In the early 1990s, Topsil engineers decide to aim for simplifying the manufacture of silicon. They believe that zone purification by use of float zone technology - which constitutes the last part of the ready-making process before melting the raw material, might no longer be necessary to obtain a satisfactory end result.
Topsil starts utilising the float zone technology as its silicon manufacturing methodology and launches a new type of silicon, that is the gas phase doped "preferred float zone" (PFZ) silicon product targeting medium voltage components. The product is developed out of earlier product generations back to the early 1970s.
Late in the 1990s, the wafer diameters once again become bigger, up to 150mm, driven by customer requirements. Concurrently, Topsil begins to develop float zone based PV silicon for solar cell panels. The solar industry is on its rise and Topsil identifies an opportunity to develop ultra-pure silicon for high efficiency solar cells.
After some time on the market, however, stretching into the new millenium and involving various kinds of owners and financing, stretching into the new millennium, Topsil draws the conclusion that although float zone based PV silicon indeed is more efficient than other types of silicon available for solar cells, a profitable mass production has not been obtained. Consequently, the manufacture of PV silicon becomes scaled down.