Wet Etching

The wet chemical etching of glass and silicon substrates is one of the core competencies of Micronit. Additionally, Micronit GmbH offers etchings of various metals as well, such as Au, Cr, Cu, Ni, Ti etc. and the etching of non-conductors such as oxide and nitride.

Wet etching is a chemical etching process using a fluidic etchant. The advantage of the wet etching process for you as our customer is that it can be applied in batches therefore increasing the cost effectiveness.

Etching of Glass

Wet etching of glass is an isotropic etching technique done with hydro fluidic acid (HF). Isotropic means that the width of the structure on both sides is increased by the size of the etching depth. The corners are rounded off. The surface of the etch structures are corresponding to the glass used very smooth.

Technical Details

Technical Details

  • Etching of nanochannels
  • Deep channel etching (500 µm are possible)
  • Multiple depths on one wafer
  • Etching of different glass types like fused silica (quartz), borofloat, D263®
  • Aligned etching of fron- and backside
  • High tolerances of channels

Applications

Applications

  • Bio-MEMS, Lab-on-a-Chip, Point of Care
  • Microfluidic channels, such as micro mixers of glass
  • Microreactors of glass
  • Chromatography chips
  • Flow chemistry
  • Glass packages with single chambers on the wafer

Anisotrophic Etching (KOH, TMAH)

Anisotrophic etching using alkali hydroxides such as KOH, NaOH or amine-containing solutions such as TMAH etches silicon along the crystal plane. KOH is the most popular, having been in industrial use for decades. Depending on the temperature and concentration, different etch rates and surface roughness can be created. TMAH is used when oxide is to be maintained. The masking is done using a nitride deposition, which was lithogrphically structured before. Special KOH holders are used here.

Technical Details

Technical Details

Technical Details

  • Multi-Level etching
  • Aligned front and back side etching
  • Convex corner compensation
  • Exact crystal alignment
  • Masking with nitride

Applications

Applications

  • MEMS structures: pressure sensors
  • MESA-structures
  • Membrane fabrication
  • Silicon-cavities
  • V-grooves for fibre alignment
  • Through wafer connections
  • Microfluidic channels
  • Ink jet nozzles for MEMS
  • BioMEMS: carriers for cells or cell cultures

If you have any questions or requests, please call +49 (0) 231 88 68 077