Self-Aligned Metal Gate for Multigate Device

A device comprising:

• a fin portion disposed between a first isolation feature and a second isolation feature, wherein the first isolation feature is different than the second isolation feature;
• a first dielectric fin disposed over the first isolation feature and a second dielectric fin disposed over the second isolation feature, wherein the first dielectric fin is different than the second dielectric fin;
• and
• a multigate device having a channel layer, a metal gate that wraps a portion of the channel layer, and source/drain features, wherein:
• the channel layer extends along a first direction between the source/drain features and along a second direction between the first dielectric fin and the second dielectric fin, the second direction being different than the first direction, and
• the metal gate is disposed between and separates the channel layer from the second dielectric fin.

A method comprising:

• forming a multigate device having a channel layer, a metal gate that wraps a portion of the metal gate, and source/drain features over a substrate, wherein the channel layer extends along a first direction between the source/drain features;
• and
• forming a first dielectric fin and a second dielectric fin over the substrate, wherein:
• the channel layer extends along a second direction between the first dielectric fin and the second dielectric fin, wherein the second direction is different than the first direction,
• the metal gate is disposed between the channel layer and the second dielectric fin, and
• the first dielectric fin is different than the second dielectric fin.