Radio Frequency Plasma Cracker Source for the Generation of Ions from Oxygen or Reduced Oxygen Gases
The ion plasma source for nitrogen or other reduced nitrogen gases PCS-RF-IO is a fully UHV compatible component for most demanding MBE applications and surface modifications, suitable for a wide range of vacuum levels (UHV to HV). A RF current with 13.56 MHz is generated by the RF power supply and fed into a RF coil that surrounds the plasma tube in the source. The corresponding RF field is inductively coupled into the plasma tube and plasma is generated from the gas molecules inside the plasma discharge tube. High RF powers lead to very high power density in the plasma and thus highest possible cracking efficiencies. The charged particles are actively extracted from the plasma and accelerated towards the sample by application of an accelerating voltage. To avoid recombination of the ions and electrons, the source is equipped with metallic grids that have larger holes than the apertures in atom mode. The kinetic energy of the extracted ions is considerably higher than that of the neutral particles in atom mode, which allows implantation into deeper layers of the sample or sputtering of surface layers. The ion currents which can be achieved with the plasma sources are in the mA range and thus significantly higher than with other kinds of sources. It is suitable for cleaning or etching processes like reactive ion etching (RIE) or sputter deposition.
The source is fully bakeable with outstanding cooling from a full length water-jacket. With additional sets of the user-exchangeable extraction grids or aperture plates, the source can be easily reconfigured for reducing gases or as an atom source, downstream plasma source or hybrid source.
- Filamentless design permits operation with reactive gases
- High gas cracking efficiency
- Low operation pressures
- Unique coaxial design: For easy mounting on virtually all vacuum systems
- Unique integrated shutter and current monitor option
- Integral water cooling jacket for minimum system heat load
- Continously tunable from very small to very high atom fluxes
- Variable ion current (mA)
- Suitable for etching or sputter deposition.