Abstract:
Epitaxially grow first lower source-drain regions within a substrate. Portions of the substrate adjacent the lower regions are doped to form second lower source-drain regions. An undoped silicon layer is formed over the first and second lower regions. Etch completely through the undoped layer into the first and second lower regions to form fins and to define bottom junctions beneath the fins. The fins and bottom junctions define intermediate cavities. Form lower spacers, gates, and upper spacers in the cavities; form top junctions on outer surfaces of the fins; and form epitaxially grown first upper source-drain regions outward of the upper spacers and opposite the first lower regions. The first upper regions are doped the same as the first lower regions. Form second upper source-drain regions outward of the upper spacers and opposite the second lower regions; these are doped the same as the second lower regions.
Abstract:
A method of forming a semiconductor structure includes forming a first nanosheet stack and a second nanosheet stack on a semiconductor substrate. The first nanosheet stack includes a plurality of alternating first sacrificial layers and first channel layers. The first sacrificial layers each define a first sacrificial height. The second nanosheet stack includes a plurality of alternating second sacrificial layers and second channel layers. The second sacrificial layers each define a second sacrificial height greater than the first sacrificial height of the first sacrificial layers. The method further includes removing the first and second sacrificial layers respectively from the first and second nanosheet stacks. A metal gate is deposited over the first and second nanosheet stacks to form respective first and second nanosheet transistor structures.
Abstract:
A semiconductor device includes a first transistor formed on a substrate, the first transistor including a channel region positioned on the substrate; a second transistor formed on the substrate, the second transistor including a channel region positioned on the substrate; a high-k dielectric layer disposed on the channel region of the first transistor and the channel region of the second transistor; a first transistor metal gate positioned in contact with the high-k dielectric on the first transistor; a second transistor metal gate positioned in contact with the high-k dielectric on the second transistor; an oxygen absorbing barrier disposed in contact with the high-k dielectric between the first transistor and the second transistor; and a conductive electrode material disposed on the first transistor, the second transistor, and the oxygen absorbing barrier.
Abstract:
A semiconductor device includes a first transistor formed on a substrate, the first transistor including a channel region positioned on the substrate; a second transistor formed on the substrate, the second transistor including a channel region positioned on the substrate; a high-k dielectric layer disposed on the channel region of the first transistor and the channel region of the second transistor; a first transistor metal gate positioned in contact with the high-k dielectric on the first transistor; a second transistor metal gate positioned in contact with the high-k dielectric on the second transistor; an oxygen absorbing barrier disposed in contact with the high-k dielectric between the first transistor and the second transistor; and a conductive electrode material disposed on the first transistor, the second transistor, and the oxygen absorbing barrier.
Abstract:
Standard High-K metal gate (HKMG) CMOS technologies fabricated using the replacement metal gate (RMG), also known as gate-last, integration flow, are susceptible to oxygen ingress into the high-K gate dielectric layer and oxygen diffusion into the gate dielectric and semiconductor channel region. The oxygen at the gate dielectric and semiconductor channel interface induces unwanted oxide regrowth that results in an effective oxide thickness increase, and transistor threshold voltage shifts, both of which are highly variable and degrade semiconductor chip performance. By introducing silicon nitride deposited at low temperature, after the metal gate formation, the oxygen ingress and gate dielectric regrowth can be avoided, and a high semiconductor chip performance is maintained.