Process Engineering

Plasmasensor - Planar sensor with stacked structure for measuring plasma parameters

Ref.-No. 5317

Keywords: Plasmasensor, Frequenz, Dichte, Plasma, Messung, Sensor, Regelung, Plasma sensor, frequency, density, measurement, control

Essential for the quality of such a process is the knowledge of the plasma state. Here, the plasma parameters are not only measured, but also used for the control of the process. Existing methods do not meet many industrial requirements and are complex and costly. The novel plasma sensor is based on the so-called active plasma resonance spectroscopy, whereby the sensor itself is flush-mounted in the wall of the reactor and thus does not affect the process. An integrated balun allows the sensor to be powered by a simple coaxial cable.


  • Simple setup
  • Easy installation in existing systems
  • Robust
  • Cost-efficient
  • Minimal influence on the plasma
  • Insensitive against additional dielectric coatings during process monitoring
  • Integrable into plasma control
  • High-temperature resistant realization is possible

Commercial Application

The plasma sensor can be used in most industrial plasma processes as long as no conductive layers are deposited. The sensor can measure the plasma parameters, in particular the plasma electron frequency, and provide the values for an active control and thus significantly improve the quality of the process. Since the sensor is integrated into the reactor wall, no great technical effort for installation is necessary.

Status Quo

A German patent application has been filed, further applications are possible. On behalf of the Ruhr-Universität Bochum, we offer interested companies the opportunity to license and develop the technology.

An invention of Ruhr-Universität Bochum.

Prof. Dr. Frank Entschladen
+49 208 9410520