Buried channel field-effect transistors

摘要

Methods for forming a buried-channel field-effect transistor include doping source and drain regions on a substrate with a dopant having a first type; forming a doped shielding layer on the substrate in a channel region having a second doping type opposite the first type to displace a conducting channel away from a gate-interface region; forming a gate dielectric over the doped shielding layer; and forming a gate on the gate dielectric.

主权项

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.