A semiconductor device includes a substrate having a recess therein that is partially filled with at least two semiconductor active regions. The recess has sidewalls and a bottom that are sufficiently lined with corresponding substrate insulating layers that the at least two semiconductor active regions are electrically isolated from the substrate, which surrounds the sidewalls and bottom of the recess. A sidewall insulating layer is provided, which extends as a partition between first and second ones of the at least two semiconductor active regions, such that the first and second ones of the at least two semiconductor active regions are electrically isolated from each other. First and second gate electrodes are provided in the first and second active regions, respectively.

A semiconductor device includes a substrate and a semiconductor layer. The substrate includes a planar portion and a plurality of pillars on a periphery of the planar portion. The pillars are shaped as rectangular columns, and corners of two of the pillars at the same side of the planar portion are aligned in a horizontal direction or a direction perpendicular to the horizontal direction. The semiconductor layer is disposed over the planar portion and between the pillars.

A method of isolating sections of the channel layer in a SOI workpiece is disclosed. Rather than etching material to create trenches, which are then filled with a dielectric material, ions are implanted into portions of the channel layer to transform these implanted regions from silicon or silicon germanium into an electrically insulating material. These ions may comprise at least one isolating species, such as oxygen, nitrogen, carbon or boron. This eliminates various processes from the fabrication sequence, including an etching process and a deposition process. Advantageously, this approach also results in greater axial strain in the channel layer, since the channel layer is continuous across the workpiece.

Techniques for dielectric isolation in bulk nanosheet devices are provided. In one aspect, a method of forming a nanosheet device structure with dielectric isolation includes the steps of: optionally implanting at least one dopant into a top portion of a bulk semiconductor wafer, wherein the at least one dopant is configured to increase an oxidation rate of the top portion of the bulk semiconductor wafer; forming a plurality of nanosheets as a stack on the bulk semiconductor wafer; patterning the nanosheets to form one or more nanowire stacks and one or more trenches between the nanowire stacks; forming spacers covering sidewalls of the nanowire stacks; and oxidizing the top portion of the bulk semiconductor wafer through the trenches, wherein the oxidizing step forms a dielectric isolation region in the top portion of the bulk semiconductor wafer. A nanowire FET and method for formation thereof are also provided.

A bulk finFET with partial dielectric isolation is disclosed. The dielectric isolation is disposed underneath the channel, and essentially bounded by the channel, such that it does not extend laterally beyond the channel under the source and drain regions. This allows increased volume of SiGe source and drain stressor regions placed adjacent to the channel, allowing for a more strained channel, which improves carrier mobility. An N+ doped silicon region is disposed below the dielectric isolation and extends laterally beyond the channel and underneath the stressor source and drain regions, forming a reverse-biased p/n junction with the P+ doped source and drain SiGe stressor to minimize leakage currents from under the insulator.

A method for manufacturing a semiconductor-on-insulator (SeOI) chip comprises: a) providing a SeOI structure, b) building a plurality of isolated field effect transistors (FET) each comprising: —a preliminary gate above a channel region, the FETs from a first group having a first preliminary gate length and the FETs from a second group having a smaller second preliminary gate length, —a source region and a drain region, and —a source electrode and a drain electrode, c) removing at least the preliminary gates of the FETs from the second group, leaving access to channel regions of the FETs, d) thinning a top layer in channel regions of the FETs from the second group, the top layer in channel regions of the first group of FETs having a different thickness, and e) forming functional gates simultaneously on channel regions of the FETs whose preliminary gates were removed.

Techniques for dielectric isolation in bulk nanosheet devices are provided. In one aspect, a method of forming a nanosheet device structure with dielectric isolation includes the steps of: optionally implanting at least one dopant into a top portion of a bulk semiconductor wafer, wherein the at least one dopant is configured to increase an oxidation rate of the top portion of the bulk semiconductor wafer; forming a plurality of nanosheets as a stack on the bulk semiconductor wafer; patterning the nanosheets to form one or more nanowire stacks and one or more trenches between the nanowire stacks; forming spacers covering sidewalls of the nanowire stacks; and oxidizing the top portion of the bulk semiconductor wafer through the trenches, wherein the oxidizing step forms a dielectric isolation region in the top portion of the bulk semiconductor wafer. A nanowire FET and method for formation thereof are also provided.

Semiconductor-on-insulator (SOI) field effect transistors (FETs) including body regions having different thicknesses may be formed on an SOI substrate by selectively thinning a region of a top semiconductor layer while preventing thinning of an additional region of the top semiconductor layer. An oxidation process or an etch process may be used to thin the region of the top semiconductor layer, and a patterned oxidation barrier mask or an etch mask may be used to prevent oxidation or etching of the additional portion of the top semiconductor layer. Shallow trench isolation structures may be formed prior to, or after, the selective thinning processing steps. FETs having different depletion region configurations may be formed using the multiple thicknesses of the patterned portions of the top semiconductor layer. For example, partially depleted SOI FETs and fully depleted SOI FETs may be provided.

Semiconductor-on-insulator (SOI) field effect transistors (FETs) including body regions having different thicknesses may be formed on an SOI substrate by selectively thinning a region of a top semiconductor layer while preventing thinning of an additional region of the top semiconductor layer. An oxidation process or an etch process may be used to thin the region of the top semiconductor layer, and a patterned oxidation barrier mask or an etch mask may be used to prevent oxidation or etching of the additional portion of the top semiconductor layer. Shallow trench isolation structures may be formed prior to, or after, the selective thinning processing steps. FETs having different depletion region configurations may be formed using the multiple thicknesses of the patterned portions of the top semiconductor layer. For example, partially depleted SOI FETs and fully depleted SOI FETs may be provided.

Semiconductor-on-insulator (SOI) field effect transistors (FETs) including body regions having different thicknesses may be formed on an SOI substrate by selectively thinning a region of a top semiconductor layer while preventing thinning of an additional region of the top semiconductor layer. An oxidation process or an etch process may be used to thin the region of the top semiconductor layer, and a patterned oxidation barrier mask or an etch mask may be used to prevent oxidation or etching of the additional portion of the top semiconductor layer. Shallow trench isolation structures may be formed prior to, or after, the selective thinning processing steps. FETs having different depletion region configurations may be formed using the multiple thicknesses of the patterned portions of the top semiconductor layer. For example, partially depleted SOT FETs and fully depleted SOI FETs may be provided.