Structure and formation method of fin-like field effect transistor

A semiconductor device structure, comprising:

• a first fin structure extending from a semiconductor substrate;
• a gate stack covering a portion of the first fin structure;
• a first epitaxially grown source/drain structure over the first fin structure;
• a second fin structure over the semiconductor substrate;
• a second epitaxially grown source/drain structure over the second fin structure;
• a first semiconductor protection layer the first epitaxially grown source/drain structure, wherein the first semiconductor protection layer has an atomic concentration of silicon greater than that of the first epitaxially grown source/drain structure, wherein the first semiconductor protection layer has a first terminal edge adjacent a support element and a second terminal edge adjacent a spacer element disposed on a sidewall of the gate stack;
• and
• a second semiconductor protection layer over the second epitaxially grown source/drain structure, wherein the second semiconductor protection layer has an atomic concentration of silicon greater than that of the second epitaxially grown source/drain structure.

A method of fabricating a semiconductor device structure, comprising:

• forming a first fin structure and a second fin structure over a semiconductor substrate;
• forming a first gate stack over a portion of the first fin structure and a second gate stack over a portion of the second fin structure;
• forming a first source/drain structure adjacent the first gate stack while masking a portion of the second fin structure;
• after forming the first source/drain structure, forming a first protection layer over the first source/drain structure;
• forming a second source/drain structure adjacent the second gate stack while masking the first source/drain structure;
• depositing a dielectric layer over the first source/drain structure and the second source/drain structure;
• and
• patterning the dielectric layer to form a contact hole over the first source/drain structure, wherein an exposed portion of the first protection layer within the contact hole is thinned.