US Patent 10535736 Fully strained channel

The present disclosure describes an exemplary method to form p-type fully strained channel (PFSC) or an n-type fully strained channel (NFSC) that can mitigate epitaxial growth defects or structural deformations in the channel region due to processing. The exemplary method can include (i) two or more surface pre-clean treatment cycles with nitrogen trifluoride (NF3) and ammonia (NH3) plasma, followed by a thermal treatment; (ii) a prebake (anneal); and (iii) a silicon germanium epitaxial growth with a silicon seed layer, a silicon germanium seed layer, or a combination thereof.