The float-zone process produces high-purity crystals, which serves as a foundation into creating a float zone wafer. The wafers produced through the float-zone process have extremely low levels of light impurities. This helps in restraining micro-defects to improve the mechanical strength of the wafers. A float zone wafer is also considered to be the better alternative compared to wafers grown through the CZ method. This might just be the wafer you need for your next project. Read on to know more about the process of obtaining float zone silicon wafers:
In 1962, Theuerer invented the zone-melting principle, which is the basis for the Float Zone method. The process occurs inside a vacuum or a passive gaseous atmosphere. It starts with a high-purity crystalline rod and monocrystalline seed crystals that are held parallel against each other in a vertical position as it rotates. And as it partially melts with a radio frequency field, the seed is brought up to touch with a drop of melt at the very top of the poly rod. Next, a necking process is done to create a dislocation-free crystal before a taper forms and reaches the set diameter for steady-state growth.
The molten silicon solidifies into a single crystal as the molten zone passes along the polysilicon, which purifies the material. Then, the crystals go through doping which is where gas phosphine or diborane are added. And because the FZ silicon doesn’t come in contact with any other substances aside from ambient gas, it can easily achieve high purity and resistivity. Furthermore; multiple zone refining can be done on a single rod to help further diminish any impurity concentrations.
If you’re looking for a highly efficient wafer that can be used in multiple applications, like discrete power devices, RF chips, high-efficiency solar cells, and optical products, then a float zone wafer is what you need. At Wafer World, we offer high-quality wafers at the best price possible, and excellent customer service. Call us for inquiries or visit our website for more!