Abstract: Techniques are provided herein to form gate-all-around (GAA) semiconductor devices utilizing a metal fill in an epi region of a stacked transistor configuration. In one example, an n-channel device and the p-channel device may both be GAA transistors each having any number of nanoribbons extending in the same direction where the n-channel device is located vertically above the p-channel device (or vice versa). Source or drain regions are adjacent to both ends of the n-channel device and the p-channel device. A metal fill may be provided around the source or drain region of the bottom semiconductor device to provide a high contact area between the highly conductive metal fill and the epitaxial material of that source or drain region. Metal fill may also be used around the top source or drain region to further improve conductivity throughout both of the stacked source or drain regions.

Abstract: In one embodiment, an integrated circuit includes a silicon substrate, a gallium nitride (GaN) layer above the silicon substrate, a bonding layer above the GaN layer, and a silicon layer above the bonding layer. Further, the integrated circuit includes a first transistor on the GaN layer and a second transistor on the silicon layer.

Abstract: Techniques to form wrap-around contacts in a stacked transistor architecture. An example includes a first source or drain region and a second source or drain region spaced from and over the first source or drain region. A conductive contact is on a top surface of the second source or drain and extends down one or more side surfaces of the second source or drain region such that the conductive contact is laterally adjacent to a bottom surface of the second source or drain region. In some cases, the conductive contact is also on a top surface of the first source or drain region, and/or extends down a side surface of the first source or drain region. In some cases, a second conductive contact is on a bottom surface of the first source or drain region, and may extend up a side surface the first source or drain region.

Abstract: A probabilistic bit (p-bit) comprises a magnetic tunnel junction (MTJ) comprising a free layer whose magnetization orientation randomly fluctuates in the presence of thermal noise. The p-bit MTJ comprises a reference layer, a free layer, and an insulating layer between the reference and free layers. The reference layer and the free layer comprise synthetic antiferromagnets. The use of a synthetic antiferromagnet for the reference layer reduces the amount of stray magnetic field that can impact the magnetization of the free layer and the use of a synthetic antiferromagnet for the free layer reduces stray magnetic field bias on p-bit random number generation. Tuning the thickness of the nonmagnetic layer of synthetic antiferromagnet free layer can result in faster random number generation time relative to a comparable MTJ with a free layer comprising a single-layer ferromagnet.

Abstract: Techniques are provided herein to form semiconductor devices having an epi region contact with a high contact area to either or both top and bottom epi regions in a stacked transistor configuration. In one example, two different semiconductor devices include an n-channel device located vertically above a p-channel device (or vice versa). Source or drain regions are adjacent to both ends of the n-channel device and the p-channel device, such that a source or drain region of one device is located vertically over the source or drain region of the other device. A contact structure may be formed that has a greater width when contacting a top surface of the bottom source or drain region than when contacting a side surface of the top source or drain region. The higher contact area on the bottom source or drain region provides a lower contact resistance compared to previous architectures.

Abstract: Techniques are provided herein to form semiconductor devices having a stacked transistor configuration. An n-channel device and a p-channel device may both be gate-all-around (GAA) transistors each having any number of nanoribbons extending in the same direction where one device is located vertically above the other device. According to some embodiments, the n-channel device and the p-channel device conductively share the same gate, and a width of the gate structure around one device is greater than the width of the gate structure around the other device. According to some other embodiments, the n-channel device and the p-channel device each have a separate gate structure that is isolated from the other using a dielectric layer between them. A gate contact is adjacent to the upper device and contacts the gate structure of the other lower device.

Abstract: An integrated circuit die has a layer of first semiconductor material comprising a Group III element and nitrogen and having a first bandgap. A first transistor structure on a first region of the die has: a quantum well (QW) structure that includes at least a portion of the first semiconductor material and a second semiconductor material having a second bandgap smaller than the first bandgap, a first source and a first drain in contact with the QW structure, and a gate structure in contact with the QW structure between the first source and the first drain. A second transistor structure on a second region of the die has a second source and a second drain in contact with a semiconductor body, and a second gate structure in contact with the semiconductor body between the second source and the second drain. The semiconductor body comprises a Group III element and nitrogen.

Abstract: Techniques are disclosed for forming high frequency film bulk acoustic resonator (FBAR) devices having multiple resonator thicknesses on a common substrate. A piezoelectric stack is formed in an STI trench and overgrown onto the STI material. In some cases, the piezoelectric stack can include epitaxially grown AlN. In some cases, the piezoelectric stack can include single crystal (epitaxial) AlN in combination with polycrystalline (e.g., sputtered) AlN. The piezoelectric stack thus forms a central portion having a first resonator thickness and end wings extending from the central portion having a different resonator thickness. Each wing may also have different thicknesses. Thus, multiple resonator thicknesses can be achieved on a common substrate, and hence, multiple resonant frequencies on that same substrate. The end wings can have metal electrodes formed thereon, and the central portion can have a plurality of IDT electrodes patterned thereon.

Abstract: Disclosed herein are IC structures, packages, and device assemblies with III-N transistors that include additional materials, referred to herein as “stressor materials,” which may be selectively provided over portions of polarization materials to locally increase or decrease the strain in the polarization material. Providing a compressive stressor material may decrease the tensile stress imposed by the polarization material on the underlying portion of the III-N semiconductor material, thereby decreasing the two-dimensional electron gas (2DEG) and increasing a threshold voltage of a transistor. On the other hand, providing a tensile stressor material may increase the tensile stress imposed by the polarization material, thereby increasing the 2DEG and decreasing the threshold voltage. Providing suitable stressor materials enables easier and more accurate control of threshold voltage compared to only relying on polarization material recess.

Abstract: A method for forming III-N structures of desired nanoscale dimensions is disclosed. The method is based on, first, providing a material to serve as a shell inside which a cavity can be formed, followed by using epitaxial growth to fill the cavity with III-N semiconductor(s). Filling a cavity of specified shape and dimensions with a III-N semiconductor results in formation of a III-N structure which has shape and dimensions defined by those of the cavity in the shell, advantageously enabling formation of III-N structures on a nanometer scale without having to rely on etching of III-N materials. Ensuring that at least a part of the III-N material in the cavity is formed by lateral epitaxial overgrowth allows obtaining high quality III-N semiconductor in that part without having to grow a thick layer. Disclosed III-N nanostructures can serve as foundation for fabricating III-N device components, e.g. III-N transistors, having non-planar architecture.

Abstract: Integrated circuits with III-N metal-insulator-semiconductor field effect transistor (MISFET) structures that employ one or more gate dielectric materials that differ across the MISFETs. Gate dielectric materials may be selected to modulate dielectric breakdown strength and/or threshold voltage between transistors. Threshold voltage may be modulated between two MISFET structures that may be substantially the same but for the gate dielectric. Control of the gate dielectric material may render some MISFETs to be operable in depletion mode while other MISFETs are operable in enhancement mode. Gate dielectric materials may be varied by incorporating multiple dielectric materials in some MISFETs of an IC while other MISFETs of the IC may include only a single dielectric material. Combinations of gate dielectric material layers may be selected to provide a menu of low voltage, high voltage, enhancement and depletion mode MISFETs within an IC.

Abstract: Disclosed herein are IC structures, packages, and devices assemblies that use ions or fixed charge to create field plate structures which are embedded in a dielectric material between gate and drain electrodes of a transistor. Ion- or fixed charge-based field plate structures may provide viable approaches to changing the distribution of electric field at a transistor drain to increase the breakdown voltage of a transistor without incurring the large parasitic capacitances associated with the use of metal field plates. In one aspect, an IC structure includes a transistor, a dielectric material between gate and drain electrodes of the transistor, and an ion- or fixed charge-based region within the dielectric material, between the gate and the drain electrodes. Such an ion- or fixed charge-based region realizes an ion- or fixed charge-based field plate structure. Optionally, the IC structure may include multiple ion- or fixed charge-based field plate structures.

Abstract: Disclosed herein are IC structures, packages, and devices that include thin-film transistors (TFTs) integrated on the same substrate/die/chip as III-N devices, e.g., III-N transistors. In various aspects, TFTs integrated with III-N transistors have a channel and source/drain materials that include one or more of a crystalline material, a polycrystalline semiconductor material, or a laminate of crystalline and polycrystalline materials. In various aspects, TFTs integrated with III-N transistors are engineered to include one or more of 1) graded dopant concentrations in their source/drain regions, 2) graded dopant concentrations in their channel regions, and 3) thicker and/or composite gate dielectrics in their gate stacks.

Abstract: Techniques are provided herein to form semiconductor devices having backside contacts. Sacrificial plugs are formed first within a substrate at particular locations to align with source and drain regions during a later stage of processing. Another wafer is subsequently bonded to the surface of the substrate and is thinned to effectively transfer different material layers to the top surface of the substrate. One of the transferred layers acts as a seed layer for the growth of additional semiconductor material used to form semiconductor devices. The source and drain regions of the semiconductor devices are sufficiently aligned over the previously formed sacrificial plugs. A backside portion of the substrate may be removed to expose the sacrificial plugs from the backside. Removal of the plugs and replacement of the recesses left behind with conductive material forms the conductive backside contacts to the source or drain regions.

Abstract: Techniques are provided herein to form gate-all-around (GAA) semiconductor devices, such as those having a stacked transistor configuration. In one example case, two different semiconductor devices may both be GAA transistors each having any number of nanoribbons extending in the same (e.g., horizontal) direction where one device is located vertically above the other device. An internal spacer structure extends between the nanoribbons of both devices along the vertical direction, where the spacer structure includes one or more rib features between the two devices. A gate structure that includes one or more gate dielectric layers and one or more gate electrode layers may be formed around the nanoribbons of both devices, in some cases. In other cases, a split-gate configuration is used where upper and lower gate structures are separated by an isolation structure. Forksheet transistors and other GAA configurations may be formed using the techniques as well.

Abstract: Techniques are provided herein to form semiconductor devices having a stacked transistor configuration. In an example, an upper (e.g., n-channel) device and a lower (e.g., p-channel) device may both be gate-all-around (GAA) transistors each having any number of nanoribbons extending in the same direction where the upper device is located vertically above the lower device. According to some embodiments, an internal spacer structure extends between the nanoribbons of the upper device and the nanoribbons of the lower device along the vertical direction, where the spacer structure has a stepwise or an otherwise outwardly protruding profile as it extends between the nanoribbons of the upper device and the lower device. Accordingly, in one example, a gate structure formed around the nanoribbons of both the n-channel device and the p-channel device exhibits a greater width in the region between the nanoribbons of the n-channel device and the nanoribbons of the p-channel device.

Abstract: Techniques are provided herein to form a forksheet transistor device with a dielectric overhang structure. The dielectric overhang structure includes a dielectric layer that at least partially hangs over the nanoribbons of each semiconductor device in the forksheet transistor and is directly coupled to, or is an integral part of, the dielectric spine between the semiconductor devices. The overhang structure allows for a higher alignment tolerance when forming different work function metals over each of the different semiconductor devices, which in turn allows for narrower dielectric spines to be used. A first gate structure that includes a first work function metal may be formed around the nanoribbons of the n-channel device and a second gate structure that includes a second work function metal may be formed around the nanoribbons of the p-channel device in the forksheet arrangement.

Abstract: Embodiments of the invention include non-planar InGaZnO (IGZO) transistors and methods of forming such devices. In an embodiment, the IGZO transistor may include a substrate and source and drain regions formed over the substrate. According to an embodiment, an IGZO layer may be formed above the substrate and may be electrically coupled to the source region and the drain region. Further embodiments include a gate electrode that is separated from the IGZO layer by a gate dielectric. In an embodiment, the gate dielectric contacts more than one surface of the IGZO layer. In one embodiment, the IGZO transistor is a finfet transistor. In another embodiment the IGZO transistor is a nanowire or a nanoribbon transistor. Embodiments of the invention may also include a non-planar IGZO transistor that is formed in the back end of line stack (BEOL) of an integrated circuit chip.

Abstract: Embodiments include a transistor and methods of forming a transistor. In an embodiment, the transistor comprises a semiconductor channel, a source electrode on a first side of the semiconductor channel, a drain electrode on a second side of the semiconductor channel, a polarization layer over the semiconductor channel, an insulator stack over the polarization layer, and a gate electrode over the semiconductor channel. In an embodiment, the gate electrode comprises a main body that passes through the insulator stack and the polarization layer, and a first field plate extending out laterally from the main body.

Abstract: In one embodiment, an apparatus includes a source region, a drain region, a channel between the source and drain regions, and a polarization layer on the channel. The channel includes gallium and nitrogen, and the polarization layer includes a group III-nitride (III-N) material. The apparatus further includes a gate structure having a first region and a second region. The first region extends into the polarization layer and includes a metal. The second region is coupled to the first region and includes a polycrystalline semiconductor material.