The present disclosure is directed to methods for the fabrication of buried layers in gate-all-around (GAA) transistor structures to suppress junction leakage. In some embodiments, the method includes forming a doped epitaxial layer on a substrate, forming a stack of alternating first and second nano-sheet layers on the epitaxial layer, and patterning the stack and the epitaxial layer to form a fin structure. The method includes forming a sacrificial gate structure on the fin structure, removing portions of the fin structure not covered by the sacrificial gate structure, and etching portions of the first nano-sheet layers. Additionally, the method includes forming spacer structures on the etched portions of the first nano-sheet layers and forming source/drain (S/D) epitaxial structures on the epitaxial layer abutting the second nano-sheet layers. The method further includes removing the sacrificial gate structure, removing the first nano-sheet layers, and forming a gate structure around the second nano-sheet layers.

The present disclosure relates to a semiconductor device and a method of forming the same, and the semiconductor device includes a substrate, a gate line and a stress layer. The substrate has a plurality of first fins protruded from the substrate. The gate line is disposed over the substrate, across the first fins, to further include a gate electrode and a gate dielectric layer, wherein the dielectric layer is disposed between the gate electrode layer and the first fins. The stress layer is disposed only on lateral surfaces of the first fins and on a top surface of the substrate, wherein a material of the stress layer is different from a material of the first fins.

A semiconductor device includes a plurality of active fins defined by an isolation layer on a substrate, a gate structure on the active fins and the isolation layer, and a gate spacer structure covering a sidewall of the gate structure. A sidewall of the gate structure includes first, second, and third regions having first, second, and third slopes, respectively. The second slope increases from a bottom toward a top of the second region. The second slope has a value at the bottom of the second region less than the first slope. The third slope is greater than the second slope.

An integrated circuit device with a substrate and a plurality of fins is provided where fin width is less than 11 nanometers, fin height is greater than 155 nanometers and spacing between any two neighboring fins is less than 30 nanometers and each fin is in non-collapsed state. An integrated circuit device with a substrate and a plurality of fins is provided where fin width is less than 15 nanometers, fin height is greater than 190 nanometers and spacing between any two neighboring fins is less than 30 nanometers and each fin is in non-collapsed state. A method for forming a fin-based transistor structure is provided where a plurality of fins on a substrate are pre-treated with at least one of a self-assembled monolayer, a non-polar solvent, and a surfactant. One or more of these treatments is to reduce adhesion and/or cohesive forces to prevent occurrence of fin collapse.

An electronic device including at least first and second superimposed transistors comprises at least a substrate; a first transistor including a portion of a first nanowire forming a first channel, and first source and drain regions in contact with ends of the first nanowire portion; and a second transistor including a portion of a second nanowire forming a second channel and having a greater length than that of the first channel, and second source and drain regions in contact with ends of the second nanowire portion such that the second transistor is arranged between the substrate and the first transistor. A dielectric encapsulation layer covers at least the second source and drain regions and such that the first source and drain regions are arranged at least partly on the dielectric encapsulation layer, and forms vertical insulating portions extending between the first and second source and drain regions.

A semiconductor structure is provided. The semiconductor structure includes a gate structure over a fin structure. The semiconductor structure also includes a source/drain structure in the fin structure and adjacent to the gate structure. The semiconductor structure also includes a first contact plug over the source/drain structure. The semiconductor structure also includes a first via plug over the first contact plug. The semiconductor structure also includes a dielectric layer surrounding the first via plug. The first via plug includes a first group IV element and the dielectric layer includes the first group IV element and a second group IV element.

Semiconductor devices and methods of forming the same include forming first recesses in a first stack of alternating sacrificial layers and channel layers. A first inner spacer sub-layer is formed in the first recesses from a first dielectric material. A second inner spacer sub-layer is formed in the first recesses from a second dielectric material, different from the first dielectric material. The sacrificial layers and the first inner spacer sub-layer are replaced with a gate stack in contact with the second inner spacer sub-layer.

In an embodiment, a method includes: forming a fin extending from a substrate; forming a first gate mask over the fin, the first gate mask having a first width; forming a second gate mask over the fin, the second gate mask having a second width, the second width being greater than the first width; depositing a first filling layer over the first gate mask and the second gate mask; depositing a second filling layer over the first filling layer; planarizing the second filling layer with a chemical mechanical polish (CMP) process, the CMP process being performed until the first filling layer is exposed; and planarizing the first filling layer and remaining portions of the second filling layer with an etch-back process, the etch-back process etching materials of the first filling layer, the second filling layer, the first gate mask, and the second gate mask at the same rate.

A method includes etching two source/drain regions over a substrate to form two source/drain trenches; epitaxially growing two source/drain features in the two source/drain trenches respectively; performing a cut process to the two source/drain features; and after the cut process, depositing a contact etch stop layer (CESL) over the two source/drain features.

The present disclosure provides one embodiment of a semiconductor structure. The semiconductor structure includes a substrate having a front side and a back side; a gate stack formed on the front side of the substrate and disposed on an active region of the substrate; a first source/drain feature formed on the active region and disposed at an edge of the gate stack; a backside power rail formed on the back side of the substrate; and a backside contact feature interposed between the backside power rail and the first source/drain feature, and electrically connecting the backside power rail to the first source/drain feature. The backside contact feature further includes a first silicide layer on the back side of the substrate and directly contacting a bottom surface of the first source/drain feature.