Vertical gate-all-around device
A vertically protruding structure is formed. The vertically protruding structure includes a substrate, a first semiconductor layer disposed over the substrate, a channel layer disposed over the first semiconductor layer, and a second semiconductor layer disposed over the channel layer. The first semiconductor layer and the second semiconductor layer each contain a first type of semiconductive material. The channel layer contains a second type of semiconductive material different from the first type. First recesses are formed in the first semiconductor layer and the second semiconductor layer. Each of the first recesses protrudes laterally inward. The first recesses are filled with dielectric spacers. The channel layer and the substrate are laterally trimmed. The remaining portions of the channel layer and the dielectric spacers define second recesses that protrude laterally inward. Gate structures are formed in the second recesses.
1 . A device, comprising:
a channel component;
a gate dielectric component located beside the channel component in a first cross-sectional side view, wherein the first cross-sectional side view is defined by a vertical direction and a first horizontal direction;
a gate electrode component, wherein in the first cross-sectional side view, the gate dielectric component surrounds a top surface of the gate electrode component, a bottom surface of the gate electrode component, a first side surface of the gate electrode component, and a second side surface of the gate electrode component opposite the first side surface;
a first spacer component disposed above the gate dielectric component in the vertical direction in the first cross-sectional side view; and
a second spacer component disposed below the gate dielectric component in the vertical direction in the first cross-sectional side view;
wherein a side surface of the gate dielectric component protrudes beyond a side surface of the first spacer component or a side surface of the second spacer component in the first horizontal direction in the first cross-sectional side view.
2 . The device of claim 1 , wherein:
the gate dielectric component surrounds the gate electrode component in 360 degrees in the first cross-sectional side view; and
in a second cross-sectional side view defined by the vertical direction and a second horizontal direction perpendicular to the first horizontal direction, the gate electrode component is surrounded by the gate dielectric component in less than 360 degrees.
3 . The device of claim 2 , further comprising a gate contact, wherein in the second cross-sectional side view:
the gate dielectric component is in direct contact with the top surface, the bottom surface, and the first side surface of the gate electrode component, but not in direct contact with the second side surface of the gate electrode component; and
the gate contact is in direct contact with the second side surface of the gate electrode component.
4 . The device of claim 1 , further comprising an interfacial layer that is disposed between the channel component and the gate dielectric component in the first horizontal direction, wherein the interfacial layer includes a metal germanium oxide, a metal silicon oxide, or a metal germanium silicon oxide.
5 . The device of claim 1 , further comprising:
a first source/drain component disposed above the channel component in the vertical direction in the first cross-sectional side view; and
a second source/drain component disposed below the channel component in the vertical direction in the first cross-sectional side view.
6 . The device of claim 5 , further comprising:
a third spacer component disposed above the first spacer component in the vertical direction in the first cross-sectional side view;
a dummy material disposed below the second spacer component in the vertical direction in the first cross-sectional side view; and
a dielectric component that is in direct contact with side surfaces of the first spacer component, the second spacer component, the third spacer component, the dummy material, and the gate dielectric component.
7 . The device of claim 6 , wherein:
the first source/drain component includes a first portion and a second portion;
the second portion is doped more heavily than the first portion;
the first portion is in direct contact with a side surface of the first spacer component; and
the second portion is in direct contact with a side surface of the third spacer component.
8 . The device of claim 1 , wherein:
the device comprises a vertical gate-all-around (GAA) transistor;
the channel component comprises a nano-structure channel of the vertical GAA transistor; and
the channel component has a greater dimension in the vertical direction than the gate electrode component and the gate dielectric component combined.
9 . A device, comprising:
a channel component;
a first source/drain component disposed above the channel component in a first cross-sectional side view that is defined by a vertical direction and a first horizontal direction;
a second source/drain component disposed below the channel component in the first cross-sectional side view;
a gate structure disposed beside the channel component in the first cross-sectional side view, wherein the gate structure includes a gate dielectric component and a metal-containing gate electrode component, and wherein the metal-containing gate electrode component is surrounded by the gate dielectric component in 360 degrees in the first cross-sectional side view;
a first spacer disposed above the gate structure in the first cross-sectional side view; and
a second spacer disposed below the gate structure in the first cross-sectional side view;
wherein the gate structure laterally protrudes beyond the first spacer or the second spacer in the first horizontal direction.
10 . The device of claim 9 , wherein in a second cross-sectional side view defined by the vertical direction and a second horizontal direction perpendicular to the first horizontal direction, the metal-containing gate electrode component is surrounded by the gate dielectric component in less than 360 degrees.
11 . The device of claim 9 , wherein the gate structure further includes an interfacial layer disposed between the gate dielectric component and the channel component in the first cross-sectional side view, the interfacial layer containing a metal germanium oxide, a metal silicon oxide, or a metal germanium silicon oxide.
12 . The device of claim 11 , wherein a portion of a side surface of the channel component extends to at least one of the first spacer or the second spacer.
13 . The device of claim 11 , wherein a portion of a bottom surface of the first spacer extends to a top surface of the interfacial layer in the first cross-sectional side view.
14 . The device of claim 9 , wherein a dimension of the channel component is greater than a dimension of the gate structure in the vertical direction.
15 . A device, comprising:
a channel layer;
a gate dielectric layer located laterally adjacent to the channel layer in a cross-sectional side view;
a gate electrode layer that is surrounded by the gate dielectric layer in the cross-sectional side view;
an interfacial layer disposed between the channel layer and the gate dielectric layer in the cross-sectional side view; and
a source/drain disposed above or below the channel layer in the cross-sectional side view;
a first spacer disposed above the gate dielectric layer in the cross-sectional side view;
a second spacer disposed below the gate dielectric layer in the cross-sectional side view;
a third spacer disposed above the first spacer in the cross-sectional side view;
a dummy material disposed below the second spacer in the cross-sectional side view; and
a dielectric component that extends to side surfaces of: the first spacer, the second spacer, the third spacer, the dummy material, and the gate dielectric layer.
16 . The device of claim 15 , further comprising a dielectric wherein at least one of the first spacer, the second spacer, or the third spacer is disposed laterally adjacent to the source/drain in the cross-sectional side view.
17 . The device of claim 15 , wherein:
the cross-sectional side view corresponds to a first vertical plane defined by a first horizontal direction and a vertical direction;
the gate electrode layer is surrounded by the gate dielectric layer in 360 degrees in the cross-sectional side view; and
in a different cross-sectional side view that corresponds to a second vertical plane defined by a second horizontal direction and the vertical direction, the gate electrode layer is surrounded by the gate dielectric layer in less than 360 degrees.
18 . The device of claim 17 , further comprising a conductive contact, wherein:
the conductive contact extends to a side surface of the gate electrode layer in the different cross-sectional side view; and
in the different cross-sectional side view: a portion of a side surface of the gate dielectric layer extends to a portion of a side surface of the conductive contact.
19 . The device of claim 15 , wherein in the cross-sectional side view:
a top surface of the channel layer has a more elevated vertical position than a top surface of the gate dielectric layer; and
a bottom surface of the channel layer has a less elevated vertical position than a bottommost surface of the gate dielectric layer.
20 . The device of claim 15 , wherein a side surface of the gate dielectric layer is not aligned with the side surface of the first spacer or with the side surface of the second spacer.