Multi-gate semiconductor device and method for forming the same

A method for forming a multi-gate semiconductor device, comprising:

• forming a dummy gate structure over a channel region of a fin structure;
• forming a first insulating spacer along the dummy gate structure;
• forming a dielectric structure over a source/drain region of the fin structure;
• removing the first insulating spacer to form a first spacer trench between the dielectric structure and the dummy gate structure;
• filling a conductive spacer into the first spacer trench;
• removing the dummy gate structure to expose a sidewall of the conductive spacer and the channel region of the fin structure;
• patterning the channel region of the fin structure to form a plurality of nanostructures;
• forming a gate dielectric layer around the nanostructures;
• and
• forming a gate conductive structure over the gate dielectric layer.

A method for forming a multi-gate semiconductor device, comprising:

• providing a substrate comprising at least a fin structure and a dummy gate structure over the fin structure and the substrate;
• disposing an insulating spacer over sidewalls of the dummy gate structure, wherein portions of the fin structure are exposed from the dummy gate structure and the insulating spacer;
• forming a source/drain region in the portions of the fin structure exposed from the dummy gate structure and the insulating spacer;
• disposing a dielectric structure over the substrate;
• disposing a conductive spacer over the sidewalls of the dummy gate structure;
• removing the dummy gate structure to form a gate trench in the dielectric structure, wherein the conductive spacer is exposed from sidewalls of the gate trench;
• disposing at least a gate dielectric layer over a bottom of the gate trench after removing the dummy gate structure;
• and
• disposing a gate conductive structure in the gate trench, wherein sidewalls of the gate conductive structure are in contact with the conductive spacer.