c.DIFF Diffusion Furnace

centrotherm Solar Cell Diffusion Furnace c.DIFF
c.DIFF Diffusion Furnace in Production
c.DIFF Diffusion Process Boat

Tube furnace for c-Si solar cell diffusion, oxidation and annealing processes

Drawing on more than 30 years of experience, centrotherm ranks as one of the world’s leading suppliers of tube furnaces for diffusion and oxidation processes in the semiconductor and PV industries.

The c.DIFF diffusion furnace meets the diverse spectrum of solar cell mass production demands and also delivers outstanding reproducibility results in the generation of emitters thanks to high process security. The centrotherm POCl3 diffusion process delivers outstanding and residue-free gas phase diffusion results as well as reliable realization of high emitter resistance.

The high flexibility of the batch-type tube furnace, which accommodates varying production capacity utilization and process variations, is yet another key benefit. c.DIFF is available in a variety of versions to ensure compatibility with the specific process requirements, capacities and degrees of automation.

Moreover, the ability to separately control the individual process tubes ensures continuous operation - even while maintenance work is being performed or in case of individual tube shut down.


  • Diffusion on both wafer sides (extended gettering effect of phosphorus improves material quality)
  • High availability thanks to redundancy
  • Maximum purity (residue-free gas phase diffusion)
  • Configuration based on production capacity possible (number of process tubes, optional back-to-back lading)
  • Fully automatic boat transportation guarantees maximum tube capacity utilization
  • The modular design facilitates installation and start-up and enables the integration into existing production lines
  • Up to 5 quartz tubes can be operated independently of each other
  • Water cooling system prevents thermal interference between different tubes
  • Minimized production environment heat load and small footprint reduce the overall cost of ownership


  • Diffusion (POCl3, BBr3, BCl3)
  • Annealing
  • Wet and dry Oxidation (optional: DCE, HCl)
  • Further processes upon request