Deep Reactive Ion Etching

Bosch engineering is continuously optimizing the use of DRIE to avail the potential of this enabling process. Numerous combinations of mask layers, etchstopp, cleaning and characterization methods have been established. The MEMS community calls the resulting procedure the "Bosch Process".

Sacrificial etching

Isotropic etching of oxides or silicon is applied to realize movable MEMS structures or cavities.

KOH etching

This anisotropic process is available for high volume throughput. Established procedures utilize KOH wet etching as well as electrochemical KOH etching with etch stop on depleted pn-transitions.

Wafer bonding

Wafer bonding techniques can be offered with different requirements and specifications e.g. bonding material (glas frit, anodic bonding), enclosed pressure and medium, alignment accuracy.

Metallization

Depending on the workflow IC compatible metals or „exotic“ materials like Pt can be used in established procedures including sputtering and etching techniques.

Lithography

Depending on the workflow a variety of lithography tools can be implemented.

• Mask alignment: 5x1 stepper, 1x1 projection, Proximity, backside alignment, IR alignment
• Coaters/Developers: standard spin coating, spray coating, wafer edge coating

Thin film deposition

A huge portfolio of deposition methods is available.

• Dielectrica: CVD-oxides and -nitrides, thermal oxides, etc.
• Silicon: LPCVD-poly, epitaxial silicon, Epi-poly with numerous options for doping