Method of manufacturing strained source/drain structures

A method comprising:

• forming a trench in a semiconductor substrate, the trench being adjacent to a channel region;
• forming a first structure in the trench, the first structure being in contact with a bottom surface and sidewalls of the trench, and the first structure having a first dopant with a first dopant concentration;
• and
• forming a second structure over the first structure and at least partially in the trench, the second structure having a second dopant with a second dopant concentration, and the second dopant having an electrical carrier type opposite to an electrical carrier type of the first dopant.

A method comprising:

• forming a gate structure over a substrate, the gate structure defining a channel region in the substrate;
• forming two trenches in the substrate, the two trenches being interposed by the channel region, and sidewalls and the bottom portions of the two trenches being along one or more {111} facets of the substrate;
• epitaxially growing a first structure in the trenches, the first structure extending along the sidewalls and bottom portions of the two trenches, and the first structure having a first dopant with a first dopant concentration;
• and
• epitaxially growing a second structure over the first structure, the second structure having a second dopant with a second dopant concentration, the second dopant having an electrical carrier type opposite to an electrical carrier type of the first dopant.