Apparatus and circuits including transistors with different threshold voltages and methods of fabricating the same are disclosed. In one example, a semiconductor structure is disclosed. The semiconductor structure includes: a substrate; an active layer that is formed over the substrate and comprises a plurality of active portions; a polarization modulation layer comprising a plurality of polarization modulation portions each of which is disposed on a corresponding one of the plurality of active portions; and a plurality of transistors each of which comprises a source region, a drain region, and a gate structure formed on a corresponding one of the plurality of polarization modulation portions. The transistors have at least three different threshold voltages.

An all-lateral wide band-gap (WBG) cascode switch device is provided, which includes a source terminal; a gate terminal; a drain terminal; a lateral enhancement-mode silicon semiconductor switch, having a first source electrode, a first drain electrode, and a first gate electrode; and a lateral depletion-mode WBG semiconductor switch disposed laterally apart from and cascoded with the lateral enhancement-mode silicon semiconductor switch, having a second source electrode, a second drain electrode, and a second gate electrode. The first source electrode, the first drain electrode, and the first gate electrode of the lateral enhancement-mode silicon semiconductor switch and the second source electrode, the second drain electrode and the second gate electrode of the lateral depletion-mode WBG semiconductor switch have the same vertical orientation to face the same side.

Power device and packaging thereof. For example, a power device including a silicon transistor and a gallium nitride transistor, the power device comprising: an enhancement-mode silicon transistor; and a depletion-mode gallium nitride transistor coupled to the enhancement-mode silicon transistor; wherein the enhancement-mode silicon transistor includes: a silicon substrate including a first substrate surface and a second substrate surface; a first transistor gate terminal electrically conductively connected to a transistor gate, the transistor gate being located on the first substrate surface of the silicon substrate through a dielectric layer; a first transistor source terminal electrically conductively connected to a first part of the silicon substrate through the first substrate surface; and a first transistor drain terminal electrically conductively connected to a second part of the silicon substrate through the first substrate surface.

In a method of manufacturing a semiconductor device, a memory cell structure covered by a protective layer is formed in a memory cell area of a substrate. A mask pattern is formed. The mask pattern has an opening over a first circuit area, while the memory cell area and a second circuit area are covered by the mask pattern. The substrate in the first circuit area is recessed, while the memory cell area and the second circuit area are protected. A first field effect transistor (FET) having a first gate dielectric layer is formed in the first circuit area over the recessed substrate and a second FET having a second gate dielectric layer is formed in the second circuit area over the substrate as viewed in cross section.

In a method of manufacturing a semiconductor device, a memory cell structure covered by a protective layer is formed in a memory cell area of a substrate. A mask pattern is formed. The mask pattern has an opening over a first circuit area, while the memory cell area and a second circuit area are covered by the mask pattern. The substrate in the first circuit area is recessed, while the memory cell area and the second circuit area are protected. A first field effect transistor (FET) having a first gate dielectric layer is formed in the first circuit area over the recessed substrate and a second FET having a second gate dielectric layer is formed in the second circuit area over the substrate as viewed in cross section.

A transistor arrangement is disclosed. The transistor arrangement includes a first transistor device and a second transistor device. The first transistor device and the second transistor device are connected in series and integrated in a common semiconductor body. The first transistor device is a lateral superjunction transistor device and is integrated in a first device region of the semiconductor body. The second transistor device is a lateral transistor device and is integrated in at least one second device region of the semiconductor body. The at least one second device region is spaced apart from the first device region.

A transistor arrangement is disclosed. The transistor arrangement includes a first transistor device and a second transistor device. The first transistor device and the second transistor device are connected in series and integrated in a common semiconductor body. The first transistor device is a lateral superjunction transistor device and is integrated in a first device region of the semiconductor body. The second transistor device is a lateral transistor device and is integrated in at least one second device region of the semiconductor body. The at least one second device region is spaced apart from the first device region.

A heterojunction device having at least three terminals, the at least three terminals comprising a high voltage terminal, a low voltage terminal and a control terminal. The heterojunction device further comprises at least one main power heterojunction transistor, an auxiliary gate circuit comprising at least one first low-voltage heterojunction transistor, a pull-down circuit comprising a capacitor and a charging path for the capacitor. The heterojunction device further comprises at least one monolithically integrated component, wherein the capacitor is configured to provide an internal rail voltage for the at least one monolithically integrated component.

A heterojunction device having at least three terminals, the at least three terminals comprising a high voltage terminal, a low voltage terminal and a control terminal. The heterojunction device further comprises at least one main power heterojunction transistor, an auxiliary gate circuit comprising at least one first low-voltage heterojunction transistor, a pull-down circuit comprising a capacitor and a charging path for the capacitor. The heterojunction device further comprises at least one monolithically integrated component, wherein the capacitor is configured to provide an internal rail voltage for the at least one monolithically integrated component.

An object is to reduce leakage current and parasitic capacitance of a transistor used for an LSI, a CPU, or a memory. A semiconductor integrated circuit such as an LSI, a CPU, or a memory is manufactured using a thin film transistor in which a channel formation region is formed using an oxide semiconductor which becomes an intrinsic or substantially intrinsic semiconductor by removing impurities which serve as electron donors (donors) from the oxide semiconductor and has larger energy gap than that of a silicon semiconductor. With use of a thin film transistor using a highly purified oxide semiconductor layer with sufficiently reduced hydrogen concentration, a semiconductor device with low power consumption due to leakage current can be realized.