Barrier layers in semiconductor devices

A method, comprising:

• forming a polysilicon structure on a substrate;
• performing a nitridation process to form a barrier layer on the polysilicon structure;
• forming a gate spacer on the barrier layer;
• forming a source/drain region adjacent to the barrier layer;
• performing an annealing process to densify the gate spacer;
• adjusting a height of the barrier layer;
• and
• replacing the polysilicon structure with a gate structure.

A device, comprising:

• a substrate;
• a fin structure disposed on the substrate;
• a gate structure disposed on the fin structure;
• a hydrogen free nitride layer disposed on the fin structure and sidewalls of the gate structure;
• a gate spacer layer on the hydrogen free nitride layer;
• and
• a source/drain region disposed on the fin structure and adjacent to the hydrogen free nitride layer.