Transistors having partially recessed gates are constructed on silicon-on-insulator (SOI) semiconductor wafers provided with a buried oxide layer (BOX), for example, FD-SOI and UTBB devices. An epitaxially grown channel region relaxes constraints on the design of doped source and drain profiles. Formation of a partially recessed gate and raised epitaxial source and drain regions allow further improvements in transistor performance and reduction of short channel effects such as drain induced barrier lowering (DIBL) and control of a characteristic subthreshold slope. Gate recess can be varied to place the channel at different depths relative to the dopant profile, assisted by advanced process control. The partially recessed gate has an associated high-k gate dielectric that is initially formed in contact with three sides of the gate. Subsequent removal of the high-k sidewalls and substitution of a lower-k silicon nitride encapsulant lowers capacitance between the gate and the source and drain regions.

A vertical FinFET includes a semiconductor fin formed over a semiconductor substrate. A self-aligned first source/drain contact is electrically separated from a second source/drain contact by a sidewall spacer that is formed over an endwall of the fin. The sidewall spacer, which comprises a dielectric material, allows the self-aligned first source/drain contact to be located in close proximity to an endwall of the fin and the associated second source/drain contact without risk of an electrical short between the adjacent contacts.

A semiconductor device having a high-k gate dielectric, and a method of manufacture, is provided. A gate dielectric layer is formed over a substrate. An interfacial layer may be interposed between the gate dielectric layer and the substrate. A barrier layer, such as a TiN layer, having a higher concentration of nitrogen along an interface between the barrier layer and the gate dielectric layer is formed. The barrier layer may be formed by depositing, for example, a TiN layer and performing a nitridation process on the TiN layer to increase the concentration of nitrogen along an interface between the barrier layer and the gate dielectric layer. A gate electrode is formed over the barrier layer.

A semiconductor device includes a semiconductor substrate having a gate trench including of an upper trench and a lower trench. The upper trench is wider than the lower trench. A gate is embedded in the gate trench. The gate includes an upper portion and a lower portion. A first gate dielectric layer is between the upper portion and a sidewall of the upper trench. The first gate dielectric layer has a first thickness. A second gate dielectric layer is between the lower portion and a sidewall of the lower trench and between the lower portion and a bottom surface of the lower trench. The second gate dielectric layer has a second thickness that is smaller than the first thickness.

A vertical FinFET includes a semiconductor fin formed over a semiconductor substrate. A self-aligned first source/drain contact is electrically separated from a second source/drain contact by a sidewall spacer that is formed over an endwall of the fin. The sidewall spacer, which comprises a dielectric material, allows the self-aligned first source/drain contact to be located in close proximity to an endwall of the fin and the associated second source/drain contact without risk of an electrical short between the adjacent contacts.

A semiconductor device includes a semiconductor substrate having a gate trench including an upper trench and a lower trench. The upper trench is wider than the lower trench. A gate is embedded in the gate trench. The gate includes an upper portion and a lower portion. A first gate dielectric layer is between the upper portion and a sidewall of the upper trench. The first gate dielectric layer has a first thickness. A second gate dielectric layer is between the lower portion and a sidewall of the lower trench and between the lower portion and a bottom surface of the lower trench. The second gate dielectric layer has a second thickness that is smaller than the first thickness.

A method for forming a semiconductor structure includes forming a strained silicon germanium layer on top of a substrate. At least one patterned hard mask layer is formed on and in contact with at least a first portion of the strained silicon germanium layer. At least a first exposed portion and a second exposed portion of the strained silicon germanium layer are oxidized. The oxidizing process forms a first oxide region and a second oxide region within the first and second exposed portions, respectively, of the strained silicon germanium.

A vertical FinFET includes a semiconductor fin formed over a semiconductor substrate. A self-aligned first source/drain contact is electrically separated from a second source/drain contact by a spacer layer that is formed over an endwall of the fin. The spacer layer, which comprises a dielectric material, allows the self-aligned first source/drain contact to be located in close proximity to an endwall of the fin and the associated second source/drain contact without risk of an electrical short between the adjacent contacts.

A FinFET device and a method of forming the same are provided. A method includes forming a patterned mask stack over a substrate, features of the patterned mask stack protecting the substrate having a uniform width. Unprotected portions of the substrate exposed by the patterned mask stack are removed to form a plurality of recesses in the substrate, unremoved portions of the substrate interposed between adjacent recesses forming a plurality of fins. Portions of the plurality of fins are removed, a width of a first fin of the plurality of fins being less than a width of a second fin of the plurality of fins.

Gate contact structures disposed over active portions of gates and methods of forming such gate contact structures are described. For example, a semiconductor structure includes a substrate having an active region and an isolation region. A gate structure has a portion disposed above the active region and a portion disposed above the isolation region of the substrate. Source and drain regions are disposed in the active region of the substrate, on either side of the portion of the gate structure disposed above the active region. A gate contact structure is disposed on the portion of the gate structure disposed above the active region of the substrate.