Method of manufacturing a semiconductor device and a semiconductor device

A semiconductor device, comprising:

• a first group of semiconductor channel structures vertically arranged above a first fin structure, each of which has a channel region;
• a first source/drain epitaxial layer connected to ends of the semiconductor channel structures of the first group and disposed above the first fin structure,
• a second group of semiconductor channel structures vertically arranged above a second fin structure, each of which has a channel region;
• and
• a second source/drain epitaxial layer connected to ends of the semiconductor channel structures of the second group and disposed above the second fin structure, wherein:
• the first fin structure is adjacent to the second fin structure with an isolation insulating layer interposed between the first and second fin structures,
• a bottom of the first source/drain epitaxial layer is separated from the first fin structure by a dielectric layer,
• a bottom of the second source/drain epitaxial layer is separated from the second fin structure by the dielectric layer, and
• no part of the dielectric layer is disposed between the first group of semiconductor channel structures and the first fin structure.

A semiconductor device, comprising:

• semiconductor channel structures vertically arranged and extending in a first direction, each of which has a channel region;
• and
• a source/drain epitaxial layer connected to ends of the semiconductor channel structures, wherein:
• the semiconductor channel structures and the source/drain region are disposed above a fin structure,
• a bottom of the source/drain epitaxial layer is separated from the fin structure by a dielectric layer,
• the dielectric layer is in contact with the fin structure and is not disposed between the semiconductor channel structures and the fin structure, and
• an upper surface of the fin structure in contact with the dielectric layer has a groove.