A method for fabrication a field-effect-transistor includes forming a plurality of fin structures on a substrate, forming a gate structure across each fin structure and covering a portion of top and sidewall surfaces of the fin structure, forming a first doped layer, made of a first semiconductor material and doped with first doping ions, in each fin structure on one side of the corresponding gate structure, and forming a second doped layer, made of a second semiconductor material, doped with second doping ions, and having doping properties different from the first doped layer, in each fin structure on another side of the corresponding gate structure.

A method according to the present disclosure includes forming a fin-shaped structure protruding from a substrate, forming a gate structure intersecting the fin-shaped structure, forming a gate spacer on a sidewall of the gate structure, and forming a conductive feature above the fin-shaped structure. The gate spacer is laterally between the gate structure and the conductive feature. The method also includes depositing a dielectric layer over the gate structure and the conductive feature, performing an etching process, thereby forming an opening through the dielectric layer and exposing top surfaces of the conductive feature and the gate structure, recessing the gate spacers through the opening, thereby exposing the sidewall of the gate structure, and forming a contact feature in the opening, wherein the contact feature is in contact with the conductive feature and has a bottom portion protruding downward to be in contact with the sidewall of the gate structure.

A method for fabricating a semiconductor device includes first providing a substrate having a high-voltage (HV) region, a medium-voltage (MV) region, and a low-voltage (LV) region, forming a HV device on the HV region, and forming a LV device on the LV region. Preferably, the HV device includes a first base on the substrate, a first gate dielectric layer on the first base, and a first gate electrode on the first gate dielectric layer. The LV device includes a fin-shaped structure on the substrate, and a second gate electrode on the fin-shaped structure, in which a top surface of the first gate dielectric layer is even with a top surface of the fin-shaped structure.

A method for fabricating a semiconductor device includes first providing a substrate having a high-voltage (HV) region, a medium-voltage (MV) region, and a low-voltage (LV) region, forming a HV device on the HV region, and forming a LV device on the LV region. Preferably, the HV device includes a first base on the substrate, a first gate dielectric layer on the first base, and a first gate electrode on the first gate dielectric layer. The LV device includes a fin-shaped structure on the substrate, and a second gate electrode on the fin-shaped structure, in which a top surface of the first gate dielectric layer is lower than a top surface of the fin-shaped structure.

A method for forming the semiconductor device that includes forming a plurality of composite fin structures across a semiconductor substrate including an active device region and an isolation region. The composite fin structures may include a semiconductor portion over the active device region and a dielectric portion over the isolation region. A gate structure can be formed on the channel region of the fin structures that are present on the active regions of the substrate, and the gate structure is also formed on the dielectric fin structures on the isolation regions of the substrate. Epitaxial source and drain regions are formed on source and drain portions of the fin structures present on the active region, wherein the dielectric fin structures support the gate structure over the isolation regions.

A method for fabricating a semiconductor device comprises forming a first hardmask, a planarizing layer, and a second hardmask on a substrate. Removing portions of the second hardmask and forming alternating blocks of a first material and a second material over the second hardmask. The blocks of the second material are removed to expose portions of the planarizing layer. Exposed portions of the planarizing layer and the first hardmask are removed to expose portions of the first hardmask. Portions of the first hardmask and portions of the substrate are removed to form a first fin and a second fin. Portions of the substrate are removed to further increase the height of the first fin and substantially remove the second fin. A gate stack is formed over a channel region of the first fin.

A semiconductor device a method of forming the same are provided. The semiconductor device includes a substrate, a first isolation structure and a second isolation structure over the substrate, a semiconductor fin over the substrate and between the first isolation structure and the second isolation structure, and a third isolation structure extending through the semiconductor fin and between the first isolation structure and the second isolation structure. A top surface of the semiconductor fin is above a top surface of the first isolation structure and a top surface of the second isolation structure. The third isolation structure includes a first dielectric material and a second dielectric material over the first dielectric material. An interface between the first dielectric material and the second dielectric material is below the top surface of the first isolation structure and the top surface of the second isolation structure.

A method of forming a vertical fin field effect transistor (vertical finFET) with a self-aligned bottom source/drain, including forming a doped layer on a substrate, forming one or more vertical fins on the doped layer, forming a protective layer on the one or more vertical fins, wherein the protective layer has a thickness, and forming at least one isolation trench by removing at least a portion of the protective layer on the doped layer, wherein the isolation trench is laterally offset from at least one of the one or more vertical fins by the thickness of the protective layer.

A semiconductor device is provided including a fin active region on a substrate. The fin active region includes a lower region, a middle region, and an upper region. The middle region has lateral surfaces with a slope less steep than the lateral surfaces of the upper region. An isolation region is on a lateral surface of the lower region of the fin active region. A gate electrode structure is provided. A gate dielectric structure having an oxidation oxide layer and a deposition oxide layer, while having a thickness greater than half a width of the upper region of the fin active region is provided. The deposition oxide layer is between the gate electrode structure and the fin active region and the gate electrode structure and the isolation region, and the oxidation oxide layer is between the fin active region and the deposition oxide layer.

Resistance of a FINFET is reduced while performance of an element is prevented from being deteriorated due to an increase in stress, thereby performance of a semiconductor device is improved. When a memory cell formed on an upper side of a first fin and an n transistor formed on an upper side of a second fin are mounted on the same semiconductor substrate, the surface of the first fin having a source/drain region of the memory cell is covered with a silicide layer, and part of a source/drain region of the n transistor is formed of an epitaxial layer covering the surface of the second fin.