Gate contact structures disposed over active portions of gates and methods of forming such gate contact structures are described. For example, a semiconductor structure includes a substrate having an active region and an isolation region. A gate structure has a portion disposed above the active region and a portion disposed above the isolation region of the substrate. Source and drain regions are disposed in the active region of the substrate, on either side of the portion of the gate structure disposed above the active region. A gate contact structure is disposed on the portion of the gate structure disposed above the active region of the substrate.

A semiconductor component including: a semiconductor substrate; and a semiconductor device provided thereon, the device being a field-effect transistor that includes: a gate insulating film provided on the substrate; a gate electrode provided via the film; and a pair of source-drain regions provided to sandwich the electrode, the substrate including a patterned surface in a portion where the electrode is provided, the patterned surface of the substrate including a raised portion where the film is formed to cover a surface that lies on the same plane as a surface of the pair of source-drain regions, and the electrode is formed on a top surface of the film, and the patterned surface of the substrate including a recessed portion where the film is formed to cover surfaces of a groove formed toward the interior than the surface of the pair of source-drain regions, and the electrode is formed so as to fill the groove provided with the film.

Gate contact structures disposed over active portions of gates and methods of forming such gate contact structures are described. For example, a semiconductor structure includes a substrate having an active region and an isolation region. A gate structure has a portion disposed above the active region and a portion disposed above the isolation region of the substrate. Source and drain regions are disposed in the active region of the substrate, on either side of the portion of the gate structure disposed above the active region. A gate contact structure is disposed on the portion of the gate structure disposed above the active region of the substrate.

A semiconductor component including: a semiconductor substrate; and a semiconductor device provided thereon, the device being a field-effect transistor that includes: a gate insulating film provided on the substrate; a gate electrode provided via the film; and a pair of source-drain regions provided to sandwich the electrode, the substrate including a patterned surface in a portion where the electrode is provided, the patterned surface of the substrate including a raised portion where the film is formed to cover a surface that lies on the same plane as a surface of the pair of source-drain regions, and the electrode is formed on a top surface of the film, and the patterned surface of the substrate including a recessed portion where the film is formed to cover surfaces of a groove formed toward the interior than the surface of the pair of source-drain regions, and the electrode is formed so as to fill the groove provided with the film.

Aspects of the disclosure provide a semiconductor device. The semiconductor device includes a gate structure, a spacer structure and a source/drain structure that are formed on a surface of the semiconductor layer. The gate structure includes a dielectric structure, a metal structure and an insulator structure. The dielectric structure is formed on the surface of the semiconductor layer. A bottom of the metal structure contacts a top of the dielectric structure. The bottom of the insulator structure contacts a top of the metal structure and the insulator structure protrudes over the top of the metal structure. The spacer structure is configured to extend underneath the bottom of the insulator structure and contact a sidewall of the metal structure. The spacer structure is configured to space between the gate structure and the source/drain structure. The source/drain structure includes a source/drain doped structure, a silicide structure and a metal contact plug.

Partial self-aligned contact structures are provided. In one aspect, a method of forming a semiconductor device includes: patterning fins in a substrate; forming a gate(s) over the fins, separated from source/drains by first spacers, wherein a lower portion of the gate(s) includes a workfunction-setting metal, and an upper portion of the gate(s) includes a core metal between a metal liner; recessing the metal liner to form divots in the upper portion of the gate(s) in between the first spacers and the core metal; forming second spacers in the divots such that the first spacers and the second spacers surround the core metal in the upper portion of the gate(s); forming lower source/drain contacts in between the first spacers over the source/drains; recessing the lower source/drain contacts to form gaps over the lower source/drain contacts; and forming source/drain caps in the gaps. A semiconductor device is also provided.

A semiconductor structure and a method for forming same are provided, the forming method including: providing a base including a plurality of adjacent device unit regions, an initial device gate structure spanning a plurality of device unit regions being formed on the base; etching a portion of the initial device gate structure in thickness at a junction between the adjacent device unit regions to form a top opening; forming a spacer layer on a side wall of the top opening; etching a remainder of the initial device gate structure exposed from the spacer layer, and forming a bottom opening exposed from the base within the remainder of the initial device gate structure, the remainder of the initial device gate structure being used as a device gate structure; and forming an isolation structure within the top opening and the bottom opening. The spacer layer is configured to adjust a width of the bottom opening, so that the width of the bottom opening is less than a width of the top opening. Therefore, the width of the top opening can be increased properly to enlarge a process window in which the top opening is formed, thereby better implementing isolation between the adjacent device unit regions and improving integrity of the device gate structure, further helping improve performance of a transistor.

In fabricating metal-oxide-semiconductor field-effect transistors (MOSFETs), the implanting of lightly doped drain regions is performed before forming gate regions with a physical gate length that is associated with a reference channel length. The step of implanting lightly doped drain regions includes forming an implantation mask defining the lightly doped drain regions and an effective channel length of each MOSFET. The forming of the implantation mask is configured to define an effective channel length of at least one MOSFET that is different from the respective reference channel length.

A method includes forming a dummy gate stack, forming a dielectric layer, with the dummy gate stack located in the dielectric layer, removing the dummy gate stack to form a opening in the dielectric layer, forming a metal layer extending into the opening, and etching back the metal layer. The remaining portions of the metal layer in the opening have edges lower than a top surface of the dielectric layer. A conductive layer is selectively deposited in the opening. The conductive layer is over the metal layer, and the metal layer and the conductive layer in combination form a replacement gate.

A semiconductor device includes a semiconductor substrate having a gate trench including of an upper trench and a lower trench. The upper trench is wider than the lower trench. A gate is embedded in the gate trench. The gate includes an upper portion and a lower portion. A first gate dielectric layer is between the upper portion and a sidewall of the upper trench. The first gate dielectric layer has a first thickness. A second gate dielectric layer is between the lower portion and a sidewall of the lower trench and between the lower portion and a bottom surface of the lower trench. The second gate dielectric layer has a second thickness that is smaller than the first thickness.