Fin field effect transistors having heteroepitaxial channels

摘要

Disposable gate structures are formed over semiconductor material portions, and source and drain regions can be formed in the semiconductor material portions. After formation of a planarization dielectric layer, one type of disposable gate structure can be removed selective to at least another type of disposable gate structure employing a patterned hard dielectric mask layer. After recessing a surface portion of a body portion, a heteroepitaxial channel portion is formed on the remaining physically exposed portion of the body portion by selective epitaxy of a semiconductor material different from the semiconductor material of the remaining body portion. A plurality of types of heteroepitaxial channel portions can be formed in different types of semiconductor devices. Replacement gate structures can be formed in the gate cavities to provide field effect transistors having different threshold voltages.

主权项

1. A method of forming a semiconductor structure comprising:
providing a first semiconductor material portion and a second semiconductor material portion that include a first semiconductor material on a substrate; forming a first disposable gate structure straddling said first semiconductor material portion and a second disposable gate structure straddling said second semiconductor material; forming a planarization dielectric layer laterally surrounding said first disposable gate structure and said second disposable gate structure; removing said first disposable gate structure to form a gate cavity while said second disposable gate structure is not removed, wherein a region of said first semiconductor material portion is physically exposed within said gate cavity; forming an epitaxial semiconductor material portion comprising a second semiconductor material directly on a surface of said first semiconductor material within said gate cavity; removing said second disposable gate structure; and forming gate structures on said epitaxial semiconductor material portion and said second semiconductor material portion.