A complementary transistor pair with an n-type enhancement-mode field effect transistor and a p-type field effect transistor is disclosed. The n-type enhancement-mode field effect transistor uses a metal oxide channel layer having a material selected from SnO.sub.2, ITO, ZnO, SnO.sub.2 and In.sub.2O.sub.3 while the p-type field effect transistor uses a germanium-containing channel layer.

A power semiconductor device has an upper transistor and a lower transistor that is coupled in cascode with the upper transistor. The upper transistor comprises an upper drain, upper gate, and an upper source. The lower transistor comprises a lower drain that is coupled to the upper source, a lower gate, and a lower source that is coupled to the upper gate. The upper transistor is a depletion mode device and has a first saturation current. The lower transistor is an enhancement mode device and has a second saturation current, which is lower than the first saturation current.

Some embodiments of the present disclosure provide a semiconductor device. The semiconductor device includes a first transistor configured to include a first threshold voltage level. The first transistor includes a gate structure. The gate structure includes a first component including a first conductive type. A second transistor configures to include a second threshold voltage level different from the first threshold voltage level. The second transistor includes a gate structure. The gate structure includes a second component including the first conductive type. At least one extra component is disposed over the second component. The least one extra component includes a second conductive type opposite to the first conductive type. The first transistor and the second transistor are coupled such that the number of the least one extra component is determined by a desired voltage difference between the first threshold voltage level and the second threshold voltage level.

GaN-based half bridge power conversion circuits employ control, support and logic functions that are monolithically integrated on the same devices as the power transistors. In some embodiments a low side GaN device communicates through one or more level shift circuits with a high side GaN device. Both the high side and the low side devices may have one or more integrated control, support and logic functions. Some devices employ electro-static discharge circuits and features formed within the GaN-based devices to improve the reliability and performance of the half bridge power conversion circuits.

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.

A voltage detector for detecting whether an input voltage is no lower than a predetermined threshold voltage, includes a reference voltage generator configured to generate a reference voltage, and a comparator configured to receive the input voltage and the reference voltage and to detect whether the input voltage is no lower than the threshold voltage that is determined by the reference voltage. Here, the reference voltage generator includes a first write MOS transistor, a second write MOS transistor, a first output MOS transistor and a second output MOS transistor each including a control gate and a floating gate.

Some embodiments of the present disclosure provide a semiconductor device. The semiconductor device includes a first transistor configured to include a first threshold voltage level. The first transistor includes a gate structure. The gate structure includes a first component including a first conductive type. A second transistor configures to include a second threshold voltage level different from the first threshold voltage level. The second transistor includes a gate structure. The gate structure includes a second component including the first conductive type. At least one extra component is disposed over the second component. The least one extra component includes a second conductive type opposite to the first conductive type. The first transistor and the second transistor are coupled such that the number of the least one extra component is determined by a desired voltage difference between the first threshold voltage level and the second threshold voltage level.

Provided is a semiconductor device including: a DC/DC converter circuit, wherein the DC/DC converter circuit includes a transistor of a normally-off type, having a first drain electrode connected town input terminal and a first source electrode connected to an output terminal, which is formed in a first compound semiconductor substrate having a two-dimensional electron gas layer, and a transistor having a second drain electrode connected to the first source electrode and a grounded second source electrode.

A semiconductor device includes enhancement FinFET cells and depletion FinFET cells. The enhancement FinFET cells include first gate structures separating first semiconductor fins. The depletion FinFET cells include second gate structures separating second semiconductor fins. Between the first and second gate structures a connection structure separates the first semiconductor fins from the second semiconductor fins. The connection structure has a specific conductance which is higher than a specific conductance in the second semiconductor fins.

An electronic device can include a bidirectional HEMT. In an aspect, a packaged electronic device can include the bidirectional HEMT can be part of a die having a die substrate connection that is configured to be at a fixed voltage, electrically connected to drain/source or source/drain depending on current flow through the bidirectional HEMT, or electrically float. In another aspect, the electronic device can include Kelvin connections on both the drain/source and source/drain side of the circuit. In a further embodiment, a circuit can include the bidirectional HEMT, switch transistors, and diodes with breakdown voltages to limit voltage swings at the drain/source and source/drain of the switch transistors.