A semiconductor device is provided including a transistor cell in a semiconductor substrate having a first main surface. The transistor cell includes a gate electrode in a gate trench in the first main surface adjacent to a body region. A longitudinal axis of the gate trench extends in a first direction parallel to the first main surface. A source region, a body region and a drain region are disposed along the first direction. A source contact comprises a first source contact portion and a second source contact portion. The second source contact portion is disposed at a second main surface of the semiconductor substrate. The first source contact portion includes a source conductive material in direct contact with the source region and a portion of the semiconductor substrate arranged between the source conductive material and the second source contact portion.

A planar gate power MOSFET includes a substrate having a semiconductor surface doped a first conductivity type, a plurality of transistor cells (cells) including a first cell and at least a second cell each having a gate stack over a body region. A trench has an aspect ratio of >3 extending down from a top side of the semiconductor surface between the gate stacks providing a source contact (SCT) from a source doped a second conductivity type to the substrate. A field plate (FP) is over the gate stacks that provides a liner for the trench. The trench has a refractory metal or platinum-group metal (PGM) metal filler within. A drain doped the second conductivity type is in the semiconductor surface on a side of the gate stacks opposite the trench.

A semiconductor device includes a transistor in a semiconductor body having a first main surface. The transistor includes: a source contact electrically connected to a source region; a drain contact electrically connected to a drain region; a gate electrode at the channel region, the channel region and a drift zone disposed along a first direction between the source and drain regions, the first direction being parallel to the first main surface, the channel region patterned into a ridge by adjacent gate trenches formed in the first main surface, the adjacent gate trenches spaced apart in a second direction perpendicular to the first direction, a longitudinal axis of the ridge extending in the first direction and a longitudinal axis of the gate trenches extending in the first direction; and at least one of the source and drain contacts being adjacent to a second main surface opposite the first main surface.

A laterally diffused metal oxide semiconductor (LDMOS) transistor structure with improved unclamped inductive switching immunity. The LDMOS includes a substrate and an adjacent epitaxial layer both of a first conductivity type. A gate structure is above the epitaxial layer. A drain region and a source region, both of a second conductivity type, are within the epitaxial layer. A channel is formed between the source and drain region and arranged below the gate structure. A body structure of the first conductivity type is at least partially formed under the gate structure and extends laterally under the source region, wherein the epitaxial layer is less doped than the body structure. A conductive trench-like feed-through element passes through the epitaxial layer and contacts the substrate and the source region. The LDMOS includes a tub region of the first conductivity type formed under the source region, and adjacent laterally to and in contact with said body structure and said trench-like feed-through element.

A semiconductor device includes: a semiconductor chip having a first main surface and a second main surface opposite to the first main surface; a first drain region of first conductivity type formed in a surface layer portion of the first main surface; a back gate region of second conductivity type spaced apart from the first drain region in the surface layer portion of the first main surface; a source region of the first conductivity type spaced inward from a peripheral edge of the back gate region in a surface layer portion of the back gate region; a back gate contact region of the second conductivity type electrically isolated from the source region in the surface layer portion of the back gate region; and a gate electrode facing a channel region formed in the back gate region between the peripheral edge of the back gate region and the source region.

The present disclosure provides a semiconductor device including a diode. The semiconductor device includes: a semiconductor substrate; an n-type diffusion region selectively formed in a surface layer portion of a p-type epitaxial layer; an n-type buried layer sandwiched between the semiconductor substrate and the n-type diffusion region and having an impurity concentration greater than that of the n-type diffusion region; a p-type anode contact region formed in a surface layer portion of a first main surface of the semiconductor substrate; an n-type first cathode contact region formed in a surface layer portion of the n-type diffusion region and in a surface layer portion of the first main surface; a p-type well region extending along a depth direction from the first main surface outside the first cathode contact region to reach the n-type buried layer, dividing the n-type diffusion region along a direction along the first main surface.

A planar gate power MOSFET includes a substrate having a semiconductor surface doped a first conductivity type, a plurality of transistor cells (cells) including a first cell and at least a second cell each having a gate stack over a body region. A trench has an aspect ratio of >3 extending down from a top side of the semiconductor surface between the gate stacks providing a source contact (SCT) from a source doped a second conductivity type to the substrate. A field plate (FP) is over the gate stacks that provides a liner for the trench. The trench has a refractory metal or platinum-group metal (PGM) metal filler within. A drain doped the second conductivity type is in the semiconductor surface on a side of the gate stacks opposite the trench.

A quasi-lateral diffusion transistor is formed in a semiconductor-on-insulator (SOI) wafer by forming a gate region, a body region, a drift region, and a source region and bonding a handle wafer to the SOI wafer at a first side (e.g., top side) of the SOI wafer; and removing a semiconductor substrate of the SOI wafer, forming a hole in a buried insulator layer of the SOI wafer, and forming a drain region for the transistor at a second side (e.g., bottom side) of the SOI wafer. The body region and the drift region physically contact the buried insulator layer. The drain region is formed in a bottom portion of the drift region exposed by the hole and is laterally offset from the source region. In operation of the quasi-lateral diffusion transistor, a current flow direction through the semiconductor layer is diagonal between the source region and the drain region.

A semiconductor device comprises a field effect transistor in a semiconductor substrate having a first main surface. The field effect transistor comprises a source region, a drain region, a body region, and a gate electrode at the body region. The gate electrode is configured to control a conductivity of a channel formed in the body region, and the gate electrode is disposed in gate trenches. The body region is disposed along a first direction between the source region and the drain region, the first direction being parallel to the first main surface. The body region has a shape of a ridge extending along the first direction, the body region being adjacent to the source region and the drain region. The semiconductor device further comprises a source contact and a body contact, the source contact being electrically connected to a source terminal, the body contact being electrically connected to the source contact and to the body region.

A transistor cell includes a drift region, a source region, a body region, and a drain region that is laterally spaced apart from the source region. A gate electrode is adjacent the body region. A field electrode is arranged in the drift region. A source electrode is connected to the source region and the body region, and a drain electrode is connected to the drain region. An avalanche bypass structure is coupled between the source electrode and the drain electrode and includes a first semiconductor layer of the first doping type, a second semiconductor layer of the first doping type, and a pn-junction arranged between the first semiconductor layer and the source electrode. The second semiconductor layer has a higher doping concentration than the first semiconductor layer and is arranged between the second semiconductor layer and the drift region. The drain electrode is electrically connected to the second semiconductor layer.