Microtechnology has made enormous strides since its beginnings in 1948. Even today, after almost 60 years, Moore’s law stating that the number of transistors on a chip doubles every twelve months (later eighteen months) still applies! The desire for ever greater computing capacity and increasing mobility are the most important driving forces. Several million transistors can now be mounted on a wafer with a typical edge length of a few millimetres, and standard wafers are now 300 mm and provide space for several thousand chips. The heart of the chip industry beats with the most important semiconductor material, silicon, available in immeasurable quantities on this planet in the form of quartz sand (SiO₂).

The key to the efficiency and quality of today’s chips lies in their extraordinarily high purity. Large parts of their production are therefore realised in clean rooms ranging from Class 10 upwards in which a maximum of 10 particles per m³ air may occur. The demands made of the materials used are also high, particularly those that are in immediate contact with the silicon. This entails the almost exclusive use of quartz glass, CFC composite materials and graphite (which are also produced at comparably high purity levels). This applies in particular to production of single silicon crystals. In addition to the materials mentioned, ultra-pure ceramics (in part coated) and metals are also used during further processing of Si wafers.