PASSIVES HF-ELEMENT UND VERFAHREN ZUM BETREIBEN, ZUM HERSTELLEN UNDZUM BESTIMMEN VON CHARAKTERISTISCHEN EIGENSCHAFTEN DESSELBEN

NOVELTY - A MOS-type passive HF element has depleted interlayer charges at the semiconductor-insulator interface. DETAILED DESCRIPTION - A passive HF element, of conductor-insulator- semiconductor structure, has an arrangement (16a,16b) for producing depletion of interlayer charges in the interface region between the semiconductor substrate (14) and the overlying insulator (12). INDEPENDENT CLAIMS are also included for: (i) a method of operating the above passive HF element by dc voltage application between the conductor and the semiconductor substrate to achieve depletion of interlayer charges; (ii) a method of determining the characteristic properties of the above passive HF element by measuring the quadripole parameters for various depletion-causing dc voltages applied between the conductor and the semiconductor substrate and calculating the characteristic properties as a function of the applied dc voltage from the measured quadripole parameters; and (iii) a process for producing th e above passive HF element. Preferred Features: Depletion of the interlayer charges in the interface region (inversion layer) is achieved by dc voltage application between the conductor and the semiconductor substrate and/or by formation of a lightly doped region of certain doping type below the insulator. USE - As a passive HF element having a MOS structure, especially a coplanar line, integrated coil or interdigital capacitor. ADVANTAGE - The design provides a reduced mobile charge carrier density in the interface region and low electromagnetic wave attenuation for simple and effective improvement in the HF properties of the element compared with conventional passive HF devices. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a conductor-insulator-semiconductor structure of the passive HF element. Conductor 10 Insulator 12 Semiconductor 14 Voltage application leads 16a,b