National Semiconductor Corporation

Texas Instruments Corporation

Agilent Technologies, Inc.

Avago Technologies General IP (singapore) Pte. Ltd.

Micron Technology Incorporated

Sandeep Raj Bahl

Constantin Bulucea

William David French

Jeng-Jiun Yang

Donald M Archer

D Courtney Parker

Michael Douglas Seeman

Peter B Johnson

Jamal Ramdani

Prasad Chaparala

Nicolas J Moll

Glenn Hoch Rankin

David I Anderson

Paul L Brohlin

Abdalla Aly Naem

Virginia Robbins

Karen L Seaward

Mark R Hueschen

David Courtney Parker

Yu-Min Houng

Richard W Foote, Jr

Fred Sugihwo

Grant L Smith

David W Bigelow

Daniel Ruiz Flores

Frederick P LaMaster

Daniel Ruizflores

In described examples, a first transistor has: a drain coupled to a source of a depletion-mode transistor; a source coupled to a first voltage node; and a gate coupled to a control node. A second transistor has: a drain coupled to a gate of the depletion-mode transistor; a source coupled to the first voltage node; and a gate coupled through at least one first logic device to an input node. A third transistor has: a drain coupled to the gate of the depletion-mode transistor; a source coupled to a second voltage node; and a gate coupled through at least one second logic device to the input node.

Method and circuitry for controlling a depletion-mode transistor

One example includes a method for surge-testing a gallium nitride (GaN) transistor device-under-test (DUT) that includes at least one GaN transistor device. The method includes inserting the GaN transistor DUT into a test fixture comprising an inductor such that the inductor is coupled to the GaN transistor device to form a switching power regulator. The method also includes operating the switching power regulator at a DUT operating voltage to generate an output current through the inductor based on a DUT input voltage and a duty-cycle. The method also includes controlling an excitation voltage source to provide a voltage surge-strike to the GaN transistor DUT. The method also includes measuring the output current and the DUT input voltage at least one of during and after the voltage surge-strike. The method further includes storing the measured output current and the measured DUT input voltage in a memory to specify device characteristics of the GaN transistor DUT.

System and method for surge-testing a gallium nitride transistor device

Disclosed examples include methods, integrated circuits and switch circuits including a driver circuit and a silicon transistor or other current source circuit coupled with a gallium nitride or other high electron mobility first transistor, where the driver operatives in a first mode to deliver a control voltage signal to the first transistor, and in a second mode in response to a detected overvoltage condition associated with the first transistor to control the current source circuit to conduct a sink current from the first transistor to affect a control voltage to at least partially turn on the first transistor.

Overvoltage protection and short-circuit withstanding for gallium nitride devices

A high-voltage transistor (HVT) structure adapts a low-voltage transistor (LUT) to high-voltage environments. The HVT structure includes a drain node, a source node, a control gate, and a field electrode. The drain node and the source node define a conductive channel, in which mobilized charges are regulated by the control gate. While being isolated from the control gate, the field electrode is configured to spread the mobilized charges in response to a field voltage. The field electrode is structured and routed to prevent charge sharing with any one of the drain node, source node, or control gate. Advantageously, the isolated field electrode minimizes the capacitance of the control gate as well as the drain and source nodes, such that the HVT can switch with less power loss and a more robust performance in a high-voltage environment.

High voltage device with multi-electrode control

Disclosed examples include systems to determine an on-state impedance of a high voltage transistor, and measurement circuits to measure the drain voltage of a drain terminal of the high voltage transistor during switching, including an attenuator circuit to generate an attenuator output signal representing a voltage across the high voltage transistor when the high voltage transistor is turned on, and a differential amplifier to provide an amplified sense voltage signal according to the attenuator output signal. The attenuator circuit includes a clamp transistor coupled with the drain terminal of the high voltage transistor to provide a sense signal to a first internal node, a resistive voltage divider circuit to provide the attenuator output signal based on the sense signal, and a first clamp circuit to limit the sense signal voltage when the high voltage transistor is turned off.

High-resolution power electronics measurements

A high-voltage transistor (HVT) structure adapts a low-voltage transistor (LVT) to high-voltage environments. The HVT structure includes a drain node, a source node, a control gate, and a field electrode. The drain node and the source node define a conductive channel, in which mobilized charges are regulated by the control gate. While being isolated from the control gate, the field electrode is configured to spread the mobilized charges in response to a field voltage. The field electrode is structured and routed to prevent charge sharing with any one of the drain node, source node, or control gate. Advantageously, the isolated field electrode minimizes the capacitance of the control gate as well as the drain and source nodes, such that the HVT can switch with less power loss and a more robust performance in a high-voltage environment.

A method includes forming a first epitaxial layer over a semiconductor substrate and etching the first epitaxial layer to form multiple separated first epitaxial regions. The method also includes forming a second epitaxial layer over the etched first epitaxial layer. Each epitaxial layer includes at least one Group III-nitride, and the epitaxial layers collectively form a buffer. The method further includes forming a device layer over the buffer and fabricating a semiconductor device using the device layer. The second epitaxial layer could include second epitaxial regions substantially only on the first epitaxial regions. The second epitaxial layer could also cover the first epitaxial regions and the substrate, and the second epitaxial layer may or may not be etched. The device layer could be formed during the same operation used to form the second epitaxial layer.

Growth of multi-layer group III-nitride buffers on large-area silicon substrates and other substrates

A semiconductor device includes a first layer and a second layer over the first layer. The first and second layers are configured to form an electron gas layer at an interface of the first and second layers. The semiconductor device also includes an Ohmic contact and multiple conductive vias through the second layer. The conductive vias are configured to electrically couple the Ohmic contact to the electron gas layer. The conductive vias could have substantially vertical sidewalls or substantially sloped sidewalls, or the conductive vias could form a nano-textured surface on the Ohmic contact. The first layer could include Group III-nitride nucleation, buffer, and channel layers, and the second layer could include a Group III-nitride barrier layer.

Ohmic contact schemes for group III-V devices having a two-dimensional electron gas layer

A semiconductor structure, which serves as the core of a semiconductor fabrication platform, has a combination of empty-well regions and filled-well regions variously used by electronic elements, particularly insulated-gate field-effect transistors ('IGFETs'), to achieve desired electronic characteristics. A relatively small amount of semiconductor well dopant is near the top of an empty well. A considerable amount of semiconductor well dopant is near the top of a filled well. Some IGFETs (, and) utilize empty wells (, and) in achieving desired transistor characteristics. Other IGFETs (, and) utilize filled wells (, and) in achieving desired transistor characteristics. The combination of empty and filled wells enables the semiconductor fabrication platform to provide a wide variety of high-performance IGFETs from which circuit designers can select particular IGFETs for various analog and digital applications, including mixed-signal applications.

Configuration and fabrication of semiconductor structure using empty and filled wells

An enhancement-mode group III-N high electron mobility transistor (HEMT) with a reverse polarization cap is formed in a method that utilizes a reverse polarization cap structure, such as an InGaN cap structure, to deplete the two-dimensional electron gas (2DEG) and form a normally off device, and a spacer layer that lies below the reverse polarization cap structure and above the barrier layer of the HEMT which allows the reverse polarization cap layer to be etched without etching into the barrier layer.

Manufacturable enhancement-mode group III-N HEMT with a reverse polarization cap

An asymmetric insulated-gate field-effect transistor (or) has a source (or) and a drain (or) laterally separated by a channel zone (or) of body material (or) of a semiconductor body. A gate electrode (or) overlies a gate dielectric layer (or) above the channel zone. A more heavily doped pocket portion (or) of the body material extends largely along only the source. The source has a main source portion (M orM) and a more lightly doped lateral source extension (E orE). The drain has a main portion (M orM) and a more lightly doped lateral drain extension (E orE). The drain extension is more lightly doped than the source extension. The maximum concentration of the semiconductor dopant defining the two extensions occurs deeper in the drain extension than in the source extension. Additionally or alternatively, the drain extension extends further laterally below the gate electrode than the source extension. These features enable the threshold voltage to be highly stable with operational time.

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Sandeep Raj Bahl