A bonded wafer structure having a handle wafer, a device wafer, and an interface region with an abrupt transition between the conductivity profile of the device wafer and the handle wafer is used for making semiconductor devices. The improved doping profile of the bonded wafer structure is well suited for use in the manufacture of integrated circuits. The bonded wafer structure is especially suited for making radiation-hardened integrated circuits.

A semiconductor device fabrication process includes forming a fin and a plurality of gates upon a semiconductor substrate, forming sacrificial spacers upon opposing gate sidewalls, forming a mask upon an upper surface of the fin between neighboring gates, removing the sacrificial spacers, recessing a plurality of regions of the fin to create a dummy fin and fin segments, removing the mask, and epitaxially merging the dummy fin and fin segments. The fins may be partially recessed prior to forming the sacrificial spacers. The device may include the substrate, gates, fin segments each associated with a particular gate, the dummy fin between a fin segment pair separated by the wider pitch, and merged epitaxy connecting the dummy fin and the fin segment pair. The dummy fin may serve as a filler between the fin segment pair and may add epitaxial growth planes to allow for epitaxial merging within the wider pitch.

An integrated semiconductor transistor chip for use in a buck converter includes a high side transistor formed on the chip and comprising a laterally diffused metal oxide semiconductor (LDMOS) transistor and a low side transistor formed on the chip and comprising a source down metal oxide semiconductor field effect transistor (MOSFET). The chip also includes a substrate of the chip for use as a source for the low side transistor and an n-doped well for isolation of the high side transistor from the source of the low side transistor.

A high voltage transistor includes a substrate, a well which is disposed within the substrate, a gate disposed on the well, a gate dielectric layer disposed between the well and the gate, two drift regions respectively disposed in the well at two sides of the gate, two source/drain regions respectively disposed within each drift region, wherein a width of the gate dielectric layer is smaller than a width of the source/drain region, and two isolation elements respectively disposed within each drift region

A semiconductor device has a substrate and gate structure over the substrate. A source region is formed in the substrate adjacent to the gate structure. A drain region in the substrate adjacent to the gate structure opposite the source region. An interconnect structure is formed over the substrate by forming a conductive plane electrically connected to the source region, and forming a conductive layer within openings of the conductive plane and electrically connected to the drain region. The interconnect structure can be formed as stacked conductive layers laid out in alternating strips. The conductive plane extends under a gate terminal of the semiconductor device. An insulating layer is formed over the substrate and a field plate is formed in the insulating layer. The field plate is electrically connected the source terminal. A stress relief layer is formed over a surface of the substrate opposite the gate structure.

A MOS transistor structure for matched operation in weak-inversion or sub-threshold range (e.g. input-pair of operational amplifier, comparator, and/or current-mirror) is disclosed. The transistor structure may include a well region of any impurity type in a substrate (SOI is included). The well-region can even be represented by the substrate itself. At least one transistor is located in the well region, whereby the active channel-region of the transistor is independent from lateral isolation interfaces between GOX (gate oxide) and FOX (field oxide; including STI-shallow trench isolation).

A semiconductor structure and a method for forming the same are provided. The semiconductor structure comprises a first doped region, a second doped region, a doped strip and a top doped region. The first doped region has a first type conductivity. The second doped region is formed in the first doped region and has a second type conductivity opposite to the first type conductivity. The doped strip is formed in the first doped region and has the second type conductivity. The top doped region is formed in the doped strip and has the first type conductivity. The top doped region has a first sidewall and a second sidewall opposite to the first sidewall. The doped strip is extended beyond the first sidewall or the second sidewall.

A lateral double diffused metal-oxide-semiconductor device includes: an epitaxial semiconductor layer disposed over a semiconductor substrate; a gate dielectric layer disposed over the epitaxial semiconductor layer; a gate stack disposed over the gate dielectric layer; a first doped region disposed in the epitaxial semiconductor layer from a first side of the gate stack; a second doped region disposed in the epitaxial semiconductor layer from a second side of the gate stack; a third doped region disposed in the first doping region; a fourth doped region disposed in the second doped region; an insulating layer covering the third doped region, the gate dielectric layer, and the gate stack; a conductive contact disposed in the insulating layer, the third doped region, the first doped region and the epitaxial semiconductor layer; and a fifth doped region disposed in the epitaxial semiconductor layer under the conductive contact.

A method of evaluating a semiconductor device having an insulated gate formed of a metal-oxide film semiconductor. The semiconductor device has a high potential side and a low potential side, and a threshold voltage that is a minimum voltage for forming a conducting path between the high and low potential sides. The method includes determining a variation of the threshold voltage at turn-on of the semiconductor device by continuously applying an alternating current (AC) voltage to the gate of the semiconductor device, a maximum voltage of the AC voltage being equal to or higher than the threshold voltage of the semiconductor device.

An ESD protection semiconductor device includes a substrate, a gate set formed on the substrate, a source region and a drain region formed in the substrate respectively at two sides of the gate set, and at least a first doped region formed in the drain region. The source region and the drain region include a first conductivity type, and the first doped region includes a second conductivity type. The first conductivity type and the second conductivity type are complementary to each other. The first doped region is electrically connected to a ground potential.