The method includes prior to depositing a gate on a first vertical FET on a semiconductor substrate, depositing a first layer on the first vertical FET on the semiconductor substrate. The method further includes prior to depositing a gate on a second vertical FET on the semiconductor substrate, depositing a second layer on the second vertical FET on the semiconductor substrate. The method further includes etching the first layer on the first vertical FET to a lower height than the second layer on the second vertical FET. The method further includes depositing a gate material on both the first vertical FET and the second vertical FET. The method further includes etching the gate material on both the first vertical FET and the second vertical FET to a co-planar height.

The present invention relates generally to integrated circuits and more particularly, to a structure and method of forming a hybrid circuit including a tunnel field-effect transistor (TFET) and a conventional field effect transistor (FET). Embodiments of the present invention include a hybrid amplifier which features a TFET common-source feeding a common-gate conventional FET (e.g. a MOSFET). A TFET gate may be electrically isolated from an output from a conventional FET. Thus, a high impedance input may be received by a TFET with a high-isolation output (i.e. low capacitance) at a conventional FET. A hybrid circuit amplifier including a TFET and a conventional FET may have a very high input impedance and a low miller capacitance.

A semiconductor structure includes a plurality of semiconductor fins located on a semiconductor substrate, in which each of the semiconductor fins comprises a sequential stack of a buffered layer including a III-V semiconductor material and a channel layer including a III-V semiconductor material. The semiconductor structure further includes a gap filler material surrounding the semiconductor fins and including a plurality of trenches therein. The released portions of the channel layers of the semiconductor fins located in the trenches constitute nanowire channels of the semiconductor structure, and opposing end portions of the channel layers of the semiconductor fins located outside of the trenches constitute a source region and a drain region of the semiconductor structure, respectively. In addition, the semiconductor structure further includes a plurality of gates structures located within the trenches that surround the nanowire channels in a gate all around configuration.

Various embodiments disclose a method for fabricating a semiconductor structure including a plurality of vertical transistors each having different threshold voltages. In one embodiment the method includes forming a structure having at least a substrate, a source contact layer on the substrate, a first spacer layer on the source contact layer, a replacement gate on the first spacer layer, a second spacer layer on the replacement gate, and an insulating layer on the second spacer layer. A first trench is formed in a first region of the structure. A first channel layer having a first doping concentration is epitaxially grown in the first trench. A second trench is formed in a second region of the structure. A second channel layer having a second doping concentration is epitaxially grown in the second trench. The second doping concentration is different from the first doping concentration.

Various embodiments disclose a method for fabricating a semiconductor structure including a plurality of vertical transistors each having different threshold voltages. In one embodiment the method includes forming a structure having at least a substrate, a source contact layer on the substrate, a first spacer layer on the source contact layer, a replacement gate on the first spacer layer, a second spacer layer on the replacement gate, and an insulating layer on the second spacer layer. A first trench is formed in a first region of the structure. A first channel layer having a first doping concentration is epitaxially grown in the first trench. A second trench is formed in a second region of the structure. A second channel layer having a second doping concentration is epitaxially grown in the second trench. The second doping concentration is different from the first doping concentration.

Various embodiments disclose a method for fabricating a semiconductor structure. In one embodiment, the method includes forming a masking layer over at least a first portion of a source contact layer formed on a substrate. At least a second portion of the source contact layer is recessed below the first portion of the source contact layer. The mask layer is removed and a first spacer layer, a replacement gate on the first spacer layer, a second spacer layer on the replacement gate, and an insulating layer on the second spacer layer are formed. First and second trenches are then formed. A first channel layer is epitaxially grown within the first trench. A second channel layer is epitaxially grown within the second trench. A length of the second channel layer is greater than a length of the first channel layer.

A vertical semiconductor device (e.g. a vertical power device, an IGBT device, a vertical bipolar transistor, a UMOS device or a GTO thyristor) is formed with an active semiconductor region, within which a plurality of semiconductor structures have been fabricated to form an active device, and below which at least a portion of a substrate material has been removed to isolate the active device, to expose at least one of the semiconductor structures for bottom side electrical connection and to enhance thermal dissipation. At least one of the semiconductor structures is preferably contacted by an electrode at the bottom side of the active semiconductor region.

Methods of forming a memory device having an array portion including a plurality of array transistors and a periphery region including peripheral circuit transistor structures of the memory device, where an upper surface of the periphery region and an upper surface of the array portion are planar (or nearly planar) after formation of the peripheral circuit transistor structures and a plurality of memory cells (formed over the array transistors). The method includes forming the peripheral circuit transistor structures in the periphery region, forming the plurality of array transistors in the array portion and forming a plurality of memory cells over respective vertical transistors. Structures formed by the method have planar upper surfaces of the periphery and array regions.

An opening extending through a gate insulating layer and a gate conductor layer is formed in the circumferential portion of a Si pillar at an intermediate height of the Si pillar. A laminated structure including two sets each including a Ni film, a poly-Si layer containing donor or acceptor impurity atoms, and a SiO.sub.2 layer is formed so as to surround the opening. A heat treatment is carried out to form silicide from the poly-Si layers and this silicide formation causes the resultant NiSi layers to protrude and come into contact with the side surface of the Si pillar. The donor or acceptor impurity atoms diffuse from the NiSi layers into the Si pillar to thereby form an N.sup.+ region and a P.sup.+ region serving as a source or a drain of SGTs.

An array of gated devices includes a plurality of gated devices arranged in rows and columns and individually including an elevationally inner region, a mid region elevationally outward of the inner region, and an elevationally outer region elevationally outward of the mid region. A plurality of access lines are individually laterally proximate the mid regions along individual of the rows. A plurality of data/sense lines are individually elevationally outward of the access lines and electrically coupled to the outer regions along individual of the columns. A plurality of metal lines individually extends along and between immediately adjacent of the rows elevationally inward of the access lines. The individual metal lines are directly against and electrically coupled to sidewalls of the inner regions of each of immediately adjacent of the rows. The metal lines are electrically isolated from the data/sense lines. Other arrays of gated devices and methods of forming arrays of gated devices are disclosed.