A MOS transistor, in particular a vertical channel transistor, includes a semiconductor body housing a body region, a source region, a drain electrode and gate electrodes. The gate electrodes extend in corresponding recesses which are symmetrical with respect to an axis of symmetry of the semiconductor body. The transistor also has spacers which are also symmetrical with respect to the axis of symmetry. A source electrode extends in electrical contact with the source region at a surface portion of the semiconductor body surrounded by the spacers and is in particular adjacent to the spacers. During manufacture the spacers are used to form in an auto-aligning way the source electrode which is symmetrical with respect to the axis of symmetry and equidistant from the gate electrodes.

A semiconductor device includes a contact opening extending through a source region and a body region of the device. An electrically insulative spacer lines sidewalls of the semiconductor substrate formed by the contact opening, and is recessed along the sidewalls such that at least part of the source region or body region is uncovered by the electrically insulative spacer. A body contact plug is in the contact opening. A first body contact region formed adjacent a bottom of the contact opening adjoins the body contact plug at the bottom of the contact opening. A second body contact region formed in the part of the source region or body region uncovered by the electrically insulative spacer adjoins the body contact plug along the part of the source region or body region uncovered by the electrically insulative spacer.

Provided is a method of forming a trench gate MOSFET. A hard mask layer is formed on a substrate. The substrate is partially removed by using the hard mask layer as a mask, so as to form a trench in the substrate. A first insulating layer and a first conductive layer are formed in the lower portion of the trench. A sacrificial layer is formed on the side surface of the upper portion of the trench, and the sacrificial layer is connected to the hard mask layer. An interlayer insulating layer is formed on the first conductive layer by a thermal oxidation process when the sacrificial layer and the hard mask layer are present. A second insulating layer and a second conductive layer are formed in the upper portion of the trench. A trench gate MOSFET is further provided.

Provided is a method of forming a trench gate MOSFET. A hard mask layer is formed on a substrate. The substrate is partially removed by using the hard mask layer as a mask, so as to form a trench in the substrate. A first insulating layer and a first conductive layer are formed in the lower portion of the trench. A sacrificial layer is formed on the side surface of the upper portion of the trench, and the sacrificial layer is connected to the hard mask layer. An interlayer insulating layer is formed on the first conductive layer by a thermal oxidation process when the sacrificial layer and the hard mask layer are present. A second insulating layer and a second conductive layer are formed in the upper portion of the trench. A trench gate MOSFET is further provided.

An embodiment relates to a method comprising obtaining a SiC substrate comprising a N+ substrate and a N− drift layer; depositing a first hard mask layer on the SiC substrate and patterning the first hard mask layer; performing a p-type implant to form a p-well region; depositing a second hard mask layer on top of the first hard mask layer; performing an etch back of at least the second hard mask layer to form a sidewall spacer; implanting N type ions to form a N+ source region that is self-aligned; and forming a MOSFET.

A MOS transistor, in particular a vertical channel transistor, includes a semiconductor body housing a body region, a source region, a drain electrode and gate electrodes. The gate electrodes extend in corresponding recesses which are symmetrical with respect to an axis of symmetry of the semiconductor body. The transistor also has spacers which are also symmetrical with respect to the axis of symmetry. A source electrode extends in electrical contact with the source region at a surface portion of the semiconductor body surrounded by the spacers and is in particular adjacent to the spacers. During manufacture the spacers are used to form in an auto-aligning way the source electrode which is symmetrical with respect to the axis of symmetry and equidistant from the gate electrodes.

A semiconductor power device and a manufacturing method thereof are provided. In the manufacturing method, before the self-aligned silicide process is performed, a gate stacked structure and a spacer are formed on a semiconductor layer having a body region and a source region. The spacer defines a portion of the source region for forming a silicide layer. Subsequently, the self-aligned silicide process is performed with the gate stacked structure and the spacer functioning as a mask to form the silicide layer at the defined portion of the source region. Thereafter, an interconnection structure including an interlayer dielectric layer and a source conductive layer is formed on the semiconductor layer. The source conductive layer is electrically connected to the source region. The silicide layer extends toward the gate stacked structure from a position under the source conductive layer to another position under the interlayer dielectric layer.

A MOSFET includes a semiconductor body having a first side, a drift region, a body region forming a first pn-junction with the drift region, a source region forming a second pn-junction with the body region, in a vertical cross-section, a dielectric structure on the first side and having an upper side; a first gate electrode, a second gate electrode, a contact trench between the first and second gate electrodes, extending through the dielectric structure to the source region, in a horizontal direction a width of the contact trench has, in a first plane, a first value, and, in a second plane, a second value which is at most about 2.5 times the first value, and a first contact structure arranged on the dielectric structure having a through contact portion arranged in the contact trench, and in Ohmic contact with the source region.

A semiconductor device includes a trench extending into a first main surface of a semiconductor substrate, and a gate electrode and a gate dielectric in the trench. The gate dielectric separates the gate electrode from the semiconductor substrate. A first region having a first conductivity type is formed in the semiconductor substrate at the first surface adjacent the trench. A second region having a second conductivity type is formed in the semiconductor substrate below the first region adjacent the trench. A third region having the first conductivity type is formed in the semiconductor substrate below the second region adjacent the trench. A contact opening in the semiconductor substrate extends into the second region. An electrically insulative spacer is disposed on sidewalls of the semiconductor substrate formed by the contact opening, and an electrically conductive material in the contact opening adjoins the electrically insulative spacer on the sidewalls.

First trenches extend from a process surface into a semiconductor layer. An alignment layer with mask pits in a with respect to the process surface vertical projection of the first trenches is formed on the process surface. Sidewalls of the mask pits have a smaller tilt angle with respect to the process surface than sidewalls of the first trenches. The mask pits are filled with an auxiliary material. A gate trench for a gate structure is formed in a mesa section of the semiconductor layer between the first trenches, wherein the auxiliary material is used as an etch mask.