Silicon

Silicon ribbed plates in a box

Silicon

With its high-temperature stability, resistance to a broad range of chemicals, excellent mechanical properties and its monocrystalline structure, silicon is a much used material in microsystems technology.

The large range of available micromachining technologies make structuring of silicon substrates to a very high degree of accuracy possible:

  • High aspect ratio structures (e.g. comb-drives, trenches, through holes) can be achieved by DRIE etching.

  • Batch-wise wet etching in alkaline solutions can be used for etching anisotropic structures such as cavities, using the monocrystalline nature of the material.

  • Thin film deposition and patterning of various materials (PZT layers, metal vias, bondpads, dielectric thin films) can be used to create functional structures/layers.

Silicon is the material of choice when it comes to fabrication and integration of sensors, electronic circuits and CMOS, for example in bioMEMS applications. It allows combining CMOS technology with MEMS technology and microfluidics, which are becoming essential traits of the newest labs-on-chips for health and life science applications.

The use of hybrid material combinations in highly functional devices is essential to this end. At Micronit, we can combine the machining of glass, polymers, as well as silicon, in order to choose the fitting material combination for your application.

Image: MEMS comb drive structure in silicon.

Silicon wafers

The Micronit MEMS foundry offers processing of silicon wafers with diameters of 150 mm and 200 mm.

  • Wafer thickness: 0.1mm-2mm (typically 675/725 µm for 150/200 mm).
  • Silicon on Insulator (SOI), and double-SOI (DSOI) wafers possible.
  • Resistivity: ranging from <.01 Ohm cm to intrinsic silicon.
  • Chemical inertness: relatively inert. Does not react with oxygen, water, and most acids. Does react with dilute alkalis and halogens.
  • Thermal conductivity: very high (especially compared to glass, which is thermally insulating). This enables increasing the density of on-chip components.
  • Surface roughness: Å range.
  • Autofluorescence: extremely low.
  • Transparent to IR wavelength range (refractive index: n = 3.38).

Are you working on a silicon device, such as a MEMS sensor, microfluidic structure, or hybrid device? Do you need CMOS post-processing services? Or would you like to discuss the best type of material for your project? Please, feel free to contact us directly. Our Sales and R&D teams will be happy to assist you!