SiNA® – Antireflection coating

About 8 years ago, silicon nitride (SiN) coatings deposited by means of PECVD (Plasma Enhanced Chemical Vapor Deposition) were introduced as standard for the anti-reflection coating and passivation of silicon solar cells. At that, through the surface and volume passivation of the silicon wafer, a significant increase of the efficiency of the solar cells in a range of more than 10% is reached..

With the SiNA® plant series, Roth & Rau offers SiN coating plants for various capacity requirements from the pilot manufacture (< 5 MWp) up to the fully automatic mass production (up to 100 MWp). The plants work in the in-line mode where the silicon wafers are processed on flat carriers. The coating deposition is realized in a continuous process in a silane/ammonia plasma using plasma sources specifically developed for this process. Thanks to a careful process optimization and experiences of many years under production conditions, the SiN coatings show very good passivation properties and an excellent homogeneity of coating thickness and optical parameters. The method is flexible with respect to wafer formats and materials (excellently suitable for thin wafers too) and is characterized by good automation possibilities, low operating costs and a high system availability.

With the new SiNA®-Generation Roth & Rau offers a modular system for lower cost of ownership, smaller system footprint, reduced power consumptions and new leading edge technologies (e.g. Al2O3).

CAMiNI – Thermal process system

The CAMiNI is, first of all, characterized by high efficiency at low operating costs. The initially offered model with 2 lanes (6” wafers) provides the basis for an extension, which facilitates the firing of solar cell contacts onto up to three lanes at the same time. The throughput of the CAMiNI is indicated with ≥ 6,000 wafers/h.

The Uptime for the new CAMiNI is expected to be 94% and higher. The temperature uniformity is measured by TC and is ± 2K.

An eye-catching development are the transport rolls, which are, in comparison to former machines, made of ceramics and therewith prevent metallic contamination off the wafers. Furthermore, the firing furnace, which needs less space than comparable earlier systems, facilitates an easier handling at lower operating costs.

The CAMiNI firing furnace does not require water cooling and the power consumption of a typical firing process is about 15kW.