7N Grade Synthetic Quartz Sand Has Entered Mass Production!

For a long time, my country's semiconductor industry chain has been heavily reliant on imports for 7N-grade high-purity quartz sand, used in advanced semiconductor manufacturing processes. This has been a key bottleneck in the industry chain. As chip technology continues to evolve, advanced processes have placed extremely stringent demands on the purity, uniformity, and stability of the quartz substrate.

Recently, a Chinese quartz factory has achieved a significant technological leap from natural quartz ore purification to high-purity chemical synthesis. They have established a comprehensive technology chain encompassing precursor technology, chemical synthesis processes, core equipment development, and application verification. They have successfully developed and mass-produced 7N-grade (99.99999%) synthetic quartz sand with a total specific impurity content of less than 20 ppb, with fully independent intellectual property rights. This synthetic sand is used in the production of semiconductor-grade quartz crucibles, photolithography, and etching processes, among other key processes.

This success is no accident. The company has steadily accumulated experience in high-purity quartz synthesis, developed a variety of advanced technologies for process control, and prioritized detailed optimization, such as raw material purity control, residual material removal, particle size control, dispersion technology, and doping processes. These technologies have been transformed into competitive patents.

Process for Synthesizing High-Purity Quartz Sand from Silicon Tetrachloride by Liquid-Phase Hydrolysis

This invention discloses a process for synthesizing high-purity quartz sand from silicon tetrachloride by liquid-phase hydrolysis. The process involves liquid-phase hydrolysis of silicon tetrachloride with water. The product undergoes washing, solid-liquid separation, drying, calcination, grinding, and screening to obtain high-purity quartz powder. A heating step is included during solid-liquid separation, between washing and solid-liquid separation, or during washing to promote the decomposition of orthosilicic acid into metasilicic acid, facilitate transfer and cleaning, and reduce raw material waste. The drying temperature is 100-200°C, and the calcination temperature is 1300-1500°C. The calcination furnace design is optimized to ensure uniform heating and prevent powder agglomeration.

Process for Preparing Ultra-High-Purity Amorphous Silica Synthesized Quartz Sand

This invention discloses a process for preparing ultra-high-purity amorphous silica synthesized quartz sand. The process involves the high-temperature and high-pressure reaction of amorphous silica, a mineralizer, and ultrapure water, followed by solid-liquid separation during discharge. The product is then ground, acid-washed, cleaned, and dried to obtain the product. This process utilizes reactor pressure to achieve solid-liquid separation during unloading, saving costs. It also utilizes amorphous silica, boasting high and controllable purity, alleviating the shortage of high-quality quartz ore in my country. The resulting quartz sand has a low aluminum content and a low total amount of nine impurities.

A Semiconductor-Grade Synthetic Quartz Preparation Process

This semiconductor-grade synthetic quartz preparation process includes four steps: material preparation, impurity removal, ion exchange, and aging purification. Material preparation involves adding alkali metal silicate to the equipment and dissolving and diluting it with medium-temperature pure water. Impurity removal involves adding an impurity remover, stirring, allowing the mixture to settle, and filtering to separate heavy metal hydroxides and the solution to be exchanged. Ion exchange involves passing the solution to be exchanged through a strong-acid cation exchange column to remove calcium and sodium ions, resulting in a sol. Aging purification involves allowing the sol to stand to produce an initial gel, which is then subjected to aging, washing, drying, pulverization, sintering, and ultra-high-purity purification to obtain the product. This process utilizes integrated equipment to enhance automation and efficiency.