A semiconductor device includes a trench formed in an epitaxial layer and an oxide layer that lines the sidewalls of the trench. The thickness of the oxide layer is non-uniform, so that the thickness of the oxide layer toward the top of the trench is thinner than it is toward the bottom of the trench. The epitaxial layer can have a non-uniform dopant concentration, where the dopant concentration varies according to the thickness of the oxide layer.

A method of fabricating a semiconductor device is provided as follows. A source/drain pattern is formed on a substrate. The source/drain pattern contains silicon atoms and germanium atoms. At least one germanium atom is removed from the germanium atoms of the source/drain pattern.

A method includes forming a first silicide on a substrate after patterning a gate and spacer onto the substrate. A film is deposited over the substrate. A portion of the dielectric film is removed to expose the first silicide. A portion of the first silicide is removed to form a punch through region. A liner is deposited in the punch through region. A metal layer is deposited on the liner. The substrate is annealed to form a second silicide on the substrate.

An integrated circuit structure includes a gate stack over a semiconductor substrate, and an opening extending into the semiconductor substrate, wherein the opening is adjacent to the gate stack. A first silicon germanium region is disposed in the opening, wherein the first silicon germanium region has a first germanium percentage. A second silicon germanium region is over the first silicon germanium region. The second silicon germanium region comprises a portion in the opening. The second silicon germanium region has a second germanium percentage greater than the first germanium percentage. A silicon cap substantially free from germanium is over the second silicon germanium region.

A High Electron Mobility Transistor (HEMT) and a method of forming the same are disclosed. The HEMT includes a first III-V compound layer having a first band gap and a second III-V compound layer having a second band gap over the first III-V compound layer, wherein the second band gap is greater than the first band gap. The HEMT further includes a first oxide layer over the second III-V compound layer; a first interfacial layer over the first oxide layer; and a passivation layer over the first interfacial layer.

A perforating ohmic contact to a semiconductor layer in a semiconductor structure is provided. The perforating ohmic contact can include a set of perforating elements, which can include a set of metal protrusions laterally penetrating the semiconductor layer(s). The perforating elements can be separated from one another by a characteristic length scale selected based on a sheet resistance of the semiconductor layer and a contact resistance per unit length of a metal of the perforating ohmic contact contacting the semiconductor layer. The structure can be annealed using a set of conditions configured to ensure formation of the set of metal protrusions.

A hybrid transistor circuit is disclosed for use in III-Nitride (III-N) semiconductor devices, comprising a Silicon (Si)-based Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), a Group III-Nitride (III-N)-based Field-Effect Transistor (FET), and a driver unit. A source terminal of the III-N-based FET is connected to a drain terminal of the Si-based MOSFET. The driver unit has at least one input terminal, and two output terminals connected to the gate terminals of the transistors respectively. The hybrid transistor circuit is turned on through the driver unit by switching on the Silicon-based MOSFET first before switching on the III-N-based FET, and is turned off through the driver unit by switching off the III-N-based FET before switching off the Silicon-based MOSFET. Also disclosed are integrated circuit packages and semiconductor structures for forming such hybrid transistor circuits. The resulting hybrid circuit provides power-efficient and robust use of III-Nitride semiconductor devices.

A switched-mode power converter includes an inductive storage element and a cascode circuit. The cascode circuit includes a double-gate field effect transistor. A switchable load path of the double-gate field effect transistor is electrically connected in series with the inductive storage element.

A semiconductor device includes a transistor. The transistor includes a source region and a drain region disposed adjacent to a first main surface of a semiconductor substrate, a first gate electrode and a second gate electrode, the first gate electrode being disconnected from the second gate electrode. The transistor further includes a body region. The first gate electrode is adjacent to a first portion of the body region and the second gate electrode is adjacent to a second portion of the body region. The transistor further includes first trenches patterning the first portion of the body region into a first ridge, and second trenches patterning the second portion of the body region into a second ridge. The first gate electrode is arranged in at least one of first trenches, and the second gate electrode is arranged in at least one of the second trenches.

The present disclosure provides a semiconductor device and a method for manufacturing the same. The semiconductor device comprises a substrate, a first III-V compound layer over the substrate, a first passivation layer on the first III-V compound layer, a source region and a drain region. The source region penetrates the first passivation layer to electrically contact the first III-V compound layer. The drain region penetrates the first passivation layer to electrically contact the first III-V compound layer. A sidewall of the first passivation layer contacting with the source region comprises a stair shape.