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Bosch Semiconductors for Automotive

Silicon epitaxy, doping and anneals

Silicon Epitaxy

Emerging from CMOS technology, silicon epitaxy is nowadays also at the heart of many MEMS products. State of the art pressure sensors are manufactured by growing a high quality single-crystal epitaxial layer over a porosified area, that reforms into a buried cavity (APSM technology). With inertial sensors, Bosch uses the epitaxial-reinforced poly-silicon (EpiPoly) as functional layer. Consequently this is available in a wide variations of processes including excellent thickness and stress control.

Silicon Epitaxy
20µm EpiPoly layer grown over patterned substrate (after CMP)

Technical Details

  • Epitaxial growth of 1µm – 100µm
  • Various deposition gases - silane, DCS, TCS
  • n-type and p-type in-situ doping, e.g. 1e15, can be increased up to 1e20 with ex-situ doping
  • In-line metrology of thickness, doping and stress
  • Stress-management for in- and out-of-plan stress
  • Thickness tolerance 1s < 1.5%

Doping

Dose: 1e11 to 1e16

Energy: 7 – 3,000 keV

  • Phosphorus
  • Arsen
  • Boron
  • Antimony
  • Nitrogen
  • More specialty materials for specific applications

Anneals

Bosch offers a variety of state of the art anneal furnaces, like ovens and RTAs.

Furnace
Furnace
  • Vertical and horizontal furnaces, up to 1,200°C
  • Metal anneals
  • UV hardening

Gases:

  • Forming gas
  • Pure hydrogen
  • Nitrogen
  • and others