Fused Quartz Crucibles

Semicorex Fused Quartz Crucibles are valuable consumables used in semiconductor manufacturing, with significant purity, thermal stability and mechanical strength in extreme temperature environments. These crucibles are manufactured from high purity silica sand that is fused together using a highly controlled melting technique to achieve the highest available density, with a mostly homogeneous material with limited inclusions or bubbles in its structure that is very reproducible for crystal pull-back and wafer productions. These crucibles have ultra-low levels of contamination making them ideal for processes where material purity directly affects the yield and performance of the device.

Fused quartz crucibles are used in semiconductor production for the Czochralski (CZ) method of single crystal silicon growth. Fused quartz crucibles have high thermal resistance allowing them to withstand temperatures to melt polysilicon that are often higher than 1400°C.  Additionally fused quartz crucibles are chemically inert and will not react with the polysilicon in a manner that would affect the purity of the silicon.  Fused quartz crucibles can undergo very substantial thermal cycling without a loss of structural integrity and this can provide a steady state condition for the growth of the seed into a crystal structure, thus achieving necessary uniformity in semiconductor wafers.

The fused quartz's optical properties and mechanical characteristics yield unique advantages in a semiconductor setting. The low coefficient of thermal expansion will mitigate thermal shock and dimensional inconsistency while the low thermal conductance will aid in preserving temperature gradients in the crystal growth furnace relative to the crystal. The inner surface of the crucible being smooth past thermal will minimize particulate generation and will promote uniform melt behavior which will further protect the purity of the grown crystal.

The manufacturing processes employed to ensure each fused quartz crucible conform is consist with stringent dimensional tolerances and surface qualities. The selection of raw materials is screened to eliminate metallic contaminants, melting takes place in a specialized environment that negates atmospheric gas and/or particulate contamination. Based on the semiconductor application, crucibles can be made in several diameters and wall thicknesses, from small research crucibles, to large diameter crucibles capable of producing 300 mm wafers.

While the unique properties of a fused quartz crucible already improve durability and performance, additional specialized surface treatments or coatings can be employed when needed. For example, some processes will involve inner silicon layer deposits to improve the crucible's life span or to further minimize the amount of oxygen getting to the molten silicon. These improvements help the efficiency of semiconductor production if the process uses a quartz crucible, because it reduces the frequency of replacement and results in greater yields of crystals.

Fused quartz crucibles also have a role in research and development of new processes in the semiconductor industry. Its adaptability gives engineers the ability to explore alternate crystal growing techniques, materials doping technologies, or new semiconductor materials outside of silicon, like gallium arsenide or silicon carbide. The fused quartz crucible's ability to withstand extreme chemical and thermal conditions gives engineers the ultimate assurance in both mass production and experimental fabrication.

Semicorex fused quartz crucibles have become critical tools in today's semiconductor manufacturing, featuring high purity, superior thermal properties, and incredible structural stability in regard to the strictest industry standards. Thus, their ability to generate defect free, and high-performance semiconductor wafers directly influence the reliability and performance of electronic devices across the globe.