Semiconductor Structures and Manufacturing Methods Thereof

A method for manufacturing a semiconductor structure, comprising:

• forming an epitaxial layer on a semiconductor substrate;
• forming a protective layer on the epitaxial layer;
• forming a first patterned hard mask on the protective layer, the first patterned hard mask comprising an opening exposing a portion of the protective layer, and the opening surrounded by side surfaces of the first patterned hard mask;
• forming, by performing a first implantation through the first patterned hard mask, a first doped region in a portion of the epitaxial layer covered by the exposed portion of the protective layer, the first doped region being formed at a position below a corner of the exposed portion of the protective layer;
• forming a second patterned hard mask on the side surfaces of the first patterned hard mask;
• forming a second doped region in the portion of the epitaxial layer by performing a second implantation through the second patterned hard mask, wherein the first doped region is located along a sidewall of the second doped region and partially overlaps with the second doped region;
• forming a third patterned hard mask surrounding the second patterned hard mask;
• and
• forming a third doped region in the second doped region by performing a third implantation through the third patterned hard mask, a portion of the second doped region being between the first doped region and the third doped region.

A method for manufacturing a semiconductor structure, comprising:

• forming an epitaxial layer on a semiconductor substrate;
• forming a first patterned hard mask on a protective layer that is formed on the epitaxial layer, the first patterned hard mask comprising an opening exposing a portion of the protective layer, and the opening being surrounded by side surfaces of the first patterned hard mask;
• forming a first doped region and a second doped region in a portion of the epitaxial layer below the opening by performing a first implantation through the first patterned hard mask, the first doped region and the second doped region being formed at positions below two corners of the exposed portion of the protective layer;
• forming a second patterned hard mask on the side surfaces of the first patterned hard mask;
• forming a third doped region in the portion of the epitaxial layer by performing a second implantation through the second patterned hard mask, such that the first doped region and the second doped region are located along two opposing sidewalls of the third doped region and partially overlap with the third doped region;
• forming a third patterned hard mask surrounding the second patterned hard mask;
• and
• forming a fourth doped region in the third doped region by performing a third implantation through the third patterned hard mask, the fourth doped region being between the first doped region and the second doped region.