Polycrystalline Silicon Boron Removal Resin

Polycrystalline silicon is the basic raw material for the preparation of silicon solar cells, various silicon discrete devices, and various silicon integrated circuits. It is a strategic material for the development of the solar energy industry and the information microelectronics industry.

There are two existing methods for purifying industrial polycrystalline silicon from 1N-2N to 6N-7N solar grade polycrystalline silicon and 9N-12N electron grade polycrystalline silicon: physical methods and chemical methods.

Although these methods can remove most metal impurities, the physical method of impurity separation and purification is not suitable for the removal of boron and phosphorus impurities in silicon, because the separation coefficient of boron in silicon is 0.8 and phosphorus is 0.35, both close to 1, and the effect of separation and purification is very poor.

Adsorption method is an operational method that uses solid adsorbents to adsorb and separate impurities in polycrystalline silicon production. The basic principle is based on the differences in the size and polarity of compound molecules for adsorption and separation.

Boron and phosphorus impurities such as BCl3 and PCl3 in polycrystalline silicon production are asymmetric molecules with considerable dipole moments, strong polarity, and a strong tendency to form addition chemical bonds, which are easily adsorbed by adsorbents. The main mechanism of boron adsorption is chelation, and most boron adsorbents mainly utilize the chelation between functional groups and boron to adsorb and remove boron. The main mechanism of phosphorus adsorption is chemical adsorption in the form of coordination complexation and ion exchange.

In summary, the general requirements for adsorbents include: 1) having a large surface area; 2) Two have high surface activity.

Based on this, Haipu has developed multiple types of polycrystalline silicon boron removal resins. Haipu polycrystalline silicon boron removal resin is a multifunctional special resin that not only has functional groups for selectively removing boron and phosphorus impurities, but also has catalytic anti disproportionation reaction groups, which can meet the relevant application needs of the polycrystalline silicon industry.

HPC-118 is suitable for removing boron and phosphorus impurities in polycrystalline silicon, and can also assist in anti disproportionation reactions.