III-V compound semiconductor channel material formation on mandrel after middle-of-the-line dielectric formation

摘要

A method is provided in which a III-V compound semiconductor channel material is grown from at least one exposed sidewall of a semiconductor mandrel that is present in an NFET device region. The III-V compound semiconductor channel material is grown after formation of any PFET devices and after formation of a middle-of-the-line (MOL) dielectric material within the NFET device region.

主权项

1. A method of forming a semiconductor structure, said method comprising:
providing, in an NFET device region, at least one sacrificial gate structure straddling over a portion of at least semiconductor material portion; forming a source/drain structure from exposed sidewalls of each semiconductor material portion; removing said at least one semiconductor material portion not protected by said at least one sacrificial gate structure, while maintaining at least a semiconductor mandrel beneath each sacrificial gate structure, each semiconductor mandrel comprises a remaining portion of said semiconductor material portion; forming a middle-of-the-line (MOL) dielectric material laterally surrounding each sacrificial gate structure and atop each source/drain structure, wherein said MOL dielectric material has a topmost surface that is coplanar with each sacrificial gate structure; removing each sacrificial gate structure to provide a cavity, said cavity exposing at least one sidewall of each semiconductor mandrel; forming a III-V compound semiconductor channel material from said at least one sidewall of each semiconductor mandrel; removing each semiconductor mandrel to provide a gate cavity; and forming a functional gate structure in each gate cavity.