A MOSFET may be formed with a strain-inducing mismatch of lattice constants that improves carrier mobility. In exemplary embodiments a MOSFET includes a strain-inducing lattice constant mismatch that is not undermined by a recessing step. In some embodiments a source/drain pattern is grown without a recessing step, thereby avoiding problems associated with a recessing step. Alternatively, a recessing process may be performed in a way that does not expose top surfaces of a strain-relaxed buffer layer. A MOSFET device layer, such as a strain-relaxed buffer layer or a device isolation layer, is unaffected by a recessing step and, as a result, strain may be applied to a channel region without jeopardizing subsequent formation steps.

Vertical power MOSFETs having a super junction are devices capable of having a lower on resistance than other vertical power MOSFETs. Although they have the advantage of high-speed switching due to rapid depletion of an N type drift region at the time of turn off in switching operation, they are likely to cause ringing. A vertical power MOSFET having a super junction structure provided by the present invention has, in the surface region of a first conductivity type drift region under a gate electrode, an undergate heavily doped N type region having a depth shallower than that of a second conductivity type body region and having a concentration higher than that of the first conductivity type drift region.

In general, according to one embodiment, a semiconductor device includes, a first semiconductor region, a plurality of second semiconductor regions, a plurality of third semiconductor regions, a fourth semiconductor region, a fifth semiconductor region, and a gate electrode. The third semiconductor region includes a first portion and a second portion. The first portion is provided between the second semiconductor regions adjacent to each other. An amount of impurity of the second conductivity type in the first portion is greater than an amount of impurity of the first conductivity type in the second semiconductor region contiguous to the first portion. The second portion is arranged with a part of the first semiconductor region. An amount of impurity of the second conductivity type in the second portion is smaller than an amount of impurity of the first conductivity type in the part of the first semiconductor region.

A gate-all around fin double diffused metal oxide semiconductor (DMOS) devices and methods of manufacture are disclosed. The method includes forming a plurality of fin structures from a substrate. The method further includes forming a well of a first conductivity type and a second conductivity type within the substrate and corresponding fin structures of the plurality of fin structures. The method further includes forming a source contact on an exposed portion of a first fin structure. The method further comprises forming drain contacts on exposed portions of adjacent fin structures to the first fin structure. The method further includes forming a gate structure in a dielectric fill material about the first fin structure and extending over the well of the first conductivity type.

Embodiments include mixed complementary field effect and unipolar transistors and methods of forming the same. In an embodiment, a structure includes: a first semiconductor nanostructure; a second semiconductor nanostructure; a first isolation structure interposed between the first semiconductor nanostructure and the second semiconductor nanostructure; a first source/drain region extending laterally from an end of the first semiconductor nanostructure, the first source/drain region having a first conductivity type; a second source/drain region extending laterally from an end of the second semiconductor nanostructure, the second source/drain region having the first conductivity type, the second source/drain region aligned vertically with the first source/drain region; and a first gate structure surrounding the first semiconductor nanostructure and the second semiconductor nanostructure.

An embodiment relates to a n-type planar gate DMOSFET comprising a Silicon Carbide (SiC) substrate. The SiC substrate includes a N+ substrate, a N drift layer, a P-well region and a first N+ source region within each P-well region. A second N+ source region is formed between the P-well region and a source metal via a silicide layer. During third quadrant operation of the DMOSFET, the second N+ source region starts depleting when a source terminal is positively biased with respect to a drain terminal. The second N+ source region impacts turn-on voltage of body diode regions of the DMOSFET by establishing short-circuitry between the P-well region and the source metal when the second N+ source region is completely depleted.

A switching element includes a gate electrode and a source electrode disposed in each of trenches provided in a semiconductor substrate. A longitudinal direction of the trench is defined as a first direction, and the trenches are spaced from each other in a second direction intersecting the first direction. Each of the trenches extends in the first direction while being displaced in the second direction so as to satisfy that an inter-trench region between the adjacent trenches has narrow portions and wide portions alternately arranged in the first direction and alternately arranged in the second direction via the trenches. A source region is distributed across the narrow portion and the wide portion, and is in contact with the source electrode in the wide portion.

A vertical conduction MOSFET device includes a body of silicon carbide having a first conductivity type and a face. A metallization region extends on the face of the body. A body region of a second conductivity type extends in the body, from the face of the body, along a first direction parallel to the face and along a second direction transverse to the face. A source region of the first conductivity type extends towards the inside of the body region, from the face of the body. The source region has a first portion and a second portion. The first portion has a first doping level and extends in direct electrical contact with the metallization region. The second portion has a second doping level and extends in direct electrical contact with the first portion of the source region. The second doping level is lower than the first doping level.

A power semiconductor device having a barrier region is provided. A power unit cell of the power semiconductor device has at least two trenches that may both extend into the barrier region. The at least two trenches may both have a respective trench electrode coupled to a control terminal of the power semiconductor device. For example, the trench electrodes are structured to reduce the total gate charge of the power semiconductor device. The barrier region may be p-doped and vertically confined, i.e., in and against the extension direction, by the drift region. The barrier region can be electrically floating.

It is an object to provide the techniques capable of restraining avalanche breakdown at cells opposite to a corner portion of a gate pad. A MOSFET is provided with a corner cell, which is disposed in a region opposite to a corner portion of a gate pad in a planar view, and an internal cell, which is disposed in a region in the opposite side of the gate pad with respect to the corner cell. In a contour shape of the corner cell, a longest distance among distances each of which is shortest distance between a longest side and each of sides opposite to the longest side is equal to or less than two times of a length of one of equal sides or a short side of the internal cell.