New very-low-pressure system for Bernex CVD machines

In chemical vapour deposition (CVD) coating, the operating pressure can have a tremendous impact on the resulting coating, both in the quality of the coating and in its properties. For this reason, Bernex is always looking to develop even better pumping systems to extend the process operation window. Now, their new very-low-pressure system (VLPS) is available: VLPS Generation 3 with the brand name Bernex SB3. The module is available both for new Bernex CVD machines and as an upgrade for many machines in the field.

Excellent performance, simpler design

The Bernex very-low-pressure systems are designed for CVD machines needing to operate at pressures below 10mbar. The first generation met that requirement. The second generation was much more technically complex and managed to reach even lower pressures, of 2-3mbar. The latest Bernex SB3 product matches and even exceeds the performance standards set by the previous solutions, with a much simpler and more energy-efficient design.

In the Bernex SB3, the complexity of the module has been reduced, and the pumping capacity increased. The new concept includes a high-capacity dry vacuum pump – a brand-new screw pump type – and fewer pumping stages. In addition, corrosion resistance of the Bernex SB3 has been improved and the cost of ownership dramatically reduced. Because the new design makes the Bernex SB3 a compact, mobile solution, ease of upgrading is increased.

Improved productivity and reliability

The focus of the new Bernex SB3, on top of the low pressures it generates, was on optimising efficiency and capacity. The design of this pumping system – its pump types and system concept – increases the efficiency for multiple factors. The integrated pressure regulation keeps process conditions more stable. The results speak for themselves: for every level of H2 flow, the Bernex SB3 can maintain a lower operating pressure.

Comparison of reactor pressure

Comparison of reactor pressure that can be maintained at different levels as a function of the hydrogen flow.

The Bernex SB3 module was designed to be reliable and low maintenance. The addition of a water cooling system to avoid pump overheating allows more robust operation at a much wider range of process conditions. This ensures process stability even over longer times. The integration of the screw pump design makes the Bernex SB3 module a highly robust product that is not susceptible to blockage. This is important for use with a CVD machine, which operates with high levels of gas and chemicals (H2 and by-products from the CVD process). The new design also allows a much more efficient way of cleaning after a CVD batch. And when maintenance is needed, the mobile design is easy to open and access.

Improved TiAlN coating quality

The new Bernex SB3 not only supports productivity and efficiency; its robustness and the stability of long-term pressure control also results in a higher quality of certain important coatings, such as titanium aluminium nitride (TiAlN). For CVD-deposited TiAlN, it is important that the deposition conditions are controlled very precisely, especially the residence time of the reactants. Bernex SB3 allows our customers to reduce the residence time of the reactants by a highly controlled increase of the gas flow and reduction of the process pressure at the same time.

This is of great benefit to the coating’s homogeneity. Small deviations in the coating process window cause the coating to have different properties, thus impacting the resulting coating quality. This new module has the required stable operation and long-term pressure control to create uninterrupted optimal process conditions. And because its design avoids any chemicals blockages, it increases productivity while reducing production costs at the same time.

Are you interested in learning more about the new Bernex SB3 or about upgrading your current Bernex systems? Please contact Philippe Ricklin (+41 79 330 29 59 or