Semiconductor device and method

A device comprising:

• a first semiconductor strip over a substrate, the first semiconductor strip comprising a first channel region;
• a second semiconductor strip over the substrate, the second semiconductor strip comprising a second channel region;
• a dielectric strip between the first semiconductor strip and the second semiconductor strip, a width of the dielectric strip decreasing along a first direction extending away from the substrate, wherein the dielectric strip comprises a plurality of dielectric layers and a void, wherein the dielectric layers in combination surround the void, each respective one of the dielectric layers surrounding a different portion of the void than other respective ones of the dielectric layers;
• and
• a gate structure extending continuously along the first channel region, across the dielectric strip, and along the second channel region.

A device comprising:

• a first source/drain region;
• a first channel region adjacent to the first source/drain region;
• a second source/drain region;
• a second channel region adjacent to the second source/drain region;
• a dielectric fin located between the first source/drain region and the second source/drain region in a first cross-section, the dielectric fin being further located between the first channel region and the second channel region in a second cross-section, the dielectric fin comprising one or more dielectric layers and a void surrounded by the one or more dielectric layers, a bottom of the void being wider than a top of the void in the first cross-section;
• and
• a gate structure extending continuously along the first channel region, across the dielectric fin, and along the second channel region in the second cross-section.