Fin end spacer for preventing merger of raised active regions

摘要

After formation of gate structures over semiconductor fins and prior to formation of raised active regions, a directional ion beam is employed to form a dielectric material portion on end walls of semiconductor fins that are perpendicular to the lengthwise direction of the semiconductor fins. The angle of the directional ion beam is selected to be with a vertical plane including the lengthwise direction of the semiconductor fins, thereby avoiding formation of the dielectric material portion on lengthwise sidewalls of the semiconductor fins. Selective epitaxy of semiconductor material is performed to grow raised active regions from sidewall surfaces of the semiconductor fins. Optionally, horizontal portions of the dielectric material portion may be removed prior to the selective epitaxy process. Further, the dielectric material portion may optionally be removed after the selective epitaxy process.

主权项

1. A method of forming a semiconductor structure comprising:
forming a semiconductor fin on a substrate, said semiconductor fin including a pair of lengthwise sidewalls and a widthwise sidewall; forming a dielectric material portion employing a directional ion beam that impinges on said widthwise sidewall along a beam direction that is contained within a vertical plane parallel to said pair of lengthwise sidewalls; forming at least one raised active region on physically exposed semiconductor surfaces of said semiconductor fin while said dielectric material portion is present on said widthwise sidewall; and removing said dielectric material portion selective to said semiconductor fin after said forming of said at least one raised active region.