Wrap-around contacts including localized metal silicide

A semiconductor structure comprising:

• a semiconductor substrate including a first active region and a second active region;
• a plurality of parallel gate structures extending across the semiconductor substrate;
• a first field-effect transistor on the first active region, the first field-effect transistor comprising one of the gate structures, a channel region, and a first pair of epitaxial source/drain regions on opposite sides of the channel region, each epitaxial source/drain region being located between a first pair of the gate structures;
• a second field-effect transistor on the second active region, the second field-effect transistor comprising one of the gate structures, a channel region, and a second pair of epitaxial source/drain regions on opposite sides of the channel region, each epitaxial source/drain region being located between a second pair of the gate structures;
• a dielectric layer encasing the first field-effect transistor and the second field-effect transistor;
• a metal silicide liner wrapped around each of the source/drain regions;
• a conformal metal liner extending from and contiguous with each metal silicide liner, each conformal metal liner including a vertically extending portion confined between one of the first and second pairs of the gate structures and extending vertically above one of the source/drain regions, the first and second pairs of the gate structures extending vertically above the vertically extending portion of each conformal metal liner;
• and
• source/drain contact metal extending vertically through the dielectric layer and contacting the metal silicide liner.

A method of forming a semiconductor structure including wrap-around contacts, comprising:

• conformally depositing a metal liner on a monolithic structure, the monolithic structure including:
• first and second active regions;
• and
• field-effect transistors on the first and second active regions including gate structures and epitaxial source/drain regions;
• forming a metal silicide liner on and wrapping around the epitaxial source/drain regions from the metal liner;
• protecting the first and second active regions with a patterned block mask;
• selectively removing the metal liner from a region exposed by the patterned block mask between the first and second active regions;
• removing the patterned block mask;
• forming a protective mask on the monolithic structure such that the epitaxial source/drain regions are entirely beneath the top surface of the protective mask and portions of the metal liner above the first and second active regions are exposed;
• selectively removing the exposed portions of the metal liner above the first and second active regions;
• and
• removing the protective mask.

A method of forming a semiconductor structure including wrap-around contacts, comprising:

• obtaining a monolithic structure including:
• first and second active regions;
• field-effect transistors on the first and second active regions including gate structures, gate caps above the gate structures, gate sidewall spacers on sidewalls of the gate structures, and epitaxial source/drain regions between pairs of gate structures;
• and
• a contiguous liner including first liner portions on and wrapping around the epitaxial source/drain regions and a metal liner extending between the first and second active regions and over the gate caps and gate sidewall spacers;
• protecting the first and second active regions with a patterned block mask;
• selectively removing the metal liner from a region exposed by the patterned block mask between the first and second active regions;
• removing the patterned block mask;
• forming a protective mask on the monolithic structure such that the gate caps and top portions of the gate sidewall spacers extend above a top surface of the protective mask and the epitaxial source/drain regions are beneath the top surface of the protective mask;
• selectively removing the metal liner from the top portions of the gate sidewall spacers and the gate caps;
• and
• removing the protective mask.