How to Develop a Requirements List When Buying Wet Bench Equipment

How to Develop a Requirements List When Buying Wet Bench EquipmentEditor’s Note: This article was originally published in March 2015 and has been updated with new information and reposted in August 2023.

Wet bench equipment is an integral component that semiconductor manufacturing and research industries need. From cleaning, etching, stripping, developing, and testing new processes, it plays a vital role in these fields. The range of wet bench systems and equipment include manual, semi-automated, and fully automated, offering various operator control levels and process automation. The versatility provided by these systems ensures they can handle many manufacturing processes to meet the demands of both Process Engineers and R&D professionals.

Before investing in wet bench equipment, creating a comprehensive requirements list is essential. Outlining your exact process requirements is an important strategic step that will guide you in selecting an optimal, efficient, cost-effective system that meets them perfectly. This article provides insights into understanding wet bench equipment requirements to facilitate an easier selection process tailored to the specific needs of Process Engineers and R&D professionals.

Understanding Wet Bench Requirements

Selecting Wet Bench Equipment for Specific Processes

Semiconductor manufacturing entails many steps, each requiring specialized equipment. The processes can range from acid-based to solvent-based, each with distinct challenges and requirements. For instance, while acid-based processes may require corrosion-resistant equipment, solvent-based processes require stainless-steel equipment with specialized venting or safety systems.

The Importance of Affordable and Dependable Equipment with an Extended Service Plan

Investment in wet bench equipment should be seen as a long-term commitment, not a one-time purchase transaction. Therefore, its long-term reliability should be given equal weight to its initial price tag. Equipment with consistent performance over time offers better returns by lowering the total cost of ownership. Investing in comprehensive service plans such as those provided by Modutek can also significantly decrease maintenance-related concerns. These plans ensure your equipment receives regular maintenance and support, enhancing its operational lifespan and reducing potential downtime.

The Need for Consistent and Repeatable Processes

Efficiency in semiconductor manufacturing relies heavily on consistent, repeatable processes. Therefore, wet bench systems must be user-friendly and designed to deliver repeatable processes, ensuring consistent output. Equipment that allows for easy process adjustments that provide consistent results can significantly improve the productivity and efficiency of your manufacturing operations.

Precise Process Control and Safety Measures

In semiconductor manufacturing, precision and safety are of utmost importance. Wet bench equipment should incorporate precise process controls that ensure accurate and reliable results. In addition, stringent safety measures such as exhaust/chemical fume hood filtration or CO2 fire suppression systems are critical. These features protect operators and provide safeguards against potential hazards, making working conditions safer to promote greater productivity.

Cleanliness and Chemical Compatibility in Wet Bench Stations

Semiconductor manufacturing requires stringent cleanliness standards and specific chemical compatibilities.  Wet bench systems must maintain a contaminant-free environment, ensuring the quality and reliability of the semiconductor products.  In addition, the equipment should be compatible with the range of chemicals used in your specific manufacturing process. This contributes towards better operational efficiency as well as longevity of equipment used.

Consistent and Trackable Data from Wet Bench, Chemical Delivery, and Chemical Treatment Systems

Data-driven decision-making is critical in semiconductor manufacturing. Therefore, your wet bench, chemical delivery, and chemical treatment systems must provide consistent, trackable data. This data allows for efficient process control and quality assurance, which can provide valuable insights for process improvement. This real-time monitoring and data-tracking capability can significantly enhance overall efficiency and effectiveness.

Wafer and Substrate Size Requirements

Whether your operations involve processing small batches of wafers or engaging in large-scale manufacturing, it’s crucial to have equipment capable of handling your specific wafer and substrate sizes. Modutek’s wet bench stations can handle all manufacturing processes and wafer sizes up to 12 inches. Whether you choose a manual, automated, or semi-automated system, this flexibility ensures that your manufacturing operations are not limited by the size of your substrates or wafers.

Wafer Volume Requirements Per Day/Week

Your production scale and wafer volume requirements play a crucial role in selecting the appropriate equipment. Automated wet bench systems offer maximum throughput, while semi-automated systems offer lower throughput with some manual operator interaction. A manual wet processing bench provides the most cost-effective solution for small-scale, low-volume operations.

Cassettes per Bath and Wafer Transfer Requirements

Different wet bench systems feature varying capacities for accommodating cassettes per bath. Your specific requirements and desired automation level when transferring wafers between baths should determine your equipment selection. Manual or automated transfer can have significant ramifications on process efficiency as well as the risk of contamination.

Compliance With Recognized Standards

Compliance with industry standards such as FM Global Standards is paramount when purchasing manufacturing equipment. If this approval assessment process is required in your operations, you should ensure that your selected wet bench system meets these standards for a compliance-centric and confident approach to purchasing.

Third-Party Electrical Inspection

The consistency and efficiency of the system can be evaluated with tests like SEMI S2, CE, or third-party inspections.  Modutek adheres to guidelines such as SEMI S2, NFPA, and NEC for manufacturing wet process equipment.  They also provide quotes for inspection reports as requested, ensuring the system meets the necessary standards and performs optimally.

Maintenance, Service, and Delivery Requirements

Establishing precise requirements regarding maintenance, service, and delivery is vital.  Factors to consider include equipment delivery times, installation support, operator training sessions, regular maintenance schedules, and service response times in case of equipment failure. A comprehensive understanding of these aspects ensures smooth operations while swiftly resolving potential issues, minimizing downtime, and maintaining productivity.

Selecting Wet Bench Equipment that Best Suits Your Processing Needs

Key Considerations in Selecting Manual, Semi-Automated, or Fully Automated Wet Bench Systems

Selecting the appropriate wet bench system depends heavily upon your specific chemical processing and throughput needs. Manual wet processing stations are more suitable for new complex processes requiring close operator control, such as R&D operations or prototype development.  On the other hand,  automated and semi-automated systems are ideal for operations requiring higher throughput with minimal operator involvement. These aspects will help you select a system matching your requirements to maximize productivity and efficiency.

The Importance of Precise Control Over Temperature, Agitation, and Chemical Delivery

Temperature, agitation, and chemical delivery all play an essential part in semiconductor manufacturing processes. Therefore, your wet bench equipment must provide precise control over these factors to guarantee accurate, consistent results that improve both product quality and operational efficiency. Systems offering this level of control will deliver accurate and repeatable results to improve both your products and operational efficiencies overall.

The Need for Flexible, Customizable, and Reliable Systems and Equipment Compatibility

As semiconductor manufacturing continues to advance rapidly, its ever-evolving processes necessitate flexible and adaptable systems. Your wet bench equipment should adapt easily to changes in your processes, ensuring long-term applicability and return on investment. Furthermore, the equipment should be compatible with other lab or manufacturing equipment, allowing seamless integration into your current setup. This helps prevent operational issues and streamlines maintenance and repair processes.

The Importance of Supplier Credibility and Expertise

Selecting an equipment supplier is a critical aspect of purchasing wet bench equipment. Reputable suppliers with extensive expertise can deliver reliable systems that meet your exact specifications while providing valuable advice and assistance so you can make informed decisions. Conducting thorough research and engaging with companies like Modutek will ensure you find a reliable partner for your equipment needs.

The Importance of Experience and Guarantees

Experience and longevity is a strong indicator of a supplier’s ability to provide high-quality equipment and services. Suppliers with experience typically have a proven track record of meeting customer requirements and overcoming complex operational challenges. Furthermore, supplier guarantees can provide added assurance regarding system reliability and performance. Look for suppliers offering warranties on their products, ensuring they stand by their equipment.

The Value of Proven Track Records and Innovative Solutions

A proven track record can be a reliable indicator of a supplier’s ability to meet your requirements consistently. Suppliers with a history of delivering high-quality, reliable equipment along with innovative solutions are likely to continue doing so in the future. Innovative solutions also demonstrate their dedication to staying abreast of industry changes while meeting changing customer demands.

The Necessity for Flexible, Customizable, and Reliable Systems

As previously discussed, flexible, customizable, and reliable systems are crucial in semiconductor manufacturing’s ever-evolving environment. Your wet bench equipment should adapt easily to process changes while remaining applicable and useful over time. Customizable solutions also offer additional benefits by being explicitly tailored to your process requirements – potentially improving operational efficiency and effectiveness simultaneously.

The Importance of Cost Considerations in a Budget

While investing in high-quality equipment cannot be understated, evaluating costs within your budget constraints is also critical. Assess all aspects of ownership costs–purchase cost, maintenance expenses, and potential savings from increased efficiency or productivity gains. This holistic cost evaluation approach will help you make an informed decision that fits your budget while offering value.

Utilizing Professional Networks and Online Research for Decision-Making

Leveraging professional networks and conducting extensive online research can provide invaluable insight into your decision-making process. Professional networks can give firsthand accounts of experiences with specific equipment or suppliers, while online research can offer broader information about industry trends, product reviews, and supplier reputations. Together these methods of investigation offer a complete picture aiding in selecting the most suitable wet bench equipment.


Creating a comprehensive requirements list before purchasing a wet bench system is crucial in selecting the most suitable system to meet your requirements. This list guides you through the selection process, helping you focus on equipment that fulfills your specific operational requirements and will deliver high-quality performance. Your list should cover every critical element – technical specs, supplier credentials, and cost implications.

Contact Modutek if you need assistance developing a wet bench equipment requirements list for your manufacturing process.  Modutek is dedicated to providing equipment tailored precisely to meet the demands of customers to ensure they purchase equipment that meets their process requirements and optimizes performance and efficiency.

Using RCA Clean in a Wet Bench Process

Using RCA Clean in a Wet Bench ProcessEditor’s Note: This article was originally published in May 2015 and has been updated with new information and re-posted in August 2023.

The semiconductor manufacturing industry relies heavily on complex and precise processes to create electronic components we rely on every day. One such process is wafer cleaning – an essential step that removes unwanted particles or residue from silicon wafer surfaces that could otherwise compromise product quality or reliability. RCA Clean has been established as an industry standard wafer cleaning process due to its effectiveness in removing both organic and inorganic contaminants from silicon wafer surfaces.

RCA clean is a wet chemical process developed at Radio Corporation of America that involves a series of sequential steps. The objective is to prepare wafer surfaces for further processing while maintaining their integrity, an aim that aligns directly with the needs of Process Engineers.

Process Engineers focus on cost efficiency, reliability and cleanliness, and equipment design for precise process control. Equipment must be easy to use and deliver repeatable processes while meeting specific demands of a facility’s wet processes requirements.

Understanding RCA Clean in a Wet Bench Process

At its core, RCA Clean is a three-step cleaning process aimed at effectively cleaning silicon wafers.  Each step addresses different types of contaminants, such as organic residues, thin layers of native oxide, and finally, ionic contamination.

In the first stage of RCA cleaning, commonly referred to as Standard Clean 1 (SC-1), the mixture consists of:

  • 1 part NH4OH (ammonium hydroxide)
  • 1 part H2O2 (hydrogen peroxide)
  • 5 parts deionized (DI) water.

The SC-1 solution efficiently removes organic residues while simultaneously creating a thin silicon dioxide coating to provide additional protection to the wafer surface. The second step is to rinse with deionized water to remove the SC-1 solution.

Next, a dip into hydrochloric acid and deionized water mixture removes the thin oxide layer formed during Step One. Following this, the Standard Clean 2 (SC-2) begins. This mixture consists of:

  • 1 part HCl (hydrochloric acid)
  • 1 part H2O2 (hydrogen peroxide)
  • 5 parts DI water

This step helps remove metallic ions and again forms a thin silicon dioxide layer. The process concludes with another rinse and final dip into deionized water heated to 80°C to remove any remaining residuals.

RCA Clean is essential when it comes to achieving cleanliness, consistency, and process control in semiconductor manufacturing. However, the effectiveness of RCA Clean depends on the reliability of the equipment being used. This means using equipment that effectively supports RCA clean and ensures accurate and repeatable results for process engineers.

How Wet Bench Stations Facilitate RCA Clean

Modutek’s wet bench stations have been carefully designed to enhance the RCA clean process and alleviate some of the challenges Process Engineers encounter. Their design places particular importance on chemical compatibility, cleanliness, control, and safety – essential characteristics for successful wafer cleaning.

The wet bench stations at Modutek builds use materials resistant to the chemicals used in the RCA clean process. This ensures that the equipment remains unaffected by the cleaning solutions, allowing for an uninterrupted process and a longer lifespan.

As for cleanliness, Modutek’s stations are designed to minimize particle contamination. Their design limits air movement and deposition of particulate matter. Additionally, all wet bench station components, including process tanks, are designed for easy cleaning, ensuring optimal cleanliness at all times.

Modutek’s stations feature advanced automation capabilities for process control. These automated systems offer high-precision control over process variables like temperature, cleaning time, and concentration of cleaning solutions. This ensures accurate and repeatable RCA clean results while saving time and minimizing human errors. Process Engineers can use this level of oversight to achieve their desired results consistently while saving time and avoiding human mistakes.

The wet bench stations Modutek provides incorporate numerous safety features that promote maximum protection during semiconductor manufacturing processes.  This includes chemical-resistant materials, fire suppression systems, safety interlocks, and emergency power-off capabilities.

One way that Modutek’s wet bench systems use to facilitate the RCA clean process is through their temperature control system. For instance, for optimal cleaning results in the RCA Clean process, the SC-1 and SC-2 solutions must be maintained at specific temperatures to work effectively. Modutek’s wet bench stations have been specifically designed to precisely control the temperature of solutions, ensuring an optimal cleaning process.

Incorporating Megasonic Cleaning with RCA Clean

To further enhance the results of an RCA clean process, the use of Megasonic cleaning can be instrumental. Megasonic cleaning utilizes high-frequency sound waves in a liquid medium to generate microscopic cavitation bubbles. When these microscopic bubbles collapse, they create strong local shockwaves that efficiently dislodge and remove contaminants from silicon wafer surfaces. Megasonic cleaning combined with the RCA process can significantly enhance the silicon wafer cleaning process, offering the precision necessary for creating high-quality semiconductor devices with microscopic geometries.

Modutek’s wet bench systems are designed to incorporate Megasonic cleaning seamlessly. Wet process equipment with Megasonic capabilities can operate at multiple frequencies, allowing Process Engineers to optimize the cleaning process for their specific requirements. This provides optimal particle removal, improved cleanliness, and higher yield without damaging wafers or creating defects. With the integration of Megasonic cleaning, Modutek’s wet bench systems provide a better-optimized solution for wafer cleaning.

Cost Efficiency and Ease of Use with Modutek’s Wet Bench Stations

While cleanliness and process control are essential to Process Engineers, cost efficiency and ease of use should be considered when selecting equipment for wet bench processes. Modutek’s wet bench stations are designed with the end user in mind. They provide high-quality, reliable results at an exceptional value proposition. Modutek recognizes the importance of cost control for semiconductor manufacturing facilities and offers solutions that enhance productivity while reducing the total cost of ownership.

The robust construction and quality of Modutek’s wet bench stations extend their lifespan, meaning fewer replacement costs over time and reduced frequency of replacements. Furthermore, their precise control enables businesses to reduce waste while improving yield for higher profits and increased profitability.

Modutek’s wet bench stations are also designed for maximum operator convenience. The intuitive user interface and clear control parameters enable Process Engineers and equipment technicians to master operations quickly, reducing the learning curve and training time. This easy operation also reduces human errors that could otherwise result in costly process defects.

In addition, Modutek stands behind its products by offering top-tier customer service and maintenance support. This helps facilities maintain productivity with minimal downtime for their equipment. Modutek is dedicated to ensuring minimal equipment downtime to maximize productivity for customers. Modutek also provides on-site service, technical support, and spare parts to address any potential issues promptly and effectively.


The need for meticulous and consistent wafer cleaning in semiconductor manufacturing is paramount, and the RCA clean method, combined with Megasonic cleaning, provides an effective solution for ensuring optimal cleanliness. However, the success of these processes relies heavily upon the equipment utilized.

Modutek’s wet bench systems are carefully designed with precision, ease of use, and cost efficiency in mind, making them an ideal choice for the RCA cleaning process. They address key requirements and challenges faced by Process Engineers, such as chemical compatibility and effective process controls, as well as providing safety and maintenance support.

For Process Engineers seeking reliable, effective, and easy-to-use solutions for their wet process requirements, Modutek provides leading-edge solutions. With a strong track record and expert service, Modutek is a trusted name in the semiconductor manufacturing industry. Contact Modutek to schedule a free consultation to discuss your wafer cleaning process requirements.