Method for forming semiconductor device structure

A method for forming a semiconductor device structure, comprising:

• forming a semiconductor fin structure over a substrate;
• forming a dummy gate structure across the semiconductor fin structure;
• forming a dielectric material along the dummy gate structure and the semiconductor fin structure;
• removing a first portion of the dielectric material to expose a sidewall of the dummy gate structure while leaving a second portion of the dielectric material covering sidewalls of the semiconductor fin structure to form source/drain spacers;
• etching a source/drain region of the semiconductor fin structure to form a recess between the source/drain spacers;
• and
• epitaxially growing a source/drain feature from the recess.

A method for forming a semiconductor device structure, comprising:

• forming a semiconductor fin structure over a substrate;
• conformally forming an insulating material along the semiconductor fin structure and the substrate;
• forming a dielectric fin structure adjacent to the semiconductor fin structure and over the insulating material;
• recessing the insulating material to form a gap between the semiconductor fin structure and the dielectric fin structure;
• forming a first dielectric material over the semiconductor fin structure and the dielectric fin structure and filling the gap;
• etching a first portion of the first dielectric material over the semiconductor fin structure and the dielectric fin structure to form a source/drain spacer in the gap;
• etching an upper portion of the semiconductor fin structure thereby exposing a lower portion of the semiconductor fin structure;
• and
• forming a source/drain feature over the lower portion of the semiconductor fin structure.