Contact Plugs for Semiconductor Device and Method of Forming Same

A method comprising:

• forming a gate over a semiconductor structure;
• forming a first dielectric layer over the gate and the semiconductor structure;
• forming a first opening extending through the first dielectric layer and exposing the gate;
• performing a first surface treatment process on sidewalls of the first opening;
• selectively forming a first barrier layer on a bottom of the first opening and not on the sidewalls of the first opening;
• and
• bottom-up filling the first opening with a first conductive material.

A method comprising:

• forming a first epitaxial source/drain region and a second epitaxial source/drain region over a semiconductor structure;
• forming a gate over the semiconductor structure and between the first epitaxial source/drain region and the second epitaxial source/drain region;
• forming a first dielectric layer over the gate, the first epitaxial source/drain region and the second epitaxial source/drain region;
• etching the first dielectric layer to form a first opening and a second opening in the first dielectric layer, the first opening exposing the first epitaxial source/drain region, the second opening exposing the gate;
• performing a surface treatment process on sidewalls of the first opening and sidewalls of the second opening;
• and
• filling the first opening and the second opening with a conductive material in a bottom-up manner.