a forward direction and block a flow of electrical current in a reverse direction through the device, the majority charge carrier device having a body, a gate, a source, and a drain, said bias comprising: means for sensing a voltage between a source and a drain of a majority charge carrier device and producing a feedback signal in response to the voltage; and means for producing a control signal in response to the feedback voltage, said control signal being coupled to a gate of the majority charge carrier device, said means setting a magnitude of the control signal so that it is less than a threshold signal that would enable conduction between the source and the drain in a reverse direction, but so that it causes a conductance between the source and the drain in a channel formed within a body of the majority charge carrier device.
Claim 25
Dependent Claim
51 words
The biasing circuit of claim 20, wherein the means for producing the control signal increases its magnitude to exceed the threshold voltage once conductance in the channel of the majority charge carrier device has been initiated, thereby increasing the conductance of the electrical current flowing between the source and the drain.
Claim 26
Dependent Claim
287 words
A biasing circuit for biasing a majority charge carrier device to conduct an electrical current in a forward direction and block a flow of electrical current in a reverse direction through the device, the majority charge carrier device having a body, a gate, a source, and a drain, said biasing circuit comprising: leakage current monitoring means, coupled to a source and a gate of a majority charge carrier device, for monitoring a leakage current through the majority charge carrier device and controlling a voltage applied to the gate of said device as a function of variations in the leakage current through said device, said static conduction mode enabling current to flow in a forward direction between the source and a drain of said device while the voltage applied to the gate is less than a threshold voltage that would cause conduction of electrical current between the source and the drain in a reverse direction; and current comparator means, coupled to the majority charge carrier device to sense electrical current flow between a body and the drain of the majority charge carrier device, and in response to the electrical current, controlling a gate voltage applied to the gate of the majority charge carrier device to control conduction between the source and the drain of said device, said current comparator means applying a voltage greater than the threshold voltage to the gate to initiate conduction in a dynamic mode after conduction of the electrical current between the source and the drain in a forward direction has already been initiated in the static mode and the electrical current flow has exceeded a predefined level, conductance of the device in the dynamic mode being much greater than in the static mode.
Claim 27
Dependent Claim
287 words
A biasing circuit for biasing a majority charge carrier device to conduct an electrical current in a forward direction and block a flow of electrical current in a reverse direction through the device, the majority charge carrier device having a body, a gate, a source, and a drain, said biasing circuit comprising: leakage current monitoring means, coupled to a source and a gate of a majority charge carrier device, for monitoring a leakage current through the majority charge carrier device and controlling a voltage applied to the gate of said device as a function of variations in the leakage current through said device, said static conduction mode enabling current to flow in a forward direction between the source and a drain of said device while the voltage applied to the gate is less than a threshold voltage that would cause conduction of electrical current between the source and the drain in a reverse direction; and current comparator means, coupled to the majority charge carrier device to sense electrical current flow between a body and the drain of the majority charge carrier device, and in response to the electrical current, controlling a gate voltage applied to the gate of the majority charge carrier device to control conduction between the source and the drain of said device, said current comparator means applying a voltage greater than the threshold voltage to the gate to initiate conduction in a dynamic mode after conduction of the electrical current between the source and the drain in a forward direction has already been initiated in the static mode and the electrical current flow has exceeded a predefined level, conductance of the device in the dynamic mode being much greater than in the static mode.
Claim 28
Dependent Claim
18 words
The biasing circuit of claim 22, wherein the current comparator means have substantially a zero forward voltage drop.
Claim 29
Independent Claim
133 words
A method for operating a MOSFET as a diode, comprising the steps of: (a) monitoring one of: (i) an electrical current flowing through a drain and a source of a MOSFET, producing a feedback signal indicative of said electrical current; and (ii) a voltage across the drain and source of the MOSFET, producing a feedback signal indicative of said one of the electrical current and the voltage; (b) providing a bias voltage to a gate of the MOSFET in response to the feedback signal; and (c) controlling the bias voltage so that it is less than a first threshold voltage necessary to bias the MOSFET into conductance in the reverse direction, but substantially greater than a second threshold that enables conductance in the forward direction through a body diode portion of the MOSFET.
Claim 30
Independent Claim
133 words
A method for operating a MOSFET as a diode, comprising the steps of: (a) monitoring one of: (i) an electrical current flowing through a drain and a source of a MOSFET, producing a feedback signal indicative of said electrical current; and (ii) a voltage across the drain and source of the MOSFET, producing a feedback signal indicative of said one of the electrical current and the voltage; (b) providing a bias voltage to a gate of the MOSFET in response to the feedback signal; and (c) controlling the bias voltage so that it is less than a first threshold voltage necessary to bias the MOSFET into conductance in the reverse direction, but substantially greater than a second threshold that enables conductance in the forward direction through a body diode portion of the MOSFET.
Claim 31
Independent Claim
147 words
A method for operating a majority charge carrier device to conduct an electrical current in a forward direction and block the flow of electrical current in a reverse direction through the device, comprising the steps of: (a) sensing one of a voltage between a source and a drain of a majority charge carrier device, and a current flow through the majority charge carrier device, producing a feedback signal; and (b) producing a control signal in response to the feedback voltage, said control signal being coupled to a gate of the majority charge carrier device, said control signal being lower in magnitude than a threshold voltage, V T , that would enable conduction between the source and drain in a reverse direction, but sufficient to cause a conductance in a forward direction between the source and the drain within a channel produced in the majority charge carrier device.
Claim 32
Independent Claim
147 words
A method for operating a majority charge carrier device to conduct an electrical current in a forward direction and block the flow of electrical current in a reverse direction through the device, comprising the steps of: (a) sensing one of a voltage between a source and a drain of a majority charge carrier device, and a current flow through the majority charge carrier device, producing a feedback signal; and (b) producing a control signal in response to the feedback voltage, said control signal being coupled to a gate of the majority charge carrier device, said control signal being lower in magnitude than a threshold voltage, V T , that would enable conduction between the source and drain in a reverse direction, but sufficient to cause a conductance in a forward direction between the source and the drain within a channel produced in the majority charge carrier device.
Claim 33
Dependent Claim
50 words
The method of claim 25, further comprising the step of increasing the control signal to exceed the threshold voltage once the conductance in the forward direction between the source and the drain of the majority charge carrier has been initiated, thereby increasing the conductance of the majority charge carrier device.
Claim 34
Dependent Claim
19 words
The method of claim 25, wherein the step of sensing includes the step of producing a negative feedback signal.
Claim 35
Dependent Claim
19 words
The method of claim 25, wherein the step of sensing includes the step of producing a positive feedback signal.
Claim 36
Dependent Claim
93 words
The method of claim 25, wherein the majority charge carrier device comprises an N-type region having a conductive contact, forming the drain; a P-type material applied to the N-type region and having a conductive contact, forming the body; and an N-type material applied to the P-type material that forms the body, and having a conductive contact, forming a gate, further comprising the step of creating a weak N-inversion layer channel in the body of the majority charge carrier device that does not support conduction unless the drain is more negative than the source.
Claim 37
Dependent Claim
53 words
The method of claim 29, wherein the step of producing the control signal comprises the steps of biasing a gate-source voltage above a predefined magnitude when the drain is more negative than the source and biasing the gate-source voltage to a substantially lower magnitude if the drain is more positive than the source.
Claim 38
Dependent Claim
93 words
The method of claim 25, wherein the majority charge carrier device comprises a P-type region having a conductive contact, forming the drain; an N-type material applied to the P-type region and having a conductive contact, forming the body; and a P-type material applied to the N-type material that forms the body, and having a conductive contact, forming a gate, further comprising the step of creating a weak P-inversion layer channel in the body of the majority charge carrier device that does not support conduction unless the drain is more positive than the source.
Claim 39
Dependent Claim
53 words
The method of claim 31, wherein the step of producing the control signal comprises the steps of biasing a gate-source voltage above a predefined magnitude when the drain is more positive than the source and biasing the gate-source voltage to a substantially lower magnitude if the drain is more negative than the source.
Claim 40
Dependent Claim
68 words
The method of claim 25, further comprising the step of providing a charge carrier region in the majority charge carrier device underlying at least a portion of the gate, said charge carrier region providing a variable threshold voltage along the channel ranging between V T and a greater magnitude voltage, V TMAX , and shortening a length of the channel to produce a higher conductance through the channel.
Claim 41
Dependent Claim
55 words
The method of claim 22, wherein the variable threshold voltage is V TMAX adjacent the source and V T elsewhere, so that when the channel is not conducting, a gate-source voltage is substantially equal to V TMAX , inverting most of the channel, except in a portion of the charge carrier region adjacent the gate.
Claim 42
Dependent Claim
124 words
A majority carrier semiconductor diode comprising: (a) an N-type region having a conductive contact, forming a drain; (b) a P-type material having a conductive contact, forming a body; (c) an N-type material applied to the P-type material forming the body and having a conductive contact, forming a source; (d) a dielectric material disposed adjacent the source and the drain and having a conductive contact, forming a gate; and (e) biasing means for biasing the gate to provide a conducting N-channel for electrical current flow between the source and the drain for a negative drain-source voltage, while blocking electrical current flow between the source and the drain for a positive drain-source voltage, the biasing means including feedback means for increasing a conductance of the N-channel.
Claim 43
Dependent Claim
124 words
A majority carrier semiconductor diode comprising: (a) an N-type region having a conductive contact, forming a drain; (b) a P-type material having a conductive contact, forming a body; (c) an N-type material applied to the P-type material forming the body and having a conductive contact, forming a source; (d) a dielectric material disposed adjacent the source and the drain and having a conductive contact, forming a gate; and (e) biasing means for biasing the gate to provide a conducting N-channel for electrical current flow between the source and the drain for a negative drain-source voltage, while blocking electrical current flow between the source and the drain for a positive drain-source voltage, the biasing means including feedback means for increasing a conductance of the N-channel.
Claim 44
Dependent Claim
20 words
The majority carrier semiconductor of claim 35, wherein the feedback means for increasing a conductance of the N-channel is negative.
Claim 45
Dependent Claim
20 words
The majority carrier semiconductor of claim 35, wherein the feedback means for increasing a conductance of the N-channel is positive.
Claim 46
Dependent Claim
125 words
A majority carrier semiconductor diode comprising: (a) a P-type region having a conductive contact, forming a drain; (b) an N-type material having a conductive contact, forming a body; (c) a P-type material applied to the N-type material forming the body and having a conductive contact, forming a source; (d) a dielectric material disposed adjacent the source and the drain and having a conductive contact, forming a gate; and (e) biasing means for biasing the gate to provide a conducting P-channel for electrical current flow between the source and the drain for a positive drain-source voltage, while blocking electrical current flow between the drain and the source if the drain-source voltage is negative, the biasing means including feedback means for increasing a conductance of the P-channel.
Claim 47
Dependent Claim
125 words
A majority carrier semiconductor diode comprising: (a) a P-type region having a conductive contact, forming a drain; (b) an N-type material having a conductive contact, forming a body; (c) a P-type material applied to the N-type material forming the body and having a conductive contact, forming a source; (d) a dielectric material disposed adjacent the source and the drain and having a conductive contact, forming a gate; and (e) biasing means for biasing the gate to provide a conducting P-channel for electrical current flow between the source and the drain for a positive drain-source voltage, while blocking electrical current flow between the drain and the source if the drain-source voltage is negative, the biasing means including feedback means for increasing a conductance of the P-channel.
Claim 48
Dependent Claim
20 words
The majority carrier semiconductor of claim 38, wherein the feedback means for increasing a conductance of the P-channel is negative.
Claim 49
Dependent Claim
20 words
The majority carrier semiconductor of claim 38, wherein the feedback means for increasing a conductance of the P-channel is positive.
References Cited (Backward Citations)
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