CZ silicon is the most used material in semiconductor manufacturing due to its widespread availability and low cost. However, an FZ wafer, capable of offering ultra-high purity, minimal oxygen concentration, or low resistivity variation, among other factors, may be a better choice for specific applications.
However, sometimes the rare materials used in semiconductors spark concerns about public safety. While float zones are generally safe to handle, here we’ll explore in which situation they can be toxic for humans.
No, the float zone method does not produce toxic wafers. Solid silicon wafers are chemically stable and a naturally occurring element.
It’s not reactive, which means it doesn’t react with skin or air under normal conditions. Furthermore, handling silicon wafers with bare hands is not dangerous. In cleanroom environments, gloves are advised to avoid contaminating the wafer, not to protect you.
Although FZ silicon is usually safe, cutting, grounding, or polishing it can make it dangerous. Since silicon dust irritates the respiratory system, breathing in the dust created during these procedures may be dangerous.
Chronic inhalation of fine crystalline silica (if present) can lead to silicosis, a serious lung condition.
Furthermore, chemical byproducts from processing wafers with strong acids, dopants, or etching chemicals may be dangerous; however, this is more related to the processing environment than the wafer itself.
Certain wafers are purposefully doped with phosphorus or arsenic. In normal use, dopants are not hazardous due to their low concentrations and internal crystal structure trapping. Nevertheless, those dopants may turn toxic in gas or liquid form if the wafer dissolves or vaporizes—again, only pertinent in industrial settings.
When used or handled properly, FZ wafers are not toxic. Toxicity risks only arise during manufacturing, processing, or improper disposal, especially involving wafer dust or chemical etching. However, companies like Wafer World take the proper measures to ensure the health of workers and engineers working with these materials.
The problem lies in students and scientists handling FZ wafers in a non-industrial setting, often for educational or electronic prototyping purposes, without proper care. If you’d like to learn more about safety guidelines for your project, contact us today!
