Float-zone silicon is an alternative to crystals grown by the Czochralski process. With silicon being the most abundant solid element on earth, it’s no surprise that silicon is the most common and popular material used in the making of wafers. Let’s take a look at the float zone method and how it is used to make an FZ wafer.
The float zone method was invented by Henry Theuerer in 1962. Upon its creation, it was based on the zone-melting principle. The process begins with a high-purity polycrystalline rod and a monocrystalline seed crystal. They are held face to face in a vertical position and are rotated. From there, both are then partially melted via radio frequency. A necking process is then carried out to establish a dislocation-free crystal. This is done before the neck is allowed to increase in diameter to form a taper and reach the desired diameter for steady-state growth. As the molten material is moved along, it solidifies and is purified. Unlike CZ growth, the silicon molten zone is not in contact with any substances except ambient gas, which may only contain doping gas. As a result, FZ silicon can easily achieve much higher purity and higher resistivity.
With silicon being so abundant, it’s no wonder that silicon wafers are so popular. If you are in the market for silicon wafers, including FZ wafers, we are the perfect place for you. Contact us today to learn more about our wafers and to place an order.