Semiconductor device structure and methods of forming the same

A method, comprising:

• forming a fin structure from a substrate;
• forming a sacrificial gate stack over the fin structure;
• depositing a first gate spacer on the sacrificial gate stack;
• incorporating fluorine into the first gate spacer;
• depositing a second gate spacer on the first gate spacer;
• removing portions of the fin structure to expose a portion of the substrate;
• forming a source/drain region from the portion of the substrate;
• incorporating fluorine into the second gate spacer;
• removing the sacrificial gate stack;
• and
• incorporating additional fluorine into the first gate spacer.

A method, comprising:

• forming a fin structure from a substrate, wherein the fin structure comprises a first plurality of semiconductor layers and a second plurality of semiconductor layers;
• forming a sacrificial gate stack over the fin structure;
• depositing a gate spacer on the sacrificial gate stack;
• removing portions of the fin structure to expose a portion of the substrate;
• recessing the second plurality of semiconductor layers to form cavities;
• forming dielectric spacers in the cavities;
• forming a source/drain region from the portion of the substrate;
• removing the sacrificial gate stack and the second plurality of semiconductor layers;
• forming an interfacial layer on a portion of each of the first plurality of semiconductor layers;
• and
• incorporating fluorine into the dielectric spacers.