Methods of fabricating semiconductor devices having air-gap spacers

A method of fabricating a semiconductor device, comprising:

• forming a gate structure on a fin that protrudes from a semiconductor substrate;
• depositing disposable spacers on sidewalls of the gate structure;
• forming a source region and a drain region in the fin and at opposite sides of the gate structure;
• depositing an interlayer dielectric layer over the source region and the drain region;
• removing an upper portion of the gate structure to form a space between the disposable spacers;
• removing the disposable spacer to form a trench between the gate structure and the interlayer dielectric layer;
• and
• sealing the trench to form an air-gap spacer.

A method of fabricating a semiconductor device, comprising:

• forming a gate structure over a substrate;
• forming a disposable spacer and an inner sidewall spacer on a sidewall of the gate structure, wherein the inner sidewall spacer is closer to the gate structure than the disposable spacer;
• forming a source region and a drain region at opposite sides of the gate structure;
• depositing an interlayer dielectric layer around the disposable spacer;
• etching back the gate structure;
• removing the disposable spacer and a first portion of the inner sidewall spacer to form a trench between a second portion of the inner sidewall spacer and the interlayer dielectric layer;
• and
• forming a sealing spacer to fill a portion of the trench, wherein an air-gap is between the sealing spacer and the substrate.
• sealing the trench to form an air-gap spacer.