Abstract:
Methods for self-aligned gate-first VFETs using gate-spacer recess and the resulting devices are disclosed. Embodiments include providing a substrate including adjacent transistor regions; forming adjacent and spaced fin-structures each including hardmask over a fin and over a different transistor region; forming a gate-dielectric and metal-spacer consecutively on each side of each fin-structure; forming a liner on all exposed surfaces of the hardmask, gate-dielectrics, and metal-spacers and the substrate; forming an ILD filling spaces between the fin-structures and coplanar with an upper surface of the liner; removing the liner over the fin-structures; removing the hardmask and recessing the liner, the gate-dielectrics and metal-spacers of each fin-structure creating cavities in the ILD; forming a low-k spacer on sidewalls of and over the metal-spacers and liners in each cavity; forming a top S/D structure over the gate-dielectric and fin in each cavity; and forming a top S/D contact over each top S/D structure.
Abstract:
One illustrative method disclosed herein includes forming first sacrificial gate structures above a fin for two active gates and a dummy gate, removing the first sacrificial gate structure for the dummy gate so as to define a cavity that exposes the fin while leaving the first sacrificial gate structures for the two active gates intact, etching through the cavity to form a trench in the fin under the cavity, forming a second sacrificial gate structure for the dummy gate, removing the first sacrificial gate structures for the two active gates and the second sacrificial gate structure for the dummy gate so as to define a replacement gate cavity for the two active gates and the dummy gate, and forming a replacement gate structure in each of the replacement gate cavities, wherein the replacement gate structure for the dummy gate extends into the trench in the fin.
Abstract:
One illustrative method disclosed herein includes forming first sacrificial gate structures above a fin for two active gates and a dummy gate, removing the first sacrificial gate structure for the dummy gate so as to define a cavity that exposes the fin while leaving the first sacrificial gate structures for the two active gates intact, etching through the cavity to form a trench in the fin under the cavity, forming a second sacrificial gate structure for the dummy gate, removing the first sacrificial gate structures for the two active gates and the second sacrificial gate structure for the dummy gate so as to define a replacement gate cavity for the two active gates and the dummy gate, and forming a replacement gate structure in each of the replacement gate cavities, wherein the replacement gate structure for the dummy gate extends into the trench in the fin.
Abstract:
Methods of fabricating circuit structures including FinFET structures are provided, including: providing a substrate and a first material having a first threshold voltage above the substrate, and a second material having a second threshold voltage lower than the first threshold voltage above the first material; forming fins having base fin portions formed from the first material and upper fin portions formed from the second material; providing gate structures over the fins to form one or more FinFET structures, wherein the gate structures wrap around at least the upper fin portions and have an operating voltage lower than the first threshold voltage and higher than the second threshold voltage, so that the upper fin portions define a channel size of the one or more FinFET structures. Circuit structures including FinFET structures are also provided, in which the FinFET structures have a uniform channel size defined only by upper fin portions thereof.