Semiconductor structure and method for forming the same

A semiconductor structure, comprising:

• a gate structure formed over a substrate;
• a first source/drain (S/D) structure formed adjacent to the gate structure;
• a second S/D structure adjacent to the first S/D structure;
• and
• a dielectric wall between the first S/D structure and the second S/D structure, wherein:
• a bottommost surface of the first S/D structure is below a bottommost surface of the dielectric wall,
• the first S/D structure extends above a top surface of the dielectric wall, and the top surface of the dielectric wall is concave.

A semiconductor structure, comprising:

• a first source/drain (S/D) structure;
• a second S/D structure;
• a dielectric wall between a first portion of a sidewall of the first S/D structure and a first portion of a sidewall of the second S/D structure, wherein:
• a bottommost surface of the first S/D structure is below a bottommost surface of the dielectric wall,
• the dielectric wall comprises a liner dielectric layer and a core dielectric layer, and
• a bottommost surface of the core dielectric layer is above a topmost surface of the liner dielectric layer;
• and
• an etch stop layer between a second portion of the sidewall of the first S/D structure and a second portion of the sidewall of the second S/D structure.