What are quartz crucibles used for
Except industrial use for powder etc calcination, quartz crucible are widely used as container for single crystal growth, mainly for silicon single crystal growth by CZ method (Czochralski).
As known, CZ silicon is the most popular material for semiconductor devices and Mono solar panels.
High purity polycrystalline silicon, also called as Poly-silicon, are melted at a temperature of about 1500 ℃ in the quartz crucible container, and then the ingot is pulled from the silicon melt. The ingot pulled is then sliced into wafers for semiconductor or solar use.
Quartz crucible as far is the most suitable container to keep molten silicon at high purity level at the manufacturing process of single crystal silicon, mostly due to its high purity and high temperature resistance.
Quartz crucible production method
The quartz crucibles are produced from quartz powder which is heated and fused with arc heat in the rotating mold.Then the blank quartz crucible is sandblasted (or other method) to remove unmelted powders of outer surface, and cut height as customer request. Finally the crucible is ultimately cleaned and packaged.
Exterior appearances, dimensions, contaminants on inner surfaces of quartz crucibles are inspected before deliverd to customer.
Our crucibles are mainly manufactured with two layer structure comprised of an inner transparent layer with nearly no bubbles and an outer translucent layer with many small bubbles. The inner transparent layer which is in direct contact with the silicon melt and can influence lots of the pulling process and the quality of the pulled ingot. The outer translucent layer is mainly for scattering light from the heater and supply a stable environments for the pulling process.
Also, the purity of the inner layer could be improved by customer request. Now an inner layer with exceptional purity using synthetic silica powder is most popular for high quality semiconductor use.
Many types of quartz crucibles are now in production for different customer request at our factory. More will be supplied with our continued cooperation with our customers.