Helios-tn

Coating Measurement of Solar Cells

Thickness and Refractive Index of Silicon Nitride

For wafer based solar cells the anti-reflective coating, surface passivation and diffusion barrier play an important role to achieve high solar cell efficiency and long term stability. Because of its excellent characteristics Silicon Nitride coating (a-SiNx:H) is widely used for this purpose. Process parameters like gas pressure and temperature of the cell during deposition have a strong influence on the layer thickness, colour and the optical constants n&k of Silicon Nitride. Traditionally it takes time and skills to obtain a precise coating distribution map to enable process optimization.

Measurement of Silicon Nitride

Using industry-proven spectrometer technology and proprietary measurement algorithms, Helios-tn combines speed, precise measurement and easy operation – all of which are needed to optimize processes at lowest cost and shortest line downtime.

Functions of Helios-tn

The Helios-tn systems are ideally suited for monitoring and controlling coating processes on silicon-based solar wafers. They offer highly precise measurements of layer thickness and optical constants (n&k) across single and multiple layers, with the ability to measure 2 – 3 parameters simultaneously. Available in inline or offline (manual or scan) versions, they provide fast and reliable results for production and laboratory use.