Enhancing sustainability RCA Clean Processes with Advanced Metal Recovery Solutions

In semiconductor manufacturing, cleanliness is critical to ensuring the efficiency and performance of delicate silicon wafers. One of the most essential cleaning methods is the RCA Clean process, developed to remove organic, inorganic, and metallic contaminants from wafer surfaces. This process is integral in the production of high-performance electronics, where even the smallest impurities can lead to defects in the final product. Sulfuric peroxide mixes, including piranha acid, are used in various applications to remove organics and prepare surfaces for the next stage in processing.

At ElectraMet, we specialize in innovative water treatment solutions using electrochemistry and catalysis to eliminate peroxide from strong acids and bases, enabling chemistry recovery and recycling. .

Let’s explore the RCA Clean process, its importance, and how ElectraMet’s technologies enhance sustainability and efficiency in semiconductor manufacturing.

What is the RCA Clean Process?

The RCA Clean process, developed in the 1960s, is used to clean silicon wafers before high-precision manufacturing steps. This multi-step cleaning protocol includes several key chemical baths designed to remove different types of contaminants from wafer surfaces:

Organic Clean (Standard Clean 1 – SC1): A mixture of ammonium hydroxide (NH₄OH), hydrogen peroxide (H₂O₂), and deionized water is used to remove organic contaminants, particles, and some metals. This solution is typically referred to as APM, or ammonia peroxide mixture.

Metallic Clean (Standard Clean 2 – SC2): A solution of hydrochloric acid (HCl), hydrogen peroxide (H₂O₂), and deionized water removes any remaining metallic contaminants.

Oxide Removal: A quick dip in hydrofluoric acid (HF) removes the native oxide layer from the wafer surface.

While RCA Clean is highly effective, it produces wastewater streams rich in peroxide and other hazardous chemicals.

Sulfuric Peroxide Mixes (SPMs) are also used across many segments of semiconductor fabrication. Like RCA Cleaning, the goals are similar, in that the chemistry is used to clean and/or etch the surfaces for preparation of the next fabrication step.

Until now, there was no economically viable solution for complete abatement of peroxide from SC-1 (APMs) and no effective solution for SPMs without generating significant byproducts and jeopardizing downstream processes and assets. ElectraMet’s Gamma System was created to help manufacturers complete zero-waste initiatives and enable complete recycling of sulfuric acid, turning a wasteful process into a circular process. .

The Economic Importance of Peroxide Treatment in Semiconductor Manufacturing

Peroxide treatment is crucial for semiconductor manufacturers due to its impact on both operational and cost efficiencies. Excess peroxide in APM and SPM waste streams can increase treatment expenses, risk equipment degradation, and disrupt chemical recovery processes. Efficient abatement ensures cost-effective operation and reduces the need for fresh chemical inputs by allowing facilities to recycle valuable chemicals.

ElectraMet’s advanced systems offer significant cost-saving benefits by capturing and removing peroxide from these streams. The advantages of peroxide treatment include:

• Reduced Chemical Purchases: By reclaiming sulfuric acid and ammonia from treated waste streams, facilities cut down on raw chemical expenses.
• Minimized Maintenance Costs: Effective peroxide abatement protects downstream equipment from oxidative wear, extending system longevity and reducing maintenance needs.
• Lower Waste Disposal Costs: With peroxide removed, waste streams become less hazardous, reducing disposal costs.

Semiconductor facilities require efficient solutions to address these challenges while maintaining operational efficiency. That’s where ElectraMet’s technology makes a significant difference.

How ElectraMet Optimizes the SPM, APM, and Peroxide Abatement Process:

ElectraMet’s advanced peroxide abatement and resource reclamation systems help semiconductor facilities treat peroxide-rich wastewater effectively without introducing detrimental byproducts. By focusing on peroxide abatement, our systems create opportunities for cost savings, new revenue streams, and compliance assurance.

Key Benefits of ElectraMet Systems:

• Efficient Peroxide Abatement: ElectraMet’s systems effectively remove peroxide from wastewater streams generated in semiconductor fabrication without introducing new contaminants.
• Regulatory Compliance: By removing harmful analytes from wastewater, ElectraMet ensures that semiconductor facilities meet strict environmental regulations, reducing the risk of fines or operational shutdowns.
• Sustainability: ElectraMet’s systems contribute to sustainable manufacturing practices by reducing hazardous waste and enabling facilities to achieve zero-liquid discharge (ZLD) or zero-waste goals, minimizing the environmental footprint of the semiconductor industry.
• Monetization of Previous Waste Products: By eliminating the peroxide without generating detrimental byproducts, sulfuric acid and ammonia can be reclaimed, reused, or sold. After peroxide removal, these streams consist of purified acid or base and ultrapure water. If desired, these streams can be purified and sold as microelectronics grade materials.

Conclusion: Deliver Peroxide Remediation with ElectraMet’s Peroxide Removal Solutions

As semiconductor manufacturing continues to evolve, ensuring the cleanliness of silicon wafers remains critical for maintaining product quality. Managing the peroxide introduced in this process presents ongoing challenges that can translate into cost-saving opportunities.

ElectraMet’s advanced, best-in-class technology is the ideal solution for semiconductor waste management, offering innovative, efficient, and sustainable approaches. By integrating ElectraMet’s systems into your wastewater treatment process, you not only protect the environment but also gain compliance assurance and reduce operational costs.

Interested in learning more? Contact ElectraMet today to see how our systems can enhance your fabrication process while driving sustainability and profitability in your facility.