Semiconductor structure and method of manufacturing the same

A semiconductor structure, comprising:

• a substrate with an epi-layer;
• a first etch stop layer disposed over the substrate;
• an interlayer dielectric (ILD) structure;
• at least one contact plug disposed in the ILD structure and over the epi-layer, and comprising:
• a silicide cap having a U-shape cross section, disposed on the epi-layer, and comprising:
• a cap body disposed on the epi-layer;
• and
• a cap wall protruding from an edge of the cap body toward a direction opposite to the epi-layer and surrounding a lower portion of the conductive pillar, wherein a thickness of the cap wall is less than a thickness of the cap body;
• a conductive pillar disposed over the cap body of the silicide cap and partially surrounded by the cap wall of the silicide cap, wherein the conductive pillar is separated from the epi-layer by the cap body;
• a liner disposed over the first etch stop layer and surrounding the contact plug and comprising:
• a lower portion abutting the cap wall of the silicide cap and having a nitride material;
• and
• an upper portion abutting the conductive pillar and having an oxidized nitride material;
• and
• a second etch stop layer disposed over the ILD structure and surrounding a portion of the conductive pillar,
• wherein a top of the conductive pillar is substantially coplanar with a top of the second etch stop layer, and
• wherein a height of the upper portion of the liner is greater than or equal to a height of the lower portion of the liner.

A semiconductor structure, comprising:

• a substrate with an epi-layer;
• a first etch stop layer disposed over the substrate;
• an interlayer dielectric (ILD) structure;
• at least one contact plug disposed in the ILD structure and over the epi-layer, and comprising:
• a silicide cap disposed on the epi-layer, and comprising:
• a cap body disposed on the epi-layer;
• and
• a cap wall protruding from an edge of the cap body toward a direction opposite to the epi-layer and surrounding a lower portion of the conductive pillar, wherein a thickness of the cap wall is less than a thickness of the cap body;
• a conductive pillar disposed over the cap body of the silicide cap and partially surrounded by the cap wall of the silicide cap, wherein the conductive pillar is separated from the epi-layer by the cap body;
• a hybrid liner disposed over the first etch stop layer and surrounding the contact plug and comprising:
• a lower portion abutting the cap wall of the silicide cap;
• and
• an upper portion abutting the conductive pillar;
• and
• a second etch stop layer disposed over the ILD structure and surrounding a portion of the conductive pillar,
• wherein a top of the conductive pillar is substantially coplanar with a top of the second etch stop layer and is substantially coplanar with a top of the hybrid liner, and
• wherein a height of the upper portion of the hybrid liner is greater than or equal to a height of the lower portion of the hybrid liner.