Patent ID: 9059321
Filing Date: 2015-06-16
Classification: H01L

Abstract:
1. A method for forming a buried-channel field-effect transistor (FET) with a surface-channel FET, comprising: forming a dummy gate in at least a surface-channel region and a buried channel region of a substrate; depositing dielectric material around the dummy gates; doping a plurality of source and drain regions on the substrate with a dopant having a first type; forming a mask over at least one surface-channel region after removal of the dummy gate; epitaxially growing a doped shielding layer on at least one buried-channel region of the substrate after forming the mask, wherein the doped shielding layer has a second doping type opposite the first type, and wherein said doped shielding layer is formed after the plurality of source and drain regions are doped; removing the surface-channel region mask; forming a gate dielectric doped shielding layer; and forming a gate on the gate dielectric.