PECVD Graphite Boat
Anti-Reflective Coating and Passivation of Solar Cells

Batch-type system for passivation and nitride coating in c-Si solar cell processing

centrotherm is the world market leader in the field of Plasma Enhanced Chemical Vapor Deposition (PECVD) for passivation and anti-reflective coating processes in the manufacturing of c-Si solar cells.

centrotherm’s fully automated PECVD system combines high throughput with excellent process security and reproduction capabilities. The tube systems ensure the creation of an extremely efficient and homogeneous anti-reflective coating using a direct plasma deposition process, which is limited in scope and comprises only the wafers and graphite boats, whereas process tubes are only marginally affected by parasitic deposition. This dispenses with periodic reactor cleaning and increases equipment availability.

Thanks to its excellent process flexibility, the tube system is not only a perfect solution for nitride coating processes, but also for the realization of highly efficient solar cell concepts, such as PERC or PID free solar cells.

One of the noteworthy benefits of the tube system is its flexibility, which accommodates varying production capacity utilization loads and ensures that the system will operate continuously while maintenance work is being performed or individual process tubes are shut down. The system is available in numerous different versions and can be configured to meet the specific process and capacity requirements, as well as varying degrees of automation. The centrotherm PECVD system requires a comparatively small footprint and delivers the lowest overall cost of ownership in the segment thanks to the maximum utilization of process gases.


  • Excellent passivation characteristics
  • Integrated surface conditioning (good adhesion, no blistering)
  • Variable process sequences for multiple and graded layers
  • High availability thanks to redundancy and short cycle times
  • Up to 5 independently operated quartz tube reactor chambers
  • Fully automated boat transport
  • Water cooling system prevents thermal interference between different tubes
  • The modular design facilitates installation and start-up as well as the integration into existing production lines


  • Silicon Nitride (SiNx) PECVD
  • Silicon Oxide (SiOx) PECVD
  • Silicon Oxynitride (SiONx) PECVD
  • Aluminum Oxide (AlOx) PECVD
  • Multi-layer
  • Further processes upon request