THz Schottky Devices

Schottky-Dioden für den THz-Bereich

Prof. Dr. Eng. Dr. h. c. mult H. L. Hartnagel

Dr. Ing. O. Cojocari

Dr. Ing. C. Sydlo

Dipl. Ing. D. Schönherr


The development of Schottky devices for the THz-range is a key issue for atmospheric investigations and medical applications (e.g.detection of greenhouse gases, cancer detection). III/V compound semiconductors are used for these applications as they provide the required device speed and allow a high flexibility in the fabrication process (bandgap engineering). The research is focused on the development of a III/V-based Schottky device process (varistor, varactor) with emphasis on exellent noise properties, near-ideal diode characteristics and device reliability. The fabrication ranges from whisker-diodes to planar diodes for mixer- and multiplier application. For this purpose, the required technology is available including e.g. a MBE, lithography, evaporation and etching systems. The devices are designed applying state-of-the-art electro-magnetic modeling tools like CST Microwave studio.

  • Varistors and varactors
  • Mixer and Multiplier operation
  • Application in corner cubes
  • Test samples for process control
  • Process optimisation
  • Process control
  • Quasi-vertical design approach
  • Airbridge technology
  • Membrane technology
  • Technological complexity
  • Application in mixer and multipliers
  • Flip-chip mounting
  • Integration with filter structures
  • Reliability tests
  • MEMS
  • Material science


  • C. Sydlo and O. Cojocari and D. Schoenherr and T. Goebel and P. Meissner and H.L. Hartnagel. Fast THz detectors based on InGaAs Schottky Diodes – In Frequenz, 2008.
  • Daniel Schoenherr and Oleg Cojocari and Cezary Sydlo and Thorsten Goebel and Hans Ludwig Hartnagel and Peter Meissner. Broadband Schottky Diode Based THz Detector – WOCSDICE 2008.