Semiconductor structure and method for forming the same

A method for forming a semiconductor structure, comprising:

• growing a source/drain epitaxial structure over a substrate;
• forming a contact structure over the source/drain epitaxial structure;
• depositing a metal layer over the contact structure;
• depositing a first cap layer over the metal layer;
• forming an opening in the first cap layer and the metal layer;
• filling the opening with a first dielectric layer;
• patterning the first cap layer to form a via cap plug over the metal layer;
• removing the via cap plug over the metal layer;
• and
• forming a conductive structure over the metal layer.

A semiconductor structure, comprising:

• a gate structure over a substrate;
• a source/drain epitaxial structure formed on opposite sides of the gate structure;
• a contact structure formed over the source/drain epitaxial structure;
• a first dielectric layer formed over the gate structure;
• a metal layer formed in the first dielectric layer;
• a protection layer formed over the sidewalls and the bottom surface of the first dielectric layer;
• a second dielectric layer formed over the metal layer and the first dielectric layer;
• and
• a first conductive structure formed in the second dielectric layer in contact with the metal layer,
• wherein a bottom portion of the first conductive structure is surrounded by the protection layer and the second cap layer.