FinFETs and techniques for controlling source and drain junction profiles in finFETs

摘要

Techniques and structures for shaping the source and drain junction profiles of a finFET are described. A fin may be partially recessed at the source and drain regions of the finFET. The partially recessed fin may be further recessed laterally and vertically, such that the laterally recessed portion extends under at least a portion of the finFET's gate structure. Source and drain regions of the finFET may be formed by growing a buffer layer on the etched surfaces of the fin and/or growing a source and drain layer at the source and drain regions of the fin. The lateral recess can improve channel-length uniformity along the height of the fin.

主权项

1. A finFET comprising:
a fin formed above a top surface of a substrate; a gate structure formed on at least portions of three sides of a channel region of the fin, said channel region having channel region sidewalls including a first sidewall portion farther from the substrate and extending perpendicular to the top surface of the substrate and a second sidewall portion nearer to the substrate and extending inwardly from the first sidewall portion in a direction under the gate structure; a source region formed in contact with the first and second sidewall portions of the channel region; a drain region formed in contact with the first and second sidewall portions of the channel region, wherein a first distance between source and drain junctions in the fin at the second sidewall portion is less than a second distance between source and drain junctions in the fin at the first sidewall portion.