Abstract: Ge and III-V channel semiconductor devices having maximized compliance and free surface relaxation and methods of fabricating such Ge and III-V channel semiconductor devices are described. For example, a semiconductor device includes a semiconductor fin disposed above a semiconductor substrate. The semiconductor fin has a central protruding or recessed segment spaced apart from a pair of protruding outer segments along a length of the semiconductor fin. A cladding layer region is disposed on the central protruding or recessed segment of the semiconductor fin. A gate stack is disposed on the cladding layer region. Source/drain regions are disposed in the pair of protruding outer segments of the semiconductor fin.

Abstract: Techniques related to III-N transistors having enhanced breakdown voltage, systems incorporating such transistors, and methods for forming them are discussed. Such transistors include a hardmask having an opening over a substrate, a source, a drain, and a channel between the source and drain, and a portion of the source or the drain disposed over the opening of the hardmask.

Abstract: Vertical semiconductor devices having selectively regrown top contacts and method of fabricating vertical semiconductor devices having selectively regrown top contacts are described. For example, a semiconductor device includes a substrate having a surface. A first source/drain region is disposed on the surface of the substrate. A vertical channel region is disposed on the first source/drain region and has a first width parallel with the surface of the substrate. A second source/drain region is disposed on the vertical channel region and has a second width parallel with and substantially greater than the first width. A gate stack is disposed on and completely surrounds a portion of the vertical channel region.

Abstract: A quantum well transistor has a germanium quantum well channel region. A silicon-containing etch stop layer provides easy placement of a gate dielectric close to the channel. A group III-V barrier layer adds strain to the channel. Graded silicon germanium layers above and below the channel region improve performance. Multiple gate dielectric materials allow use of a high-k value gate dielectric.

Abstract: Aspect ratio trapping (ART) approaches for fabricating vertical semiconductor devices and vertical semiconductor devices fabricated there from are described. For example, a semiconductor device includes a substrate with an uppermost surface having a first lattice constant. A first source/drain region is disposed on the uppermost surface of the substrate and has a second, different, lattice constant. A vertical channel region is disposed on the first source/drain region. A second source/drain region is disposed on the vertical channel region. A gate stack is disposed on and completely surrounds a portion of the vertical channel region.

Abstract: III-N transistors with recessed gates. An epitaxial stack includes a doped III-N source/drain layer and a III-N etch stop layer disposed between a the source/drain layer and a III-N channel layer. An etch process, e.g., utilizing photochemical oxidation, selectively etches the source/drain layer over the etch stop layer. A gate electrode is disposed over the etch stop layer to form a recessed-gate III-N HEMT. At least a portion of the etch stop layer may be oxidized with a gate electrode over the oxidized etch stop layer for a recessed gate III-N MOS-HEMT including a III-N oxide. A high-k dielectric may be formed over the oxidized etch stop layer with a gate electrode over the high-k dielectric to form a recessed gate III-N MOS-HEMT having a composite gate dielectric stack.

Abstract: An embodiment includes a device comprising: a first epitaxial layer, coupled to a substrate, having a first lattice constant; a second epitaxial layer, on the first layer, having a second lattice constant; a third epitaxial layer, contacting an upper surface of the second layer, having a third lattice constant unequal to the second lattice constant; and an epitaxial device layer, on the third layer, including a channel region; wherein (a) the first layer is relaxed and includes defects, (b) the second layer is compressive strained and the third layer is tensile strained, and (c) the first, second, third, and device layers are all included in a trench. Other embodiments are described herein.

Abstract: Embodiments of the present disclosure provide contact techniques and configurations for reducing parasitic resistance in nanowire transistors. In one embodiment, an apparatus includes a semiconductor substrate, an isolation layer formed on the semiconductor substrate, a channel layer including nanowire material formed on the isolation layer to provide a channel for a transistor, and a contact coupled with the channel layer, the contact being configured to surround, in at least one planar dimension, nanowire material of the channel layer and to provide a source terminal or drain terminal for the transistor.

Abstract: An embodiment includes a III-V material based device, comprising: a first III-V material based buffer layer on a silicon substrate; a second III-V material based buffer layer on the first III-V material based buffer layer, the second III-V material including aluminum; and a III-V material based device channel layer on the second III-V material based buffer layer. Another embodiment includes the above subject matter and the first and second III-V material based buffer layers each have a lattice parameter equal to the III-V material based device channel layer. Other embodiments are included herein.

Abstract: Transistors for high voltage and high frequency operation. A non-planar, polar crystalline semiconductor body having a top surface disposed between first and second opposite sidewalls includes a channel region with a first crystalline semiconductor layer disposed over the first and second sidewalls. The first crystalline semiconductor layer is to provide a two dimensional electron gas (2DEG) within the channel region. A gate structure is disposed over the first crystalline semiconductor layer along at least the second sidewall to modulate the 2DEG. First and second sidewalls of the non-planar polar crystalline semiconductor body may have differing polarity, with the channel proximate to a first of the sidewalls. The gate structure may be along a second of the sidewalls to gate a back barrier. The polar crystalline semiconductor body may be a group III-nitride formed on a silicon substrate with the (1010) plane on a (110) plane of the silicon.

Abstract: Tunneling field effect transistors (TFETs) for CMOS architectures and approaches to fabricating N-type and P-type TFETs are described. For example, a tunneling field effect transistor (TFET) includes a homojunction active region disposed above a substrate. The homojunction active region includes a relaxed Ge or GeSn body having an undoped channel region therein. The homojunction active region also includes doped source and drain regions disposed in the relaxed Ge or GeSn body, on either side of the channel region. The TFET also includes a gate stack disposed on the channel region, between the source and drain regions. The gate stack includes a gate dielectric portion and gate electrode portion.

Abstract: A group III-N nanowire is disposed on a substrate. A longitudinal length of the nanowire is defined into a channel region of a first group III-N material, a source region electrically coupled with a first end of the channel region, and a drain region electrically coupled with a second end of the channel region. A second group III-N material on the first group III-N material serves as a charge inducing layer, and/or barrier layer on surfaces of nanowire. A gate insulator and/or gate conductor coaxially wraps completely around the nanowire within the channel region. Drain and source contacts may similarly coaxially wrap completely around the drain and source regions.

Abstract: A quantum well transistor has a germanium quantum well channel region. A silicon-containing etch stop layer provides easy placement of a gate dielectric close to the channel. A group III-V barrier layer adds strain to the channel. Graded silicon germanium layers above and below the channel region improve performance. Multiple gate dielectric materials allow use of a high-k value gate dielectric.

Abstract: Techniques are disclosed for forming a GaN transistor on a semiconductor substrate. An insulating layer forms on top of a semiconductor substrate. A trench, filled with a trench material comprising a III-V semiconductor material, forms through the insulating layer and extends into the semiconductor substrate. A channel structure, containing III-V material having a defect density lower than the trench material, forms directly on top of the insulating layer and adjacent to the trench. A source and drain form on opposite sides of the channel structure, and a gate forms on the channel structure. The semiconductor substrate forms a plane upon which both GaN transitors and other transistors can form.

Abstract: A III-N semiconductor channel is compositionally graded between a transition layer and a III-N polarization layer. In embodiments, a gate stack is deposited over sidewalls of a fin including the graded III-N semiconductor channel allowing for formation of a transport channel in the III-N semiconductor channel adjacent to at least both sidewall surfaces in response to a gate bias voltage. In embodiments, a gate stack is deposited completely around a nanowire including a III-N semiconductor channel compositionally graded to enable formation of a transport channel in the III-N semiconductor channel adjacent to both the polarization layer and the transition layer in response to a gate bias voltage.

Abstract: Embodiments of the present disclosure provide contact techniques and configurations for reducing parasitic resistance in nanowire transistors. In one embodiment, an apparatus includes a semiconductor substrate, an isolation layer formed on the semiconductor substrate, a channel layer including nanowire material formed on the isolation layer to provide a channel for a transistor, and a contact coupled with the channel layer, the contact being configured to surround, in at least one planar dimension, nanowire material of the channel layer and to provide a source terminal or drain terminal for the transistor.

Abstract: Transistors for high voltage and high frequency operation. A non-planar, polar crystalline semiconductor body having a top surface disposed between first and second opposite sidewalls includes a channel region with a first crystalline semiconductor layer disposed over the first and second sidewalls. The first crystalline semiconductor layer is to provide a two dimensional electron gas (2DEG) within the channel region. A gate structure is disposed over the first crystalline semiconductor layer along at least the second sidewall to modulate the 2DEG. First and second sidewalls of the non-planar polar crystalline semiconductor body may have differing polarity, with the channel proximate to a first of the sidewalls. The gate structure may be along a second of the sidewalls to gate a back barrier. The polar crystalline semiconductor body may be a group III-nitride formed on a silicon substrate with the (1010) plane on a (110) plane of the silicon.

Abstract: Techniques are disclosed for forming a defect-free semiconductor structure on a dissimilar substrate with a multi-aspect ratio mask. The multi-aspect ratio mask comprises a first, second, and third layer formed on a substrate. The second layer has a second opening wider than a first opening and a third opening in the first and third layers, respectively. All three openings are centered along a common central axis. A semiconductor material is grown from the top surface of the substrate and laterally onto the top surface of the first layer within the second opening. The semiconductor material disposed within and vertically below the third opening is etched by using the third layer as an etch mask so that the remaining material that laterally overflowed onto the top surface of the first layer forms a remaining structure.

Abstract: Embodiments of the disclosure described herein comprise a tunneling field effect transistor (TFET) having a drain region, a source region having a conductivity type opposite of the drain region, a channel region disposed between the source region and the drain region, a gate disposed over the channel region, and a heterogeneous pocket disposed near a junction of the source region and the channel region. The heterogeneous pocket comprises a semiconductor material different than the channel region, and comprises a tunneling barrier less than the bandgap in the channel region and forming a quantum well in the channel region to in crease a current through the TFET transistor when a voltage applied to the gate is above a threshold voltage.

Abstract: Techniques are disclosed for providing a low resistance self-aligned contacts to devices formed in a semiconductor heterostructure. The techniques can be used, for example, for forming contacts to the gate, source and drain regions of a quantum well transistor fabricated in III-V and SiGe/Ge material systems. Unlike conventional contact process flows which result in a relatively large space between the source/drain contacts to gate, the resulting source and drain contacts provided by the techniques described herein are self-aligned, in that each contact is aligned to the gate electrode and isolated therefrom via spacer material.