Method for the formation of a FinFET device with epitaxially grown source-drain regions having a reduced leakage path

摘要

Elongated fins of a first semiconductor material are insulated from and formed over an underlying substrate layer (of either SOI or bulk type). Elongated gates of a second semiconductor material are then formed to cross over the elongated fins at channel regions, and the gate side walls are covered by sidewall spacers. A protective material is provided to cover the underlying substrate layer and define sidewall spacers on side walls of the elongated fins between the elongated gates. The first semiconductor material and insulating material of the elongated fins located between the protective material sidewall spacers (but not under the elongated gates) is removed to form trenches aligned with the channel regions. Additional semiconductor material is then epitaxially grown inside each trench between the elongated gates to form source-drain regions adjacent the channel regions formed by the elongated fins of the first semiconductor material located under the elongated gates.

主权项

1. A method, comprising:
forming a plurality of elongated fins of a first semiconductor material and an insulating material, the first semiconductor material being insulated from an underlying substrate material by the insulating material; forming an elongated gate of a second semiconductor material, said elongated gate extending to cross over the plurality of elongated fins; forming first sidewall spacers on side walls respectively of the elongated gate; forming a protective material covering the underlying substrate material and defining second sidewall spacers on side walls respectively of the plurality of elongated fins, the second sidewall spacers being located on a source side and a drain side of the elongated gate; removing the first semiconductor material and the insulating material of the plurality of elongated fins located on the source side and the drain side of the elongated gate to form a plurality of trenches, each trench being between a corresponding pair of the second sidewall spacers and exposing the underlying substrate material, the protective material comprising a plurality of portions separated from each other by the plurality of trenches, respectively; and epitaxially growing an additional semiconductor material including:
first portions located inside the plurality of trenches respectively, the first portions defining a plurality of source-drain regions respectively, each of the first portions being adjacent to a corresponding one of a plurality of channel regions, the plurality of channel regions being formed by the first semiconductor material of the plurality of elongated fins located under the elongated gate, respectively; anda second portion covering the protective material and connecting said first portions, wherein each of the first portions of the additional semiconductor material directly contacts the underlying substrate material and the insulating material interposed between the underlying substrate material and the corresponding one of the plurality of channel regions, and wherein each of the portions of the protective material is embedded in the additional semiconductor material and directly contacts the underlying substrate material.