A method includes forming first, second, third, fourth, fifth, and sixth channel patterns on a semiconductor substrate; forming a first isolation wall interposing the first and second channel patterns, a second isolation wall interposing the third and fourth channel patterns, wherein the first isolation wall further continuously extends to interpose the fifth and sixth channel patterns; forming a first gate pattern extending across the first, second, third, and fourth channel patterns and the first and second isolation walls, and a second gate pattern extending across the fifth and sixth channel patterns and the first isolation wall from the top view, wherein the first, second, third, fourth, and sixth channel patterns respectively have first, second, third, fourth, and sixth dimensions in a lengthwise direction of the first gate pattern, and the sixth dimension is greater than the first, second, third, and fourth dimensions.

Semiconductor devices and fabrication methods are provided. In one example, a semiconductor device includes: a substrate, a fin formed on the substrate, a gate structure formed on the fin, a metal contact formed on the fin and adjacent to the gate structure. The fin extends along a first horizontal direction, the gate structure and the metal contact extend along a second horizontal direction, and the second horizontal direction is perpendicular to the first horizontal direction. The gate structure further includes a gate electrode coupled to the fin and a dielectric gate isolation section separated from the gate electrode. The dielectric gate isolation section includes a dielectric material. A portion of the dielectric gate isolation section is aligned with a portion of the metal contact adjacent and proximate to the dielectric gate isolation section in the first horizontal direction.

Embodiments described herein may be related to apparatuses, processes, systems, and/or techniques for integrating different materials into the channels for stacked transistor devices, for example in a CFET configuration, where the bottom device is an NMOS device and the top device is a PMOS device, or vice versa. Other embodiments may be described and/or claimed.

Integrated circuit structures having backside source or drain contact differentiated access are described. In an example, an integrated circuit structure includes first, second and third pluralities of horizontally stacked nanowires or fins, and first, second and third gate stacks. A first epitaxial source or drain structure is between the first plurality of horizontally stacked nanowires or fin and the second plurality of horizontally stacked nanowires or fin, the first epitaxial source or drain structure over a first conductive material having a first depth below the first epitaxial source or drain structure. A second epitaxial source or drain structure is between the second plurality of horizontally stacked nanowires or fin and the third plurality of horizontally stacked nanowires or fin, the second epitaxial source or drain structure over a second conductive material having a second depth below the second epitaxial source or drain structure, the second depth greater than the first depth.

A semiconductor cell comprises a top FET that contains a first set of silicon nanosheets and a bottom FET that contains a second set of silicon nanosheets. The top FET and bottom FET are in a stacked profile. The semiconductor cell comprises a top FET cutout region lateral to the first set of nanosheets and above a portion of the second set of nanosheets. The semiconductor cell also comprises a dielectric fill within the top FET cutout region.

Integrated circuit structures having differential epitaxial source or drain dent are described. For example, an integrated circuit structure includes a first sub-fin structure beneath a first stack of nanowires or fin. A second sub-fin structure is beneath a second stack of nanowires or fin. A first epitaxial source or drain structure is at an end of the first stack of nanowires of fin, the first epitaxial source or drain structure having no dent or a shallower dent therein. A second epitaxial source or drain structure is at an end of the second stack of nanowires or fin, the second epitaxial source or drain structure having a deeper dent therein.

A semiconductor device that has two transistors and a source/drain contact. The first transistor has a layer of semiconductor material that acts as a channel, a structure that serves as a gate and wraps around the semiconductor channel layer, and two epitaxy structures on either end of the semiconductor channel layer that function as the source and drain. The second transistor is situated above the first transistor and has similar components, including a semiconductor channel layer, gate structure, and source/drain epitaxy structures. The connection between the first and second source/drain epitaxy structures is made by a source/drain contact that passes through one of the second source/drain epitaxy structures. This contact is made up of a metal plug and a metal liner that lines the plug.

A semiconductor electrostatic discharge (ESD) protection circuit comprises an N diode for limiting negative going voltages with reference to ground (V.sub.SS) and a P diode for limiting positive going voltages with reference to a positive supply voltage (V.sub.DD). The N-diode is formed in a single P-well surrounded by an N-well ring. The P-diode is formed in a single N-well surrounded by a P-well ring. The N-diode comprises a plurality of N+ fingers, each N+ finger is surrounded by a P+ guard ring. The P-diode comprises a plurality of P+ fingers, each P+ finger surrounded by an N+ guard ring. The plurality of N+ fingers and P+ fingers are coupled to an input-output pad. The P+ guard rings are coupled to ground (V.sub.SS) and the N+ guard rings are coupled to the positive supply voltage (V.sub.DD).

A method includes forming a first transistor over a substrate, in which the first transistor includes first source/drain epitaxy structures; forming a second transistor over the first transistor, in which the second transistor includes second source/drain epitaxy structures; forming an opening extending through one of the second source/drain epitaxy structures and exposing a top surface of one of the first source/drain epitaxy structures; performing a first deposition process to form a first metal in the opening, in which a first void is formed in the first metal during the first deposition process; performing a first etching back process to the first metal until the first void is absent; and performing a second deposition process to form a second metal in the opening and over the first metal.

An electronic device includes a resistor with a drift region having majority carrier dopants of a first conductivity type and resistor terminals including first and second implanted wells with majority carrier dopants of the first conductivity type along laterally opposite sides of the drift region in a semiconductor layer, and a diode integrated with the resistor and including majority carrier dopants of a second conductivity type in the semiconductor layer adjacent one of the first and second implanted wells to limit a voltage across the resistor.