Hydrogen peroxide (H₂O₂) is a critical chemical in the semiconductor industry, known for its powerful oxidizing properties and its role in ensuring the cleanliness and precision required in manufacturing processes. However, the widespread use of H₂O₂ also creates challenges when it comes to wastewater management. Proper disposal is essential, both for compliance with environmental regulations and for the safety of workers and the surrounding community.

In this blog, we’ll explore how H₂O₂ enters wastewater in the semiconductor industry, common methods of disposal, and how ElectraMet’s innovative Gamma system offers a safer, more efficient, and sustainable solution.

How Hydrogen Peroxide Enters Wastewater in Semiconductor Manufacturing

Hydrogen peroxide is extensively used in semiconductor fabs for various cleaning and etching processes, including:

1. Wafer Cleaning with RCA Solutions:

   • H₂O₂ is a key component of the RCA clean process, which involves removing organic and metallic contaminants from silicon wafers.
   • In the Standard Clean 1 (SC1) stage, H₂O₂ is mixed with ammonium hydroxide and water to oxidize and lift particles.
   • During the Standard Clean 2 (SC2) stage, it is combined with hydrochloric acid to remove metallic residues.

2. Piranha Acid Etching:

   • Piranha acid, a mixture of H₂O₂ and sulfuric acid, is widely used to strip organic contaminants from wafer surfaces. This highly reactive solution generates significant volumes of wastewater containing residual H₂O₂.

3. Surface Treatment and CMP Processes:

   • Hydrogen peroxide is used as an oxidizer in chemical mechanical planarization (CMP) to prepare wafers for the next steps in production, contributing to wastewater streams.

These processes result in wastewater streams containing high concentrations of H₂O₂, which, due to its reactive nature, cannot simply be left in settling tanks to degrade naturally. Without proper management, these streams pose risks to equipment, the environment, and human safety.

Common Methods for Disposing of Hydrogen Peroxide in Wastewater

1. Chemical Neutralization:

   • H₂O₂ is commonly treated with reducing agents like sodium bisulfite, which neutralize it by breaking it down into water and oxygen.
   • While effective, this method generates chemical by-products that require further treatment, adding complexity and cost.
   • The mass of chemicals added to complete the reaction will be proportional to the mass of H2O2. This may make treatment of high concentrations of H2O2 impractical and add considerably to the TDS of the wastewater which is also regulated. 

2. Dilution:

   • Some facilities attempt to dilute H₂O₂ to safe concentrations before discharge.
   • However, this is often impractical in the semiconductor industry due to the high volumes and stringent discharge regulations.
   • While mixing various streams to cause dilution is typically allowed, intentionally adding fresh water for dilution is typically against regulations. 

3. Offsite Hauling:

   • In some cases, wastewater containing H₂O₂ is collected in totes or tanks and transported to offsite facilities for treatment or disposal.
   • This method introduces additional costs and safety risks, including potential spills, leaks, or reactions during transport. The hazards associated with hauling reactive chemicals highlight the need for safer onsite alternatives.

4. Settling Tanks:

   • Allowing H₂O₂ to naturally degrade in settling tanks is an option for low concentrations, but semiconductor fabs often deal with volumes and concentrations too high for this method to be effective.

The Risks of Improper Disposal

Improper disposal of H₂O₂ wastewater poses significant dangers:

• Environmental Damage: If discharged untreated, H₂O₂ can harm aquatic ecosystems as its oxidizing properties cause cell damage to bacteria, plankton, invertebrates, and fish.
• Safety Hazards: The reactive nature of H₂O₂ increases the risk of explosions or chemical reactions during storage, transport, or disposal.
• Disruption of Sewer Treatment Plants: Excessive H2O2 arriving at sewer treatment plants can have a negative impact on the microbial life used to consume and break down organic waste.
• Regulatory Penalties: Non-compliance with environmental regulations can result in fines, operational delays, and damage to a facility’s reputation.

These challenges make it clear that semiconductor manufacturers need advanced, reliable solutions for H₂O₂ management.

How ElectraMet’s Gamma System is Changing the Game

ElectraMet offers an innovative solution to the challenges of hydrogen peroxide disposal. Our Gamma system is designed to treat H₂O₂ and other oxidants directly at the source, providing semiconductor fabs with a safer, more efficient alternative to traditional methods.

Key Advantages of the Gamma System:

1. Onsite Treatment:

   • The Gamma system eliminates the need for offsite hauling, reducing costs and removing the risks associated with transportation and storage of hazardous waste.

2. Chemical-Free Process:

   • Unlike traditional neutralization methods, the Gamma system uses advanced electrochemical technology to break down H₂O₂ into harmless water and oxygen without adding chemicals to the process.

3. Efficiency and Scalability:

   • The system is designed to handle high volumes of wastewater, making it ideal for semiconductor fabs with significant H₂O₂ usage.
   • Its modular design allows it to scale with your facility’s needs, ensuring long-term viability.

4. Automation and Monitoring:

   • Equipped with real-time monitoring and process alerts, the Gamma system ensures consistent performance with minimal manual intervention.
   • This hands-off approach allows facility teams to focus on other critical tasks.

5. Regulatory Compliance:

   • By breaking down H₂O₂ onsite and ensuring safe discharge, the Gamma system helps fabs meet strict environmental regulations while minimizing their environmental footprint.

A Safer, More Sustainable Future

Managing hydrogen peroxide in wastewater is one of the many challenges facing semiconductor manufacturers as they strive for greater sustainability. Traditional methods like hauling and chemical neutralization come with significant risks, costs, and inefficiencies, but ElectraMet’s Gamma system offers a transformative alternative.

By treating H₂O₂ directly onsite, the Gamma system not only reduces costs and safety risks but also supports your facility’s sustainability goals by minimizing chemical use and waste generation. In a highly competitive and environmentally conscious market, this innovation is helping semiconductor fabs set a new standard for safety, efficiency, and environmental responsibility.

Are you ready to explore how ElectraMet can revolutionize your hydrogen peroxide treatment? Contact us today to learn more about the Gamma system and how it can transform your wastewater management.