Silicon Valley Microelectronics, Inc. (SVM) products

Growing a silicon ingot can take anywhere from one week to one month, depending on many factors, including size, quality and specifications. More than 75% of all single crystal silicon wafers are grown using the Czochralski (CZ) method. CZ ingot growth requires chunks of virgin polycrystalline silicon. These chunks are placed in a quartz crucible along with small quantities of elements called dopants, the most common of which are boron, phosphorus, aresenic and antimony. The added dopants give the desired electrical properties for the grown ingot and depending on which dopant is used, the ingot becomes a P or N type ingot (Boron: P type; Phosphorus, Antimony, Arsenic: N type).

Tops and Tails are derived from a fully-grown polysilicon ingot.  Once fully grown, an ingot is removed from the quartz crucible from which it was pulled. Because the ingot was pulled at various speeds during growth, the ends are narrower than the silicon body. The narrow sections of the ingot are removed from the cylindrical body. These ends can be re-melted and used again in the growing process.

Ingots are grown through a process known as Czochralski (CZ) method. CZ ingot growth requires chunks of virgin polycrystalline silicon which are placed in a quartz crucible along with small quantities of elements called dopants – the most common of which are boron, phosphorus, arsenic and antimony. The materials are heated to a temperature above the melting point of silicon, 1420 degrees Celsius. Once the polycrystalline and dopant combination has been liquefied, a single silicon crystal, the seed, is positioned on top of the melt, barely touching the surface. The seed has the same crystal orientation required in the finished ingot.