A semiconductor device includes a substrate; a fin structure formed on a substrate; and a gate feature formed over the fin structure, the gate feature comprising a gate dielectric layer, wherein the gate dielectric layer traverses the fin structure to overlay a central portion of the fin structure and opposite side portions of the fin structure that are located in respective undercuts formed in respective portions of a dielectric layer located adjacent to opposite sidewalls of the gate feature, wherein the undercuts extend beyond respective sidewalls of the gate feature and away from the central portion of the fin structure.

Semiconductor devices having improved gate electrode structures and methods of forming the same are disclosed. In an embodiment, a semiconductor device includes a gate structure over a semiconductor substrate, the gate structure including a high-k dielectric layer; an n-type work function layer over the high-k dielectric layer; an anti-reaction layer over the n-type work function layer, the anti-reaction layer including a dielectric material; a p-type work function layer over the anti-reaction layer, the p-type work function layer covering top surfaces of the anti-reaction layer; and a conductive cap layer over the p-type work function layer.

Multi-gate devices and methods for fabricating such are disclosed herein. An exemplary method includes forming a gate dielectric layer around first channel layers in a p-type gate region and around second channel layers in an n-type gate region. Sacrificial features are formed between the second channel layers in the n-type gate region. A p-type work function layer is formed over the gate dielectric layer in the p-type gate region and the n-type gate region. After removing the p-type work function layer from the n-type gate region, the sacrificial features are removed from between the second channel layers in the n-type gate region. An n-type work function layer is formed over the gate dielectric layer in the n-type gate region. A metal fill layer is formed over the p-type work function layer in the p-type gate region and the n-type work function layer in the n-type gate region.

A semiconductor device includes a non-volatile memory. The non-volatile memory includes a first dielectric layer disposed on a substrate, a floating gate disposed on the dielectric layer, a control gate, a second dielectric layer disposed between the floating gate and the control gate and having one of a silicon oxide layer, a silicon nitride layer and multilayers of silicon oxide and silicon nitride, and an erase gate and a select gate. The erase gate and the select gate include a stack of a bottom polysilicon layer and an upper metal layer.

A semiconductor device and a method of manufacturing the same are disclosed. The semiconductor device includes semiconductor wires disposed over a substrate, a source/drain epitaxial layer in contact with the semiconductor wires, a gate dielectric layer disposed on and wrapping around each channel region of the semiconductor wires, a gate electrode layer disposed on the gate dielectric layer and wrapping around the each channel region, and dielectric spacers disposed in recesses formed toward the source/drain epitaxial layer.

A semiconductor device includes a semiconductor substrate, a plurality of semiconductor fins, a gate stack and an epitaxy structure. The semiconductor fins are present on the semiconductor substrate. The semiconductor fins respectively include recesses therein. The gate stack is present on portions of the semiconductor fins that are adjacent to the recesses. The epitaxy structure is present across the recesses of the semiconductor fins. The epitaxy structure includes a plurality of corners and at least one groove present between the corners, and the groove has a curvature radius greater than that of at least one of the corners.

A semiconductor device includes: an active fin disposed on a substrate; a gate structure overlapping the active fin; source/drain regions disposed on both sides of the gate structure and on the active fin; and contact structures respectively connected to the source/drain regions, wherein the gate structure includes: a pair of gate spacers spaced apart from each other to provide a trench; a first gate electrode disposed in the trench and extending along an upper surface and a lateral surface of the active fin; a second gate electrode disposed on the first gate electrode in the trench, wherein the first gate electrode is not disposed between the second gate electrode and the pair of gate spacers; and a gate insulating film disposed between the pair of gate spacers and interposed between the first gate electrode and the active fin.

A control gate electrode and a memory gate electrode of a memory cell of a non-volatile memory are formed in a memory cell region of a semiconductor substrate, and a dummy gate electrode is formed in a peripheral circuit region. Then, n.sup.+-type semiconductor regions for a source or a drain of the memory cell are formed in the memory cell region and n.sup.+-type semiconductor regions for a source or a drain of MISFET are formed in the peripheral circuit region. Then, a metal silicide layer is formed over the n.sup.+-type semiconductor regions but the metal silicide layer is not formed over the control gate electrode, the memory gate electrode, and the gate electrode. Subsequently, the gate electrode is removed and replaced with the gate electrode for MISFET, Then, after removing the gate electrode and replacing it with a gate electrode for MISFET, a metal silicide layer is formed over the memory gate electrode and the control gate electrode.

A tunneling field effect transistor device disclosed herein includes a substrate, a body comprised of a first semiconductor material being doped with a first type of dopant material positioned above the substrate, and a second semiconductor material positioned above at least a portion of the gate region and above the source region. The first semiconductor material is part of the drain region, and the second semiconductor material defines the channel region. The device also includes a third semiconductor material positioned above the second semiconductor material and above at least a portion of the gate region and above the source region. The third semiconductor material is part of the source region, and is doped with a second type of dopant material that is opposite to the first type of dopant material. A gate structure is positioned above the first, second and third semiconductor materials in the gate 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.