Abstract:
Integrated circuit structures including increased transistor source/drain (S/D) contact area using a sacrificial S/D layer are provided herein. The sacrificial layer, which includes different material from the S/D material, is deposited into the S/D trenches prior to the epitaxial growth of that S/D material, such that the sacrificial layer acts as a space-holder below the S/D material. During S/D contact processing, the sacrificial layer can be selectively etched relative to the S/D material to at least partially remove it, leaving space below the S/D material for the contact metal to fill. In some cases, the contact metal is also between portions of the S/D material. In some cases, the contact metal wraps around the epi S/D, such as when dielectric wall structures on either side of the S/D region are employed. By increasing the S/D contact area, the contact resistance is reduced, thereby improving the performance of the transistor device.
Abstract:
Isolation schemes for gate-all-around (GAA) transistor devices are provided herein. In some cases, the isolation schemes include changing the semiconductor nanowires/nanoribbons in a targeted channel region between active or functional transistor devices to electrically isolate those active devices. The targeted channel region is referred to herein as a dummy channel region, as it is not used as an actual channel region for an active or functional transistor device. The semiconductor nanowires/nanoribbons in the dummy channel region can be changed by converting them to an electrical insulator and/or by adding dopant that is opposite in type relative to surrounding source/drain material (to create a p-n junction). The isolation schemes described herein enable neighboring active devices to retain strain in the nanowires/nanoribbons of their channel regions, thereby improving device performance.
Abstract:
Techniques are disclosed for forming dual-strain fins for co-integrated n-MOS and p-MOS devices. The techniques can be used to monolithically form tensile-strained fins to be used for n-MOS devices and compressive-strained fins to be used for p-MOS devices utilizing the same substrate, such that a single integrated circuit (IC) can include both of the devices. In some instances, the oppositely stressed fins may be achieved by employing a relaxed SiGe (rSiGe) layer from which the tensile and compressive-strained material can be formed. In some instances, the techniques include the formation of tensile-stressed Si and/or SiGe fins and compressive-stressed SiGe and/or Ge fins using a single relaxed SiGe layer to enable the co-integration of n-MOS and p-MOS devices, where each set of devices includes preferred materials and preferred stress/strain to enhance their respective performance. In some cases, improvements of at least 25% in drive current can be obtained.
Abstract:
Integrated circuit structures including a buried etch-stop layer to help control transistor source/drain depth are provided herein. The buried etch-stop layer addresses the issue of the source/drain etch (or epi-undercut (EUC) etch) going below the bottom of the active height of the channel region, as such an issue can result in un-controlled sub-fin leakage that causes power consumption degradation and other undesired performance issues. The buried etch-stop layer is formed below the channel material, such as in the epitaxial stack that includes the channel material, and acts to slow the removal of material after the channel material has been removed when etching to form the source/drain trenches. In other words, the buried etch-stop layer includes different material from the channel material that can be etched, for at least one given etchant, at a relatively slower rate than the channel material to help control the source/drain trench depth.
Abstract:
Embodiments of the present disclosure describe techniques for backside isolation for devices of an integrated circuit (IC) and associated configurations. The IC may include a plurality of devices (e.g., transistors) formed on a semiconductor substrate. The semiconductor substrate may include substrate regions on which one or more devices are formed. Trenches may be disposed between the devices on the semiconductor substrate. Portions of the semiconductor substrate between the substrate regions may be removed to expose the corresponding trenches and form isolation regions. An insulating material may be formed in the isolation regions. Other embodiments may be described and/or claimed.
Abstract:
Techniques are disclosed for incorporating high mobility strained channels into fin-based NMOS transistors (e.g., FinFETs such as double-gate, trigate, etc), wherein a stress material is cladded onto the channel area of the fin. In one example embodiment, a germanium or silicon germanium film is cladded onto silicon fins in order to provide a desired tensile strain in the core of the fin, although other fin and cladding materials can be used. The techniques are compatible with typical process flows, and cladding deposition can occur at a plurality of locations within typical process flow. In various embodiments, fins may be formed with a minimum width (or later thinned) so as to improve transistor performance. In some embodiments, a thinned fin also increases tensile strain across the core of a cladded fin. In some cases, strain in the core may be further enhanced by adding an embedded silicon epitaxial source and drain.
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 are disclosed for converting a strain-inducing semiconductor buffer layer into an electrical insulator at one or more locations of the buffer layer, thereby allowing an above device layer to have a number of benefits, which in some embodiments include those that arise from being grown on a strain-inducing buffer and having a buried electrical insulator layer. For instance, having a buried electrical insulator layer (initially used as a strain-inducing buffer during fabrication of the above active device layer) between the Fin and substrate of a non-planar integrated transistor circuit may simultaneously enable a low-doped Fin with high mobility, desirable device electrostatics and elimination or otherwise reduction of substrate junction leakage. Also, the presence of such an electrical insulator under the source and drain regions may further significantly reduce junction leakage. In some embodiments, substantially the entire buffer layer is converted to an electrical insulator.
Abstract:
Techniques are disclosed for converting a strain-inducing semiconductor buffer layer into an electrical insulator at one or more locations of the buffer layer, thereby allowing an above device layer to have a number of benefits, which in some embodiments include those that arise from being grown on a strain-inducing buffer and having a buried electrical insulator layer. For instance, having a buried electrical insulator layer (initially used as a strain-inducing buffer during fabrication of the above active device layer) between the Fin and substrate of a non-planar integrated transistor circuit may simultaneously enable a low-doped Fin with high mobility, desirable device electrostatics and elimination or otherwise reduction of substrate junction leakage. Also, the presence of such an electrical insulator under the source and drain regions may further significantly reduce junction leakage. In some embodiments, substantially the entire buffer layer is converted to an electrical insulator.
Abstract:
Techniques are disclosed for incorporating high mobility strained channels into fin-based NMOS transistors (e.g., FinFETs such as double-gate, trigate, etc), wherein a stress material is cladded onto the channel area of the fin. In one example embodiment, a germanium or silicon germanium film is cladded onto silicon fins in order to provide a desired tensile strain in the core of the fin, although other fin and cladding materials can be used. The techniques are compatible with typical process flows, and cladding deposition can occur at a plurality of locations within typical process flow. In various embodiments, fins may be formed with a minimum width (or later thinned) so as to improve transistor performance. In some embodiments, a thinned fin also increases tensile strain across the core of a cladded fin. In some cases, strain in the core may be further enhanced by adding an embedded silicon epitaxial source and drain.