Methods and apparatuses relate to implanting a surface of a semiconductor substrate with dopants, making undoped semiconductor material directly on the surface implanted with the dopants, and making a transistor with a transistor channel in the undoped semiconductor material, such that the transistor channel of the transistor remains undoped throughout manufacture of the integrated circuit.

A method for forming a fin on a substrate comprises patterning and etching a layer of a first semiconductor material to define a strained fin, depositing a layer of a second semiconductor material over the fin, the second semiconductor material operative to maintain the a strain in the strained fin, etching to remove a portion of the second semiconductor material to define a cavity that exposes a portion of the fin, etching to remove the exposed portion of the fin such that the fin is divided into a first segment and a second segment, and depositing an insulator material in the cavity, the insulator material contacting the first segment of the fin and the second segment of the fin.

A semiconductor device includes: a semiconductor substrate; a semiconductor layer that is located over the semiconductor substrate and includes a drain region, a source region, a drift region, and a channel region; an insulating film that is in contact with the semiconductor layer and is located over the channel region; a first interlayer insulating film that covers the insulating film; and a field plate that is located over the first interlayer insulating film, overlaps the drift region, and is electrically connected to the drain region.

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 method for forming a fin on a substrate comprises patterning and etching a layer of a first semiconductor material to define a strained fin, depositing a layer of a second semiconductor material over the fin, the second semiconductor material operative to maintain the a strain in the strained fin, etching to remove a portion of the second semiconductor material to define a cavity that exposes a portion of the fin, etching to remove the exposed portion of the fin such that the fin is divided into a first segment and a second segment, and depositing an insulator material in the cavity, the insulator material contacting the first segment of the fin and the second segment of the fin.

A method for forming a fin on a substrate comprises patterning and etching a layer of a first semiconductor material to define a strained fin, depositing a layer of a second semiconductor material over the fin, the second semiconductor material operative to maintain the a strain in the strained fin, etching to remove a portion of the second semiconductor material to define a cavity that exposes a portion of the fin, etching to remove the exposed portion of the fin such that the fin is divided into a first segment and a second segment, and depositing an insulator material in the cavity, the insulator material contacting the first segment of the fin and the second segment of the fin.

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 method of fabricating a semiconductor structure includes forming an isolation feature in a substrate, removing a portion of the isolation feature and a portion of the substrate underneath the removed portion of the isolation feature to form a trench in the substrate, and forming a trapping feature around a bottom portion of the trench. A first sidewall and a second sidewall of the trench are in direct contact with the isolation feature, and a bottom surface of the trench is below a bottom surface of the isolation feature.

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 semiconductor structure includes a substrate, a first power device and a second power device in the substrate, at least one isolation feature between the first and second power device, and a trapping feature adjoining the at least one isolation feature in the substrate.