The Lower Bavarian company RW silicon GmbH is the only manufacturer in Germany to produce high-purity silicon, from which wafers for semiconductor chips can be manufactured. However, due to the enormous increase in electricity prices, RW silicon had to temporarily stop production and currently only operates one of four electric arc furnaces. This consequence of high energy costs in Germany highlights hurdles standing in the way of plans to boost semiconductor production within the European Union (EU).
The manufacture of some basic materials for semiconductor production is extremely energy-intensive. The managing director of RW silicium explained to Niederbayern TV from Passau that the production of one ton of silicon from quartz and carbon consumes around 15,000 kilowatt hours of electricity. This amount of energy can heat an older single-family home for a year.
From sand to chip: CMOS semiconductor components are made on wafers made of pure silicon.
(Image: c’t magazine)
RW silicon only produces the silicon as a metal. It is also used for metal alloys and as a base for silicones. Even more energy is needed to clean raw silicon in the melt and grow a huge monocrystal from it, which can be sawn into wafers with a diameter of 20 or 30 centimeters. For example, processing is carried out by the former Wacker division Siltronic, which is based in Burghausen, around 60 kilometers from Pocking am Inn. This is no coincidence, because Wacker operates its own hydroelectric power plants on the Alz, which flows into the Inn, to cover the high energy requirements.
Subsidized industrial electricity price
At the end of March, RW-silicon Managing Director Stefan Bauer had already asked Bavarian Radio for discounted electricity for industry, which is also available in other countries. However, Professor Karen Pittel from the Ifo Institute for Economic Research considers such an industrial electricity price to be “hardly feasible”, as she recently explained in an interview with the taz. Because that “would cost large sums of tax money”. She also assumes that the local energy costs will not be reduced to the much lower level as in the USA.
PCC BakkiSilicon silicon factory in Iceland
(Image: PCC BakkiSilicon)
The high energy costs in Germany also endanger the settlement of other energy-intensive factories, such as the planned Northvolt battery production near Heide in Schleswig-Holstein. Intel is said to be struggling with electricity costs when planning the chip fabs in Magdeburg. In an interview with c’t, Intel CEO Pat Gelsinger in autumn 2022 dismissed the fact that energy costs only make up a relatively small proportion of the total costs of a chip fab. Intel had also emphasized that Saxony-Anhalt already produces enough wind power for a CO2-neutral chip production there.
emigration to low-cost countries
In some European countries like Norway there is a lot of cheap hydroelectric power. Therefore, some companies with a particularly high demand for electrical energy have settled there, such as the aluminum producers Norsk Hydro and Alcoa. Wacker is also planning to expand silicon metal production at its Norwegian site in Holla. In Norway, however, there is already a serious shortage of skilled workers and most of the country is very sparsely populated.
Wacker silicon factory in Norway
(Image: Wacker)
In the EU country Iceland, PCC BakkiSilicon has built a new plant for silicon metal, which at 32,000 tons per year has a slightly higher capacity than RW silicon and uses energy from geothermal power plants. PCC BakkiSilicon says it imports quartz sand from Poland. According to PCC BakkiSilicon, the silicon manufactured there is also suitable for solar cells, which, however, do not require wafer material that is as pure as semiconductor components.
In the EU country Sweden, on the other hand, there are a number of plants that produce silicon carbide (SiC) wafers. Because of the extremely hard material, which is also used as an abrasive, it takes more time and energy to saw up and polish the wafers than with silicon wafers.
RW silicon is a subsidiary of the Dutch registered Advanced Metallurgical Group (AMG NV). In 2012, AMG completely took over the company Graphit Kropfmühl, the owner of the RW silicon. The latter is also known as Rottwerk.
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