Fin Field Effect Transistor (FINFET) Device and Method for Forming the Same

A method for forming a fin field effect transistor (FinFET) device structure, comprising:

• providing a substrate;
• forming a fin structure above the substrate;
• forming a gate stack structure over a central portion of the fin structure;
• forming gate sidewall spacers on a top surface and sidewalls of the gate stack structure and forming fin sidewall spacers on a top surface and sidewalls the fin structure;
• removing a top portion of gate sidewall spacers and a top portion of the fin sidewall spacers to expose a top portion of the gate stack structure and a top portion of the fin structure;
• removing a portion of the fin sidewall spacers, wherein the fin sidewall spacers have a second height;
• recessing a portion of the fin structure to form a trench;
• and
• epitaxially growing a epitaxial structure from the trench, wherein the epitaxial structure is formed over the fin structure, and wherein the epitaxial structure has a first height (Ht1) and the first height is greater than the second height (H2), and wherein the epitaxial structure has a rhombus-like upper portion and a column-like lower portion, wherein the rhombus-like upper portion is entirely above a top of the fin sidewall spacers, and a junction between the rhombus-like upper portion and the sidewall of a column-like lower portion is higher than the top of the fin sidewall spacers, and further wherein a bottom surface of the column-like lower portion is level with a bottom surface of the fin sidewall spacers.

A method comprising:

• forming fin sidewall spacers on sidewalls of a semiconductor fin structure;
• recessing a portion of the semiconductor fin structure to form a recess between the fin sidewall spacers;
• epitaxially growing a column-like epitaxial structure within the recess;
• and
• epitaxially growing the epitaxial structure to extend above the recess, wherein the epitaxial structure forms a rhombus-like portion above the recess and above a topmost surface of the fin sidewall spacers, wherein a junction between the rhombus-like portion and the column-like epitaxial structure is above a topmost surface of the fin sidewall spacers.