Abstract:
Deep gate-all-around semiconductor devices having germanium or group III-V active layers are described. For example, a non-planar semiconductor device includes a hetero-structure disposed above a substrate. The hetero-structure includes a hetero-junction between an upper layer and a lower layer of differing composition. An active layer is disposed above the hetero-structure and has a composition different from the upper and lower layers of the hetero-structure. A gate electrode stack is disposed on and completely surrounds a channel region of the active layer, and is disposed in a trench in the upper layer and at least partially in the lower layer of the hetero-structure. Source and drain regions are disposed in the active layer and in the upper layer, but not in the lower layer, on either side of the gate electrode stack.
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.
Abstract:
Techniques are disclosed for enabling multi-sided condensation of semiconductor fins. The techniques can be employed, for instance, in fabricating fin-based transistors. In one example case, a strain layer is provided on a bulk substrate. The strain layer is associated with a critical thickness that is dependent on a component of the strain layer, and the strain layer has a thickness lower than or equal to the critical thickness. A fin is formed in the substrate and strain layer, such that the fin includes a substrate portion and a strain layer portion. The fin is oxidized to condense the strain layer portion of the fin, so that a concentration of the component in the strain layer changes from a pre-condensation concentration to a higher post-condensation concentration, thereby causing the critical thickness to be exceeded.
Abstract:
Deep gate-all-around semiconductor devices having germanium or group III-V active layers are described. For example, a non-planar semiconductor device includes a hetero-structure disposed above a substrate. The hetero-structure includes a hetero-junction between an upper layer and a lower layer of differing composition. An active layer is disposed above the hetero-structure and has a composition different from the upper and lower layers of the hetero-structure. A gate electrode stack is disposed on and completely surrounds a channel region of the active layer, and is disposed in a trench in the upper layer and at least partially in the lower layer of the hetero-structure. Source and drain regions are disposed in the active layer and in the upper layer, but not in the lower layer, on either side of the gate electrode stack.
Abstract:
A surface channel transistor is provided in a semiconductive device. The surface channel transistor is either a PMOS or an NMOS device. Epitaxial layers are disposed above the surface channel transistor to cause an increased bandgap phenomenon nearer the surface of the device. A process of forming the surface channel transistor includes grading the epitaxial layers.
Abstract:
Conductivity improvements in III-V semiconductor devices are described. A first improvement includes a barrier layer that is not coextensively planar with a channel layer. A second improvement includes an anneal of a metal/Si, Ge or SiliconGermanium/III-V stack to form a metal-Silicon, metal-Germanium or metal-SiliconGermanium layer over a Si and/or Germanium doped III-V layer. Then, removing the metal layer and forming a source/drain electrode on the metal-Silicon, metal-Germanium or metal-SiliconGermanium layer. A third improvement includes forming a layer of a Group IV and/or Group VI element over a III-V channel layer, and, annealing to dope the III-V channel layer with Group IV and/or Group VI species. A fourth improvement includes a passivation and/or dipole layer formed over an access region of a III-V device.
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.
Abstract:
Trench-confined selective epitaxial growth process in which epitaxial growth of a semiconductor device layer proceeds within the confines of a trench. In embodiments, a trench is fabricated to include a pristine, planar semiconductor seeding surface disposed at the bottom of the trench. Semiconductor regions around the seeding surface may be recessed relative to the seeding surface with Isolation dielectric disposed there on to surround the semiconductor seeding layer and form the trench. In embodiments to form the trench, a sacrificial hardmask fin may be covered in dielectric which is then planarized to expose the hardmask fin, which is then removed to expose the seeding surface. A semiconductor device layer is formed from the seeding surface through selective heteroepitaxy. In embodiments, non-planar devices are formed from the semiconductor device layer by recessing a top surface of the isolation dielectric. In embodiments, non-planar devices CMOS devices having high carrier mobility may be made from the semiconductor device layer.
Abstract:
A method to form a strain-inducing semiconductor region is described. In one embodiment, formation of a strain-inducing semiconductor region laterally adjacent to a crystalline substrate results in a uniaxial strain imparted to the crystalline substrate, providing a strained crystalline substrate. In another embodiment, a semiconductor region with a crystalline lattice of one or more species of charge-neutral lattice-forming atoms imparts a strain to a crystalline substrate, wherein the lattice constant of the semiconductor region is different from that of the crystalline substrate, and wherein all species of charge-neutral lattice-forming atoms of the semiconductor region are contained in the crystalline substrate.
Abstract:
Trench-confined selective epitaxial growth process in which epitaxial growth of a semiconductor device layer proceeds within the confines of a trench. In embodiments, a trench is fabricated to include a pristine, planar semiconductor seeding surface disposed at the bottom of the trench. Semiconductor regions around the seeding surface may be recessed relative to the seeding surface with Isolation dielectric disposed there on to surround the semiconductor seeding layer and form the trench. In embodiments to form the trench, a sacrificial hardmask fin may be covered in dielectric which is then planarized to expose the hardmask fin, which is then removed to expose the seeding surface. A semiconductor device layer is formed from the seeding surface through selective heteroepitaxy. In embodiments, non-planar devices are formed from the semiconductor device layer by recessing a top surface of the isolation dielectric. In embodiments, non-planar devices CMOS devices having high carrier mobility may be made from the semiconductor device layer.