A semiconductor device structure comprises a plurality of vertical layers and a plurality of conductive elements wherein the vertical layers and plurality of conductive elements co-operate to function as at least two active devices in parallel. The semiconductor device structure may also comprise a plurality of horizontal conductive elements wherein the structure is arranged to support at least two concurrent current flows, such that a first current flow is across the plurality of vertical conductive elements and a second current flow is across the plurality of horizontal conductive elements.