Patent ID: 8937005
Filing Date: 2015-01-20
Classification: H01L

Abstract:
1. A method for forming an NMOS field effect transistor (FET) in a doped well of a substrate, the NMOS FET having a source and a drain, comprising: forming an epitaxial carbon-containing silicon layer in the doped well; implanting dopants to form an NMOS anti-punchthrough layer positioned below the carbon-containing silicon layer; implanting dopants in the epitaxial carbon-containing silicon layer to form an NMOS screen layer, the NMOS screen layer being positioned laterally between eventual positions of the source and the drain; annealing the substrate; following implanting of all dopants, depositing a substantially undoped epitaxial layer on the epitaxial carbon-containing silicon layer; and forming a plurality of isolation structures to define transistor regions.