FINFET CIRCUIT DEVICES WITH WELL ISOLATION

A method includes receiving a structure that includes a substrate including a first well region having a first dopant type and a second well region having a second dopant type that is opposite to the first dopant type; and fins extending above the substrate. The method further includes forming a patterned etch mask on the structure, wherein the patterned etch mask provides an opening that is directly above a first fin of the fins, wherein the first fin is directly above the first well region. The method further includes etching the structure through the patterned etch mask, wherein the etching removes the first fin and forms a recess in the substrate that spans from the first well region into the second well region; and forming a dielectric material between remaining portions of the fins and within the recess.