Bell Telephone Laboratories

At&t Bell Laboratories

American Telephone & Telegraph Co., At&t Bell Laboratories

Peter W Shackle

Adrian R Hartman

Terence J Riley

William F MacPherson

James A Davis

Robert S Scott

Harry E Mussman

Joseph E Berthold

Robert Leonard Pritchett

Bernard T Murphy

James C North

Frederick A D'Altroy

Richard M Jacobs

Alfred Urquhart MacRae

George W Reutlinger

Robert S D'Angelo

To switch a first gated diode switch (GDSL1) to the 'OFF' state requires a voltage applied to the gate which is more positive than that of the anode or cathode and a sourcing of current into the gate of substantially the same order of magnitude as flows between the anode and cathode of the first switch. Control circuitry, which uses a second gated diode switch (GDSC) coupled by the cathode to the gate of the first switch (GDSL1), is used to control the state of the first switch (GDSL1). The control circuitry also comprises a first branch circuit coupled to the anode of the GDSC and to a first potential source V1 and a second branch circuit coupled to the anode of GDSC and to a second potential source V2 which is of a lower potential than V1. The second branch circuit has a high voltage and high current capability switch in series between V2 and the anode of GDSC. The first branch circuit has a high voltage but modest current handling switch in series between V1 and the anode of GDSC. The second branch circuit is used to provide a surge of current if and when needed during the current break operation to turn GDSL1 to an OFF state and the first branch circuit is used to maintain the state of the load switch. The second branch circuit can be shared by many control circuits.

Control circuitry using two branch circuits for high voltage solid-state

A high voltage solid-state switch, which provides bidirectional blocking, consists of a first p- type semiconductor body separated from a support member (semiconductor substrate) by a dielectric layer with a p+ type anode region located at one end of the semiconductor body, an n+ type cathode region located at the other end, and an n+ type gate region located between the anode and cathode regions. A second p type region of higher impurity concentration than the semiconductor body surrounds the cathode region. Separate low resistance electrical contacts are made to the anode, cathode, and gate regions and to the substrate. The switch is capable of switching from an 'ON' and conducting state to an 'OFF' (blocking) state by adjusting the potential of the gate region and without having to adjust the potential of the anode or cathode regions.

High voltage dielectrically isolated solid-state switch

A high voltage solid-state switch, which provides bidirectional blocking, consists of a first p- type semiconductor body having a major surface and being separated from a support member (semiconductor substrate) by a dielectric layer with a p+ type anode region located at one end of the semiconductor body and having a portion which is common with the major surface, an n+ type cathode region located at the other end and having a portion which is common with the major surface, and an n+ type gate region having a portion which is common with the major surface and in one embodiment being located essentially between the anode and cathode regions and in another embodiment being located other than directly between the anode and cathode regions. A second p type region of higher impurity concentration than the semiconductor body surrounds the cathode region. An n+ type semiconductor layer is sandwiched between the semiconductor body and the dielectric layer. Separate low resistance electrical contacts are made to the anode, cathode, and gate regions and to the substrate. The switch is capable of switching from an 'ON' and conducting state to an 'OFF' (blocking) state by adjusting the potential of the gate region and without having to adjust the potential of the anode or cathode regions.

High voltage dielectrically isolated dual gate solid-state switch

A high voltage solid-state switch, which provides bidirectional blocking, consists of a first p- type semiconductor body separated from a support member (semiconductor substrate) by a dielectric layer with a p+ type anode region located at one end of the semiconductor body, an n+ type cathode region located at the other end. An n+ type gate region exists in a portion of the semiconductor body other than the portion which directly separates the anode and cathode regions. A second p type region of higher impurity concentration than the semiconductor body surrounds the cathode region. Separate low resistance electrical contacts are made to the anode, cathode, and gate regions and to the substrate. The switch is capable of switching from an 'ON' and conducting state to an 'OFF' (blocking) state by adjusting the potential of the gate region and without having to adjust the potential of the anode or cathode regions.

High voltage dielectrically isolated remote gate solid-state switch

A high voltage solid-state switch, which provides bidirectional blocking, consists of a first n type semiconductor body separated from a support member (semiconductor substrate) by a dielectric layer with a p+ type anode region located at one end of the semiconductor body, an n+ type cathode region located at the other end, and an n+ type gate region located between the anode and cathode regions. A second p type region of lower impurity concentration than the anode region surrounds the cathode region so as to separate it from the bulk portion of the semiconductor body. Separate low resistance electrical contacts are made to the anode, cathode, and gate regions and to the substrate. The switch is capable of switching from an 'ON' and conducting state to an 'OFF' (blocking) state by adjusting the potential of the gate region and without having to adjust the potential of the anode or cathode regions.

High voltage solid-state switch

A high voltage solid-state switch, which provides bidirectional blocking, consists of a first p- type semiconductor body on an n type semiconductor substrate. A p+ type anode region and an n+ type cathode region exist in portions of the semiconductor body. A second p type region of higher impurity concentration than the semiconductor body surrounds the cathode region. The anode region and second p type region are separated from each other by a portion of the semiconductor body. The semiconductor substrate, which acts as a gate, has an electrode connected thereto. Separate electrodes are connected to the anode and cathode regions.

High voltage junction solid-state switch

A gated diode switch (GDS1, GDS3, GDS4, GDS10) requires a voltage applied to the gate which is more positive than that of the anode and cathode in order to break current flow between the anode and cathode. In addition, a current of at least the same order of magnitude as flows between anode and cathode must flow into the gate of the switch to break current flow. The use of a second gated diode switch (GDS2, GDS20) coupled by the cathode (28, 280) to the gate of a gated diode switch (GDS1, GDS3, GDS4, GDS10) which is to be controlled provides a high voltage and current capability means for cutting off (interrupting) or inhibiting current flow through the gated diode switch (GDS1, GDS3, GDS4, GDS10). The state of a gated diode switch (GDS1, GDS3, GDS4, GDS10) is thus controlled by a second gated diode switch (GDS2, GDS20). The state of the second gated diode switch (GDS2, GDS20) is controlled by a circuitry (A, A0) consisting of an n-p-n transistor (Q1, Q10), at least one p-n-p transistor (Q2, Q20), and at least one diode (D2, D20, D3, D4).

Control circuitry for high voltage solid-state switches

To switch a first gated diode switch (GDS1) to the 'OFF' state requires a voltage applied to the gate which is more positive than that of the anode or cathode and a sourcing of current into the gate of substantially the same order of magnitude as flows between the anode and cathode of the first switch. Control circuitry, which uses a second gated diode switch (GDSC) coupled by the cathode to the gate of the first switch (GDS1), is used to control the state of the first switch (GDS1). The control circuitry comprises a first branch circuit coupled to the gate of GDSC and to a first potential source +V1 and a second branch circuit coupled to the anode of GDSC and to a second potential source V2. The first branch circuit is connected to the gate of the second switch (GDSC) and controls the state thereof. The second branch circuit helps switch the first switch to the OFF state by providing a single current pulse or a plurality of current pulses into the gate of the first switch.

Control circuitry using a pull-down transistor for high voltage

To switch a first gated diode switch (GDS1) to the 'OFF' state requires a voltage applied to the gate which is more positive than that of the anode or cathode and a sourcing of current into the gate of substantially the same order of magnitude as flows between the anode and cathode of the first switch. Control circuitry, which uses a second gated diode switch (GDSC) coupled by the cathode to the gate of the first switch (GDS1), is used to control the state of the first switch (GDS1). The control circuitry comprises a first branch circuit coupled to the gate of GDSC and to a first potential source +V1, a second branch circuit coupled to the anode of GDSC and to a second potential source +V2, and a third branch circuit coupled to the anode of GDSC and to a third potential source +V3. The first branch circuit is connected to the gate of the second switch (GDSC) and controls the state thereof. The second branch circuit maintains the state of the load switch (GDS1) and is adapted to supply up to a preselected maximum amount of current into the anode of GDSC and then to automatically reduce the amount of supplied current substantially. The third branch circuit is used to provide a surge of current during a current break operation to turn GDS1 to an OFF state.

A solid-state protector circuit utilizes the combination of two zener diodes (Z1, Z2), a resistor (R1), a capacitor (C1), and a gated diode switch (GDS) to facilitate the rapid discharge of high voltage transients.

Solid-state protector circuitry using gated diode switch

A high voltage solid-state switch uses a dielectrically isolated lightly doped p- type semiconductor body with a heavily doped p+ type anode region, a heavily doped n+ type gate region, a moderately doped p type shield region, and a heavily doped n+ type cathode region. The shield region surrounds the cathode region. Separate electrodes contact the anode, gate, shield, and cathode regions. The gate and cathode regions also act as the collector-emitter output circuitry of an n-p-n transistor with the shield region acting as the base. With the shield (base) region forward-biased with respect to the cathode or gate regions, the n-p-n transistor is biased on and the collector and emitter are rapidly pulled close to each other in potential. With proper operating potentials applied to the anode and cathode regions, the switch rapidly assumes an 'ON' state when the potential of the shield (base) region is set to a level which biases the n-p-n transistor ON. The integral n-p-n transistor serves to rapidly turn the switch to the ON state and only marginally increases the amount of silicon area needed to implement the switch.

Integral turn-on high voltage switch

To switch a first gated diode switch (GDS) to the 'OFF' state requires a voltage applied to the gate which is more positive than that of the anode or cathode and the sourcing of current into the gate which is of the same order of magnitude as flows between the anode and cathode. Control circuitry, which uses a second GDS coupled by the cathode to the gate of the first GDS, is used to control the state of the first GDS. The state of the second GDS is controlled by a branch circuit having a relatively modest current handling capability. An n-p-n junction transistor has the emitter and collector coupled to the cathode and gate, respectively, of the first GDS, and has the base coupled through a p-n-p transistor to the input terminal of the control circuitry. The n-p-n transistor facilitates a quick turn-on of the first GDS by rapidly bringing the potentials of the gate and cathode of the first GDS to levels which are close together.

Control circuitry using a pull-down transistor for high voltage field

A structure for achieving closely spaced high voltage devices in integrated circuits. The devices are formed in single crystalline tubs (11) in a polycrystalline substrate (10). In order to prevent the potential of the substrate from causing breakdown of the devices, there is included between the single crystalline tubs and the polycrystalline substrate a semi-insulating layer (13) which has trapping states capable of taking on charge from the single crystalline region. The shielding provided by the semi-insulating layer permits the surface regions of the device to be made closer to the polycrystalline substrate and the tubs to be made more shallow.

Dielectrically isolated high voltage semiconductor devices

Integrated circuit complementary transistors for high voltage switching applications are fabricated in separate dielectrically-isolated pockets (12), (14) of high resistivity silicon, supported in a conductive medium (11) such as polycrystalline silicon, using surface adjacent conductivity type zones constituting emitter (19), (23), base (16), (20) and collector zones (17), (21). In one embodiment using high resistivity (75-300 ohm cm) silicon, referred to as .pi. material, for the material of the pocket, one transistor is a PN.pi.P device, and the other is an NP.pi.N. In the PN.pi.P the reverse-biased base-collector pn junction is the interface between the N base zone (16) and the .pi. portion (12) of the collector zone. In the NP.pi.N transistor the base-collector junction is the interface between the lightly doped .pi. extension (14) of the base zone (20) and the N collector zone (21). A connection (32) is provided to the conductive substrate to enable application of a suitable potential thereto.

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Bridgewater, NJ, United States of America

Peter W Shackle