REMOVAL OF SEMICONDUCTOR GROWTH DEFECTS

摘要

After semiconductor material portions and gate structures are formed on a substrate, a dielectric material layer is deposited on the semiconductor material portions and the gate structures. An anisotropic etch is performed on the dielectric material layer to form gate spacers, while a mask layer protects peripheral portions of the semiconductor material portions and the gate structures to avoid unwanted physical exposure of semiconductor surfaces. A selective epitaxy can be performed to form raised active regions on the semiconductor material portions. Formation of semiconductor growth defects during the selective epitaxy is prevented by the dielectric material layer. Alternately, a selective semiconductor deposition process can be performed after formation of dielectric gate spacers on gate structures overlying semiconductor material portions. Semiconductor growth defects can be removed by an etch while a mask layer protects raised active regions on the semiconductor material portions.

主权项

1. A semiconductor structure comprising:
at least one semiconductor material portion located on a substrate; a gate structure straddling said at least one semiconductor material portion, said gate structure including a pair of lengthwise sidewalls adjoined to each other through a pair of endwalls; a contiguous dielectric material liner contacting a top surface of said substrate and said pair of endwalls; and a dielectric spacer contiguously adjoined to, and having a same composition as, said contiguous dielectric material liner, and contacting a lower portion of one of said pair of lengthwise sidewalls, wherein a topmost edge of said dielectric spacer is located below a horizontal plane including a topmost surface of said gate structure.