Institute of Microstructure Technology (IMT)

Dry Etching Cluster

Our Dry Etching Cluster consists of the Oxford RIE Plasmalab System 100 with ICP 380 source and the Oxford RIBE Ionfab 300. (RIE: Reactive Ion Etching, ICP: Inductively Coupled Plasma, RIBE: Reactive Ion Beam Etching). The Dry Etching Cluster is an advanced tool for micro- and nanomachining of various materials. The basic feature is a high frequency generator (RF) working at 13.56 Mhz, combined with a high vacuum chamber for wafers with a diameter of 4”. The power varies in the range of 1-2500 W. The gases used in our Dry Etching Cluster are among others SF6, CHF3, Cl2, BCl3 and HBr, allowing the structuring of a large variety of materials. For very shallow silicon designs in the nm range HBr is the preferred gas. Finally, for metal layer systems different Cl- und F-based RIE processes are available. Key features are:

  • Silicon etching via the cryo process (process temperatures are between -80 and -150 °C)
  • Production of highly vertical, highly parallel and smooth sidewalls
  • Critical lateral dimensions down to the range of 100 nm
  • Aspect ratios (ARs) up to 6 are possible.
  • Laser end point detection
  • Metal etching via RIBE

The Dry Etching Cluster belongs to the KNMF equipment. External users can apply for machine time by means of a proposal system at www.knmf.kit.edu.

 

Overview of the RIE/RIBE Cluster (Oxford Plasmalab RIE100-ICP380, Oxford Ionfab 3000Plus)

 

 
Auxetic bridge etched in silicon by DRIE (Silicon Cryo Process) with underetched oxide layer. Thickness of the silicon device: 1µm; width of the auxetic bars: approx. 300 nm.   Detail of a chiral auxetic structure (fabrication and dimensions see figure left). Application: exploration of the mechanical properties of in vivo growing cells.