A method of producing a semiconductor substrate comprising at least one integrated magnetic flux concentrator, comprising the steps of: a) providing a semiconductor substrate having an upper surface; b) making at least one cavity in said upper surface; c) depositing one or more layers of one or more materials, including sputtering at least one layer of a soft magnetic material; d) removing substantially all of the soft magnetic material that is situated outside of the at least one cavity, while leaving at least a portion of the soft magnetic material that is inside said at least one cavity. A semiconductor substrate comprising at least one integrated magnetic flux concentrator. A sensor device or a sensor system, a current sensor device or system, a position sensor device or system, a proximity sensor device or system, an integrated transformer device or system.