The manufacturing workshop of the semiconductor industry is full of crises, especially some invisible toxic gases or wastewater. This article also lists some of their own see and feelings, everyone, together to protect themselves, protect the environment.
Just say a photolithography process, photoresist containing components are toxic, but the difference between the levels of toxicity. HMDS can be carcinogenic substances, if not necessary, it is recommended that you try not to touch them. The use of HMDS also requires the purchase of professional automation equipment, containment, and vacuum extraction equipment.
For photoresists, developers must be recycled, and turn in a professional company to do hazardous waste recycling. There are even companies that can’t even discharge wastewater directly into the sewer pipe, requiring a third party to pull it away.
The semiconductor production process includes a cleaning process, coating process, ion injection process, photolithography, corrosion etching, metallization, and other processes.
In fact, a large amount of wastewater produced by the semiconductor industry, if not treated in time, will not only destroy the social-ecological environment but also directly threaten the health and safety of human life. If the fluorine-containing wastewater in the semiconductor industry is discharged directly, it is not carefully ingested by plants, animals, or even slowly into the human body, it will harm human health and cause a series of diseases. If the ammonium-containing wastewater is discharged directly, the most obvious manifestation is the multiplication of a large number of algae, which causes the water body to begin to form serious eutrophication and even produce nitrosamines with serious carcinogenicity. If the copper-containing wastewater is directly discharged into the environment, it will directly damage the water quality, and a large amount of copper intake by the human body will lead to serious liver disease.
Treatment technology of wastewater containing fluorine
Fluorine-containing wastewater treatment process Fluorine-containing wastewater treatment process fluorine-containing wastewater is mainly produced by the etching process during chip production, which requires hydrofluoric acid and ammonium fluoride, and other substances. For the effective treatment of fluorine-containing wastewater, enterprises generally choose the chemical precipitation method, ion exchange method, and other methods. For example, the chemical precipitation method is adopted for fluorine-containing wastewater with a fluoride concentration of 747mg/L, and the pH value of wastewater is adjusted to about 7.5. Calcium chloride solution, PAM, PAC, and other substances are added to the wastewater. The concentration of fluoride in water is reduced to 40mg/L. It can be seen that the coagulation and precipitation treatment method can effectively treat the wastewater containing fluorine concentration of about 500mg/L, and the removal rate can reach more than 90%.
CMP wastewater treatment process
CMP wastewater treatment process Chemical mechanical grinding is used during chip production in semiconductor plants. Abrasive is a mixture of abrasive and corrosive ingredients. After grinding, the surface of the silicon wafer needs to be washed with pure water to ensure that there is no residual abrasive fluid on the surface. CMP wastewater contains suspended particles with a particle size above 70nm, metal oxides, and different chemical reagents. The concentration of suspended particles in water is relatively high, and the stability is strong, so it is difficult to effectively remove them. It is suggested to divide CMP wastewater into oxidized layer and metal layer grinding wastewater in detail according to the actual type of grinding surface, and then treat and recycle the wastewater by electrochemistry or coagulation.
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