The present disclosure provides for semiconductor device structures and methods for forming semiconductor device structures, wherein a field-inducing structure is provided lower than an active portion of a fin along a height dimension of that fin, the height dimension extending in parallel to a normal direction of a semiconductor substrate surface in which the fin is formed. The field-inducing structure hereby implements a permanent field effect below the active portion. The active portion of the fin is to be understood as a portion of the fin covered by a gate dielectric.