A semiconductor device includes a first diffusion region of a first type with embedded therein, a second and a third diffusion region of a second type different from the first type. The second and third diffusion regions are more doped than the first region. The second and third diffusion regions are each connected to a respective contact. A dielectric layer covers at least an edge of the second and third diffusion regions, and the region in between the second and third diffusion regions. A piezoelectric layer is disposed on, over, adjacent to or in contact with the dielectric layer. A first structure is in a first soft ferromagnetic material and is arranged to perform mechanical stress on the piezoelectric layer in response to a magnetic field.