A fin field effect transistor (FinFET) is provided. The FinFET includes a substrate, a gate stack, and strained source and drain regions. The substrate has a semiconductor fin. The gate stack is disposed across the semiconductor fin. Moreover, the strained source and drain regions are located within recesses of the semiconductor fin beside the gate stack. Moreover, at least one of the strained source and drain regions has a top portion and a bottom portion, the bottom portion is connected to the top portion, and a bottom width of the top portion is greater than a top width of the bottom portion.

A method for manufacturing a semiconductor device includes forming a fin structure having a top surface and side surfaces. A mask layer is disposed over the top surface. A doping support layer is formed to cover part of the fin structure. A first impurity is introduced into a first region of the fin structure covered by the doping support layer, by implanting the first impurity into the doping support layer so that the implanted first impurity is introduced into the first region of the fin structure through the side surfaces.

A method for forming a three dimensional device. The method may include directing ions to an end surface of an extension region of a fin structure, the fin structure extending perpendicularly from a substrate plane and having a fin axis parallel to the substrate plane, wherein the ions have trajectories extending in a plane perpendicular to the substrate plane and parallel to the fin axis, wherein a portion of the fin structure is covered by a gate structure defining a channel region, and wherein the end surface is not covered by the gate structure.

An angled gas cluster ion beam is used for each sidewall and top of a fin (two applications) to form work-function metal layer(s) only on the sidewalls and top of each fin.

A method for manufacturing a semiconductor device includes providing a semiconductor structure having a substrate structure, multiple fins having a germanium layer, a dummy gate structure including sequentially a hardmask, a dummy gate, a dummy gate insulating material on the germanium layer, and spacers on opposite sides of the dummy gate structure and on a portion of the germanium layer. The method also includes forming an interlayer dielectric layer on the substrate structure covering the dummy gate structure, planarizing the interlayer dielectric layer to expose a surface of the dummy gate, removing the dummy gate and the dummy gate insulating material to expose a surface of the germanium layer, performing a silane impregnation process on the exposed surface of the germanium layer to introduce silicon to the germanium layer, and performing an oxidation process on the germanium layer to form an oxide layer comprising silicon and germanium.

A method includes forming a hard mask over an epitaxy layer of a substrate; forming a patterned mask over the hard mask; etching the hard mask and the epitaxy layer to form a trench in the epitaxy layer, in which a remaining portion of the hard mask covers a topmost surface of the epitaxy layer, and the trench exposes a sidewall of the epitaxy layer; forming a P-well region by directing p-type ion beams into the trench along an oblique direction that is non-parallel to a normal line of the topmost surface of the epitaxy layer, in which the topmost surface of the epitaxy layer is protected from the p-type ion beams by the remaining portion of the hard mask during directing the p-type ion beams into the trench; and after directing the p-type ion beams into the trench, forming a gate structure in the trench.

A method of fabricating a vertical fin-based field effect transistor (FET) includes providing a semiconductor substrate having a first surface and a second surface, the semiconductor substrate having a first conductivity type, epitaxially growing a first semiconductor layer on the first surface of the semiconductor substrate, the first semiconductor layer having the first conductivity type and including a drift layer and a graded doping layer on the drift layer, and epitaxially growing a second semiconductor layer having the first conductivity type on the graded doping layer. The method also includes forming a metal compound layer on the second semiconductor layer, forming a patterned hard mask layer on the metal compound layer, and etching the metal compound layer and the second semiconductor layer using the patterned hard mask layer as a mask exposing a surface of the graded doping layer to form a plurality of fins surrounded by a trench.

Non-planar transistors and methods of fabrication thereof are described. In an embodiment, a method of forming a non-planar transistor includes forming a channel region on a first portion of a semiconductor fin, the semiconductor fin having a top surface and sidewalls. A gate electrode is formed over the channel region of the semiconductor fin, and an in-situ doped semiconductor layer is grown on the top surface and the sidewalls of the semiconductor fin on opposing sides of the gate electrode using a selective epitaxial growth process. At least a part of the doped semiconductor layer is converted to form a dopant rich region.

A method of manufacturing a semiconductor structure, comprising providing a substrate; forming a fin structure over the substrate; depositing an insulation material over the fin structure; performing a plurality of ion implantation cycles in-situ with implantation energy increased or decreased stepwise; and removing at least a portion of the insulation material to expose a portion of the fin structure.

Memory devices, methods of manufacturing the same, and methods of accessing the same are provided. In one embodiment, the memory device may include a substrate, a back gate formed on the substrate, and a transistor. The transistor may include fins formed on opposite sides of the back gate on the substrate and a gate stack formed on the substrate and intersecting the fins. The memory device may further include a back gate dielectric layer formed on side and bottom surfaces of the back gate. The back gate dielectric layer may have a thickness reduced portion at a region facing the fins on one side of the gate stack.