The present disclosure relates to methods of manufacturing Ohmic contacts on a silicon carbide (SiC) substrate including providing a 4H—SiC or 6H—SiC substrate, implanting dopants into a surface region of the 4H—SiC or 6H—SiC substrate, annealing the implanted surface regions to form a 3C—SiC layer, and depositing a metal layer on the 3C—SiC layer. An implanting sequence of the implantation of dopants includes a plurality of plasma deposition acts with implantation energy levels including at least two different implantation energy levels. The implantation energy levels and one or more implantation doses of the plurality of plasma deposition acts are selected to form a 3C—SiC layer in the surface region of the 4H—SiC or 6H—SiC substrate during the annealing act. A method of manufacturing a semiconductor device having a structure including at least three layers including a 4H—SiC or 6H—SiC layer, a 3C—SiC layer, and a metal layer, by applying one or more of the techniques described herein, and semiconductor devices obtained with one or more of the techniques described herein are described.

A method of n-type doping a carbon nanotube includes the following steps: providing a single carbon nanotube; providing a film-like structure, wherein the film-like structure is a molybdenum disulfide film or a tungsten disulfide film; and converting at least one portion of the carbon nanotube from a p-type to an n-type by covering the carbon nanotube with the film-like structure.

A semiconductor device includes a semiconductor layer structure of a wide band-gap semiconductor material. The semiconductor layer structure includes a drift region having a first conductivity type and a well region having a second conductivity type. A plurality of segmented gate trenches extend in a first direction in the semiconductor layer structure. The segmented gate trenches include respective gate trench segments that are spaced apart from each other in the first direction with intervening regions of the semiconductor layer structure therebetween. Related devices and fabrication methods are also discussed.

A method comprising the irradiation of a wafer by an ion beam that passes through an implantation filter. The wafer is heated to a temperature of more than 200° C. The wafer is a semiconductor wafer including SiC, and the ion beam includes aluminum ions.

An SiC semiconductor device includes an SiC semiconductor layer including an SiC monocrystal that is constituted of a hexagonal crystal and having a first main surface as a device surface facing a c-plane of the SiC monocrystal and has an off angle inclined with respect to the c-plane, a second main surface at a side opposite to the first main surface, and a side surface facing an a-plane of the SiC monocrystal and has an angle less than the off angle with respect to a normal to the first main surface when the normal is 0°.

In a silicon carbide semiconductor device in which a contact electrode is formed on a single-crystal silicon carbide semiconductor substrate, a barrier metal (titanium nitride layer) covers an interlayer insulating film in a region other than a contact hole, and a contact electrode of a predetermined electrode material is formed only in a region on the silicon carbide semiconductor substrate in the contact hole opened in the interlayer insulating film on the silicon carbide semiconductor substrate. A top of the barrier metal is covered by a metal electrode (wiring layer) and no nickel metal aggregates are present between the barrier metal and the metal electrode.

An electrode structure with an alloy interface is provided. In one aspect, a method of forming a contact structure includes: patterning a via in a first dielectric layer; depositing a barrier layer onto the first dielectric layer, lining the via; depositing and polishing a first metal layer (Element A) into the via to form a contact in the via; depositing a second metal layer (Element B) onto the contact in the via; annealing the first and second metal layers under conditions sufficient to form an alloy AB; depositing a third metal layer onto the second metal layer; patterning the second and third metal layers into a pedestal stack over the contact to form an electrode over the contact, wherein the alloy AB is present at an interface of the electrode and the contact; and depositing a second dielectric that surrounds the pedestal stack. A contact structure is also provided.

A semiconductor structure is provided. The semiconductor structure includes an insulator layer, first and second field-effect transistor devices, an isolation field-effect transistor device, front-side gate and back-side gate contacts. Each of the first and second field-effect transistor devices and the isolation field-effect transistor device includes a fin structure and first and second epitaxial source/drain structures. The fin structure includes channel layers and a gate structure that is wrapped around the channel layers. The first and second epitaxial source/drain structures are connected to opposite sides of the channel layers. The isolation field-effect transistor device is kept in the off-state. The front-side gate contact is formed on the first field-effect transistor device and electrically connected to the gate structure of the first field-effect transistor device. The back-side gate contact is formed passing through the insulator layer and electrically connected to the gate structure of the isolation field-effect transistor device.

A method of manufacturing a silicon carbide semiconductor device includes formation of an electrode and formation of a gate wiring. The electrode is formed to be electrically connected to a base layer and an impurity region included in a semiconductor substrate through a first contact hole. The gate wiring is formed to be electrically connected to a connection wiring through a second contact hole, and is made of material capable of deoxidizing an oxide film. The oxide film is removed by deoxidizing the oxide film formed on the connection wiring to remove the oxygen from the oxide film into the gate wiring through heating treatment for the gate wiring in the formation of the gate wiring or after the formation of the gate wiring.

A power device includes a silicon carbide substrate. A gate is provided on a first side of the silicon carbide substrate. A graded channel includes a first region having a first dopant concentration and a second region having a second dopant concentration, the second dopant concentration being greater than the first dopant concentration.