US Patent 10269958 Semiconductor device and method of fabricating the same

A semiconductor device includes first source/drain regions disposed at both sides of a first gate structure and including dopants of a first conductivity type, counter regions being in contact with upper portions of the first source/drain regions and under both end portions of the first gate structure, and first halo regions in contact with bottom surfaces of the first source/drain regions. The counter regions include dopants of a second conductivity type that is different from the first conductivity type. The first halo regions include dopants of the second conductivity type.