Methods of Forming Epitaxial Structures in Fin-Like Field Effect Transistors

A method, comprising:

• providing a first fin structure on a semiconductor substrate in a first region for forming p-type metal-oxide-semiconductor (PMOS) devices and a second fin structure on the semiconductor substrate in a second region for forming n-type metal-oxide-semiconductor (NMOS) devices, wherein the first fin structure and the second fin structure are separated by isolation features;
• forming a first hard mask layer over the first fin structure, the second fin structure, and the isolation features;
• forming a first patterned etch mask layer over the second region thereby exposing the first region;
• removing a portion of the first fin structure to form a recessed first fin structure;
• forming a first source/drain feature on a top surface of the recessed first fin structure;
• removing the first hard mask layer from the second fin structure and the isolation features surrounding it;
• subsequent to removing the first hard mask layer, forming a second hard mask layer over the first source/drain feature, the second fin structure, and the isolation features;
• subsequent to forming the second hard mask layer, forming a second patterned etch mask over the first region thereby exposing the second region;
• removing a portion of the second fin structure to form a recessed second fin structure;
• forming a second source/drain feature on a top surface of the recessed second fin structure;
• and
• subsequent to forming the second source/drain feature, removing the second hard mask layer from the first fin structure and the isolation features surrounding it.

A method, comprising:

• providing a semiconductor substrate;
• forming a first fin structure and a second fin structure on the semiconductor substrate, wherein the first and the second fin structures are separated by isolation features;
• recessing the first fin structure;
• forming a first source/drain feature on the recessed first fin structure, wherein the first source/drain feature includes a p-type epitaxial semiconductor structure;
• subsequent to forming the first source/drain feature, recessing the second fin structure;
• and
• forming a second source/drain feature on the recessed second fin structure, wherein the second source/drain feature includes an n-type epitaxial semiconductor structure.