The invention relates to a method of bio-metric identification of persons according to the hand, by which the shape of the hand is scanned, evaluated and compared with the database of hand shapes, whereas the three-dimensional shape of the hand is scanned, this is analysed and a three-dimensional model of the hand is created, which is compared with the database of three-dimensional models of hand. The high-frequency location devices may also be used to identify the contents andor routing information for material being moved within a facility. To this end, the invention provides a test structure comprised of a systematic tow of a number of different depth trenches that are made in the wafer. A closing portion for closing the gap over the opening is formed.