CPC H10D 30/6211 (2025.01) [H01L 21/02057 (2013.01); H01L 21/26513 (2013.01); H01L 21/324 (2013.01); H01L 21/76224 (2013.01); H01L 21/76229 (2013.01); H01L 23/544 (2013.01); H10D 30/024 (2025.01); H10D 30/797 (2025.01); H10D 62/115 (2025.01); H10D 62/235 (2025.01); H10D 62/834 (2025.01); H01L 2223/54426 (2013.01); H01L 2223/54453 (2013.01)] | 20 Claims |
1. A device comprising:
a fin structure over a substrate, wherein the fin structure comprises:
a bottom portion protruding from the substrate; and
a top portion over the bottom portion, wherein a composition of the bottom portion is different from a composition of the top portion, and an interface between the bottom portion and the top portion comprises oxygen and has an oxygen concentration lower than about 1.E+19 atoms/cm3;
a gate structure covering the fin structure; and
a first source/drain epitaxial structure and a second source/drain epitaxial structure over the top portion of the fin structure and on opposite sides of the gate structure.
|