What high-purity quartz products are used in integrated circuit processes? What are the requirements for impurity content?

High-purity quartz products commonly used in integrated circuit processes include quartz wafers, quartz crystals, quartz tubes, and quartz windows.

For quartz wafers, the impurity content must be extremely low, generally in the parts per billion (ppb) or lower range. This is because the wafers are subjected to high temperatures, pressures, strong acids, strong bases, and other conditions during the manufacturing process, and impurities can affect the electrical properties and reliability of the wafers.

For quartz crystals, the impurity content must also be kept as low as possible, typically in the ppb range. Quartz crystals are used to make components such as oscillators and filters, and impurities can affect their frequency stability and performance.

For quartz tubes and quartz windows, the impurity content must be relatively low, generally in the parts per million (ppm) range. Quartz tubes and windows are used to make vacuum equipment and optical devices, and impurities can affect their physical and optical properties.

In summary, the impurity content requirements for high-purity quartz products used in integrated circuit processes are very strict, and impurities must be minimized to reduce their impact on device performance.