Abstract:
One illustrative method disclosed herein includes, among other things, defining a cavity in a plurality of layers of material positioned above a bottom source/drain (S/D) layer of semiconductor material, wherein a portion of the bottom source/drain (S/D) layer of semiconductor material is exposed at the bottom of the cavity, and performing at least one epi deposition process to form a vertically oriented channel semiconductor structure on the bottom source/drain (S/D) layer of semiconductor material and in the cavity and a top source/drain (S/D) layer of semiconductor material above the vertically oriented channel semiconductor structure. In this example, the method further includes removing at least one of the plurality of layers of material to thereby expose an outer perimeter surface of the vertically oriented channel semiconductor structure and forming a gate structure around the vertically oriented channel semiconductor structure.
Abstract:
A semiconductor stack of a FinFET in fabrication includes a bulk silicon substrate, a selectively oxidizable sacrificial layer over the bulk substrate and an active silicon layer over the sacrificial layer. Fins are etched out of the stack of active layer, sacrificial layer and bulk silicon. A conformal oxide deposition is made to encapsulate the fins, for example, using a HARP deposition. Relying on the sacrificial layer having a comparatively much higher oxidation rate than the active layer or substrate, selective oxidization of the sacrificial layer is performed, for example, by annealing. The presence of the conformal oxide provides structural stability to the fins, and prevents fin tilting, during oxidation. Selective oxidation of the sacrificial layer provides electrical isolation of the top active silicon layer from the bulk silicon portion of the fin, resulting in an SOI-like structure. Further fabrication may then proceed to convert the active layer to the source, drain and channel of the FinFET. The oxidized sacrificial layer under the active channel prevents punch-through leakage in the final FinFET structure.
Abstract:
One method disclosed herein includes, among other things, forming a patterned fin having a thickness that is equal to or greater than a target final fin height for a replacement fin, performing an etching process through the patterned fin etch mask to form a plurality of trenches in a semiconductor substrate to define a substrate fin and forming a recessed layer of insulating material in the trenches so as to expose the patterned fin etch. The method also includes forming a layer of CTE-matching material around the exposed patterned fin etch mask, removing the patterned fin etch mask to thereby define a replacement fin cavity and expose a surface of the substrate fin, forming the replacement fin on the substrate fin and in the replacement fin cavity, removing the layer of CTE-matching material and forming a gate structure around at least a portion of the replacement fin.
Abstract:
One method of forming epi semiconductor cladding materials in the channel region of a semiconductor device is disclosed which includes forming a sacrificial gate structure around a portion of an initial fin, forming a sidewall spacer adjacent opposite sides of the sacrificial gate structure and removing the sacrificial gate structure so as to thereby define a replacement gate cavity, performing an etching process through the replacement gate cavity to remove portions of the initial fin so as to thereby define a reduced size fin and recesses under the sidewall spacers, forming at least one replacement epi semiconductor cladding material around the reduced size fin in the replacement gate cavity and in the recesses under the sidewall spacers, and forming a replacement gate structure within the replacement gate cavity around the at least one replacement epi semiconductor cladding material.
Abstract:
A method includes forming a fin on a semiconductor substrate and forming recesses on sidewalls of the fin. A silicon alloy material is formed in the recesses. A thermal process is performed to define a silicon alloy fin portion from the silicon alloy material and the fin. A semiconductor device includes a substrate, a fin defined on the substrate and an isolation structure disposed adjacent the fin. A first portion of the fin extending above the isolation structure has a substantially vertical sidewall and a different material composition than a second portion of the fin not extending above the isolation structure.
Abstract:
One illustrative device disclosed herein includes a fin defined in a semiconductor substrate having a crystalline structure, wherein at least a sidewall of the fin is positioned substantially in a crystallographic direction of the substrate, a gate structure positioned around the fin, an outermost sidewall spacer positioned adjacent opposite sides of the gate structure, and an epi semiconductor material formed around portions of the fin positioned laterally outside of the outermost sidewall spacers in the source/drain regions of the device, wherein the epi semiconductor material has a substantially uniform thickness along the sidewalls of the fin.
Abstract:
Commonly fabricated FinFET type semiconductor devices with different (i.e., both taller and shorter) heights of an entirety of or only the channel region of some of the fins. Where only the channel of some of the fins has a different height, the sources and drains have a common height higher than those channels. The different fin heights are created by recessing some of the fins, and where only the channels have different heights, the difference is created by exposing a top surface of each channel intended to be shorter, the other channels being masked, and partially recessing the exposed channel(s). In both cases, the mask(s) may then be removed and conventional FinFET processing may proceed.
Abstract:
An aspect of the disclosure includes a semiconductor structure comprising: a set of fins on a substrate, the set of fins including a relaxed silicon germanium layer; and a dielectric between each fin in the set of fins; wherein each fin in a n-type field effect transistor (nFET) region further includes a strained silicon layer over the relaxed silicon germanium layer of each fin in the nFET region; wherein each fin in a p-type field effect transistor (pFET) region further includes a strained silicon germanium layer over the relaxed silicon germanium layer of each fin in the pFET region.
Abstract:
One illustrative method disclosed herein includes, among other things, removing at least a portion of a vertical height of portions of an overall fin structure that are not covered by a gate structure so as to result in the definition of a fin cavity in a layer of insulating material and the definition of a remaining portion of the overall fin structure that is positioned under the gate structure, wherein the remaining portion comprises a channel portion and a lower portion located under the channel portion. The method continues with the formation of a first semiconductor material within at least the fin cavity and the formation of a second semiconductor material on the first semiconductor material and on exposed edges of the channel portion.
Abstract:
One illustrative method disclosed herein includes, among other things, forming a composite fin structure that is comprised of a first germanium-containing semiconductor material having a first concentration of germanium and a tensile-strained second semiconductor material (having a lesser germanium concentration) positioned on the first germanium-containing semiconductor material and performing a thermal anneal process to convert the first germanium-containing semiconductor material portion of the composite fin structure into a germanium-containing oxide isolation region positioned under the second semiconductor material that is a tensile-strained final fin for an NMOS FinFET device.