Method for forming a semiconductor device by recessing semiconductor layers and inner spacers

A method for forming a semiconductor device structure, comprising:

• forming a first fin structure and a second fin structure over a substrate, wherein each of the first fin structure and the second fin structure has a plurality of sacrificial layers and a plurality of semiconductor layers laid out in an alternating manner;
• partially removing the first fin structure and the second fin structure to form a plurality of recesses exposing side surfaces of the semiconductor layers and the sacrificial layers;
• forming a plurality of inner spacers covering the side surfaces of the sacrificial layers of the first fin structure and the second fin structure;
• forming n-type doped epitaxial structures on the side surfaces of the semiconductor layers of the first fin structure;
• recessing the semiconductor layers of the second fin structure after the n-type doped epitaxial structures are formed;
• trimming the inner spacers covering the side surfaces of the sacrificial layers of the second fin structure;
• and
• forming p-type doped epitaxial structures on the side surfaces of the semiconductor layers of the second fin structure.

A method for forming a semiconductor device structure, comprising:

• forming a plurality of sacrificial layers and a plurality of semiconductor layers laid out in an alternating manner;
• forming a plurality of inner spacers covering side surfaces of the sacrificial layers;
• forming a plurality of second sacrificial layers and a plurality of second semiconductor layers laid out in an alternating manner;
• forming a first epitaxial structure on side surfaces of the second semiconductor layer;
• recessing the semiconductor layers from side surfaces of the semiconductor layers after the inner spacers and the first epitaxial structure are formed;
• trimming the inner spacers after the recessing of the semiconductor layers;
• and
• forming a second epitaxial structure on the side surfaces of the semiconductor layers, wherein the second epitaxial structure and the first epitaxial structure have opposite conductivity type.