A method of fabricating a vertical field effect transistor including forming a first recess in a substrate; epitaxially growing a first drain from the first bottom surface of the first recess; epitaxially growing a second drain from the second bottom surface of a second recess formed in the substrate; growing a channel material epitaxially on the first drain and the second drain; forming troughs in the channel material to form one or more fin channels on the first drain and one or more fin channels on the second drain, wherein the troughs over the first drain extend to the surface of the first drain, and the troughs over the second drain extend to the surface of the second drain; forming a gate structure on each of the one or more fin channels; and growing sources on each of the fin channels associated with the first and second drains.

Transistor and methods of forming the same include forming a channel fin on a bottom source/drain region. A dielectric fill is formed around the channel fin with a gap in an area directly above the channel fin that has a width greater than a width of the channel fin. Spacers are formed in the gap. The dielectric fill is etched away. A gate stack is formed on sidewalls of the channel fin directly underneath the spacers.

Formation of a bottom junction in vertical FET devices may include, for instance, providing an intermediate semiconductor structure comprising a semiconductor substrate, a fin disposed on the semiconductor substrate. The fin has a top surface, spaced-apart vertical sides. A mask is disposed over the top surface of the fin, and at least one is disposed over the vertical sides of the fin. Portions of the substrate are removed to define spaced-apart recesses each extending below a respective one of the spacers. Semiconductor material is grown, such as epitaxially grown, in the recesses.

A method of manufacturing a semiconductor device includes forming a first trench in a semiconductor substrate from a first side, forming a semiconductor layer adjoining the semiconductor substrate at the first side, the semiconductor layer capping the first trench at the first side, and forming a contact at a second side of the semiconductor substrate opposite to the first side.

An SGT is produced by forming a first insulating film around a fin-shaped semiconductor layer, forming a pillar-shaped semiconductor layer in an upper portion of the fin-shaped layer, forming a second insulating film, a polysilicon gate electrode covering the second insulating film, and a polysilicon gate line, forming a diffusion layer in an upper portion of the fin-shaped layer and a lower portion of the pillar-shaped layer, forming a metal-semiconductor compound in an upper portion of the diffusion layer in the fin-shaped layer, depositing an interlayer insulating film, exposing and etching the polysilicon gate electrode and gate line, depositing a first metal, forming a metal gate electrode and a metal gate line, and forming a third metal sidewall on an upper side wall of the pillar-shaped layer. The third metal sidewall is connected to an upper surface of the pillar-shaped layer.

A semiconductor device includes a pillar-shaped semiconductor layer and a first gate insulating film around the pillar-shaped semiconductor layer. A metal gate electrode is around the first gate insulating film and a metal gate line is connected to the gate electrode. A second gate insulating film is around a sidewall of an upper portion of the pillar-shaped semiconductor layer and a first contact made of a second metal surrounds the second gate insulating film. An upper portion of the first contact is electrically connected to an upper portion of the pillar-shaped semiconductor layer, and a third contact resides on the metal gate line. A lower portion of the third contact is made of the second metal.

The disclosed technology generally relates to semiconductor devices, and more particularly to transistor devices comprising multiple channels. In one aspect, a method of fabricating a transistor device comprises forming on the substrate a plurality of vertically repeating layer stacks each comprising a first layer, a second layer and a third layer stacked in a predetermined order, wherein each of the first, second and third layers is formed of silicon, silicon germanium or germanium and has a different germanium concentration compared to the other two of the first, second and third layers. The method additionally includes selectively removing the first layer with respect to the second and third layers from each of the layer stacks, such that a gap interposed between the second layer and the third layer is formed in each of the layer stacks. The method further includes selectively removing the second layer from each of the layer stacks with respect to the third layer, wherein removing the second layer comprises at least partially removing the second layer through the gap, thereby defining the channels comprising a plurality of vertically arranged third layers.

In one aspect, methods of silicidation and germanidation are provided. In some embodiments, methods for forming metal silicide can include forming a non-oxide interface, such as germanium or solid antimony, over exposed silicon regions of a substrate. Metal oxide is formed over the interface layer. Annealing and reducing causes metal from the metal oxide to react with the underlying silicon and form metal silicide. Additionally, metal germanide can be formed by reduction of metal oxide over germanium, whether or not any underlying silicon is also silicided. In other embodiments, nickel is deposited directly and an interface layer is not used. In another aspect, methods of depositing nickel thin films by vapor phase deposition processes are provided. In some embodiments, nickel thin films are deposited by ALD.

A vertical fin field-effect-transistor and a method for fabricating the same. The vertical fin field-effect-transistor includes a substrate, a first source/drain layer including a plurality of pillar structures, and a plurality of fins disposed on and in contact with the plurality of pillar structures. A doped layer epitaxially grown from the first source/drain layer is in contact with the plurality of fins and the plurality of pillar structures. A gate structure is disposed in contact with two or more fins in the plurality of fins. The gate structure includes a dielectric layer and a gate layer. A second source/drain layer is disposed on the gate structure. The method includes epitaxially growing a doped layer in contact with a plurality of fins and a plurality of pillar structures. A gate structure is formed in contact with two or more fins. A second source/drain layer is formed on the gate structure.

A semiconductor device includes a pillar-shaped semiconductor having an impurity concentration of 10.sup.17 cm.sup.3 or less. A first insulator surrounds the pillar-shaped semiconductor and a first metal surrounds a portion of the first insulator at a first end of the pillar-shaped semiconductor. A second metal surrounds a portion of the first insulator at a second end of the pillar-shaped semiconductor, and a third metal surrounds a portion of the first insulator in a region between the first and second metals. The first metal and the second metal are electrically insulated from the third metal. Source/drain regions are defined in the pillar-shaped semiconductor due to a work function difference between the pillar-shaped semiconductor and the first and second metals.