SELECTIVE CONTACT ETCH FOR UNMERGED EPITAXIAL SOURCE/DRAIN REGIONS

摘要

A semiconductor structure includes a plurality of semiconductor material fins located on a surface of a substrate. At least one gate structure straddles over a portion of each semiconductor material fin. Unmerged source-side epitaxial semiconductor material portions are located on an exposed surfaces of each semiconductor material fin and on one side of each gate structure and unmerged drain-side epitaxial semiconductor portions are located on other exposed surfaces of each semiconductor material fin and on another side of each gate structure. An etch stop structure is located between each unmerged source-side and drain-side epitaxial semiconductor material portions. Each etch stop structure includes a bottom material portion that has a higher etch resistance in a specific etchant as compared to an upper material portion of the etch stop structure.

主权项

1. A semiconductor structure comprising:
a plurality of semiconductor material fins located on a surface of a substrate; at least one gate structure straddling over a portion of each semiconductor material fin of said plurality of semiconductor material fins; unmerged source-side epitaxial semiconductor material portions located on exposed surfaces of each semiconductor material fin and on one side of each gate structure; and unmerged drain-side epitaxial semiconductor portions located on other exposed surfaces of each semiconductor material fin and on another side of each gate structure; and an etch stop structure located between each unmerged source-side epitaxial semiconductor material portion and each unmerged drain-side epitaxial semiconductor material portion, wherein each etch stop structure comprises a bottom material portion and an upper material portion, said bottom material portion of said etch stop structure has a higher etch resistance in a specific etchant as compared to said upper material portion of said etch stop structure.