Abstract: Tapered source and drain contacts for use in an epitaxial FinFET prevent short circuits and damage to parts of the FinFET during contact processing, thus improving device reliability. The inventive contacts feature tapered sidewalls and a pedestal where electrical contact is made to fins in the source and drain regions. The pedestal also provides greater contact area to the fins, which are augmented by extensions. Raised isolation regions define a valley around the fins. During source/drain contact formation, the valley is lined with a conformal barrier that also covers the fins themselves. The barrier protects underlying local oxide and adjacent isolation regions against gouging while forming the contact. The valley is filled with an amorphous silicon layer that protects the epitaxial fin material from damage during contact formation. A simple tapered structure is used for the gate contact.

Abstract: Silicon germanium regions are formed adjacent gates electrodes over both n-type and p-type regions in an integrated circuit. A hard mask patterned by lithography then protects structures over the p-type region while the silicon germanium is selectively removed from over the n-type region, even under remnants of the hard mask on sidewall spacers on the gate electrode. Silicon germanium carbon is epitaxially grown adjacent the gate electrode in place of the removed silicon germanium, and source/drain extension implants are performed prior to removal of the remaining hard mask over the p-type region structures.

Abstract: A method for selectively etching single-crystal silicon-germanium in the presence of single-crystal silicon, including a chemical etch based on hydrochloric acid in gaseous phase at a temperature lower than approximately 700° C.