An embodiment is a method including forming a first gate over a substrate, the first gate having first gate spacers on opposing sidewalls, forming a first hard mask layer over the first gate, forming a second hard mask layer over the first hard mask layer, the second hard mask layer having a different material composition than the first hard mask layer, forming a first dielectric layer adjacent and over the first gate, etching a first opening through the first dielectric layer to expose a portion of the substrate, at least a portion of the second hard mask layer being exposed in the first opening, filling the first opening with a conductive material, and removing the second hard mask layer and the portions of the conductive material and first dielectric layer above the first hard mask layer to form a first conductive contact in the remaining first dielectric layer.

A semiconductor device includes a gate disposed over a substrate; a source region and a drain region on opposing sides of the gate; and a pair of trench contacts over and abutting an interfacial layer portion of at least one of the source region and the drain region; wherein the interfacial layer includes boron in an amount in a range from about 510.sup.21 to about 510.sup.22 atoms/cm.sup.2.

A semiconductor device includes a gate disposed over a substrate; a source region and a drain region on opposing sides of the gate; and a pair of trench contacts over and abutting an interfacial layer portion of at least one of the source region and the drain region; wherein the interfacial layer includes boron in an amount in a range from about 510.sup.21 to about 510.sup.22 atoms/cm.sup.2.

A semiconductor device is disclosed. The device includes a source/drain feature formed over a substrate. A dielectric layer formed over the source/drain feature. A contact trench formed through the dielectric layer to expose the source/drain feature. A titanium nitride (TiN) layer deposited in the contact trench and a cobalt layer deposited over the TiN layer in the contact trench.

A semiconductor device includes an isolation layer, first and second fin structures, a gate structure and a source/drain structure. The isolation layer is disposed over a substrate. The first and second fin structures are disposed over the substrate, and extend in a first direction in plan view. Upper portions of the first and second fin structures are exposed from the isolation layer. The gate structure is disposed over parts of the first and second fin structures, and extends in a second direction crossing the first direction. The source/drain structure is formed on the upper portions of the first and second fin structures, which are not covered by the first gate structure and exposed from the isolation layer, and wraps side surfaces and a top surface of each of the exposed first and second fin structures. A void is formed between the source/drain structure and the isolation layer.

A semiconductor device includes a semiconductor substrate defining a major surface. The device further includes a first region including at least a first pillar of a first conductivity type extending in a vertical orientation with respect to the major surface. The device further includes a second region of the first conductivity type. The first pillar includes a higher doping concentration than the second region. The device further includes a Schottky contact coupled to the second region.

A semiconductor device with reinforced gate spacers and a method of fabricating the same. The semiconductor device includes low-k dielectric gate spacers adjacent to a gate structure. A high-k dielectric material is disposed over an upper surface of the low-k dielectric gate spacers to prevent unnecessary contact between the gate structure and a self-aligned contact structure. The high-k dielectric material may be disposed, if desired, over an upper surface of the gate structure to provide additional isolation of the gate structure from the self-aligned contact structure.

The present invention relates generally to semiconductor devices and more particularly, to a structure and method of forming a contact silicide on a source-drain (S-D) region of a field effect transistor (FET) having extensions by using an undercut etch and a salicide process. A method of forming a contact silicide extension is disclosed. The method may include: forming an undercut region below a dielectric layer and above a source-drain region, the undercut region located directly below a bottom of a contact trench and extending below the dielectric layer to a gate spacer formed on a sidewall of a gate stack; and forming a contact silicide in the undercut region, the contact silicide in direct contact with the source-drain region.

A method for forming a gate tie-down includes opening up a cap layer and recessing gate spacers on a gate structure to expose a gate conductor; forming inner spacers on the gate spacers; etching contact openings adjacent to sides of the gate structure down to a substrate below the gate structures; and forming trench contacts on sides of the gate structure. An interlevel dielectric (ILD) is deposited on the gate conductor and the trench contacts and over the gate structure. The ILD is opened up to expose the trench contact on one side of the gate structure and the gate conductor. A second conductive material provides a self-aligned contact down to the trench contact on the one side and to form a gate contact down to the gate conductor and a horizontal connection within the ILD over an active area between the gate conductor and the self-aligned contact.

Source/drain contact structures that exhibit low contact resistance and improved electromigration properties are provided. After forming a first contact conductor portion comprising a metal having a high resistance to electromigration such as tungsten at a bottom portion of source/drain contact trench to form direct contact with a source/drain region of a field effect transistor, a second contact conductor portion comprising a highly conductive metal such as copper or a copper alloy is formed over the first contact conductor portion.