How to Order a Wet Bench for Your Specific Process Requirements

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How to Order a Wet Bench for Your Specific Process RequirementsWet processing used in semiconductor manufacturing includes many complicated process steps which need to be taken into account when ordering new wet bench equipment. When selecting a supplier, experience and capabilities have to be evaluated. Physical requirements such as space and output volume are essential. The degree of automation required also plays a significant role. Finally, there are special requirements for specific processes that have to be evaluated. You need a competent manufacturer of wet bench equipment to help you get the wet process stations you need.

  1. Look for a Manufacturer with a Proven Track Record and In-House Capabilities

Manufacturers who can help you with your choice of a wet bench should have in-house expertise with a complete line of wet bench equipment, including their own software. An experienced manufacturer will be able to advise which stations satisfy your requirements and what options you should consider. In-house design and manufacturing capabilities allow the manufacturer to provide complete after-sales service and support.

  1. Make Sure Your Choices Don’t Impose Unwanted Physical Constraints

The chosen wet bench has to satisfy requirements for space, wafer size, and wafer throughput. If space is tight, a compact design or designs combining functions such as rinsing and drying can be considered. In any case, the station has to be able to process the proposed wafer sizes. Custom dimensions for equipment can be explored with a manufacturer that has customization capabilities.

Wafer throughput is often critical for the viability of the facility. It is influenced by the number of cassettes that can be processed in a bath and process duration. When projected throughput is borderline, an experienced manufacturer can often suggest special equipment, automation, or advanced process technology to reduce processing time and speed up production.

  1. The Degree of Automation Depends on How the Wet Bench Will Be Used

Wet benches for organizations such as research labs, small manufacturers, and high-volume manufacturing facilities have different automation needs. Labs often produce prototypes or small volumes for testing. A manual station may be the best solution for this kind of operation. Small manufacturers typically produce single units or small batches. A manual station could satisfy their needs, but a semi-automated station could allow them to run consistent batches while saving on the full-automation cost of robotics. High-volume operations will usually benefit from fully automated stations because they improve efficiency, reduce product defects and deliver excellent consistency over long runs.

  1. The Wet Bench Equipment Needs to Support the Wafer Manufacturing Process

Depending on the chemistry to be used, the selected wet bench equipment has to support the process. Wet process silicon wafer fabrication can use different chemical processes to clean, etch, develop and strip the wafers. Special equipment and accessories are used for various applications.

  • Acid process tanks are made from quartz or Teflon, while solvent processes require stainless steel tanks. Tanks are made with high-purity materials and are designed to minimize particle contamination.
  • Quartz tanks are used for cleaning, etching, and stripping. They can support high-temperature applications.
  • Teflon tanks are used for etching applications. They can be ambient temperature tanks or heated with re-circulation.
  • Silicon nitride wet etching requires special control features because adding de-ionized water to maintain the acid concentration can be dangerous.
  • Quick dump rinsers speed up the process while reducing the use of de-ionized water and avoiding particle entrapment.
  • Temperature-controlled circulating tanks are required for applications where the etch rate depends on the temperature. The baths are heated to achieve a higher etch rate and the temperature has to remain constant while the process is running.

Modutek Has the In-House Expertise and Capabilities to Help Choose a Wet Bench

As a leading semiconductor equipment manufacturer with over 40 years of experience, Modutek can recommend and provide the right equipment for your specific process requirements. Modutek has a complete line of wet processing equipment and can supply what you need and ensure it provides the performance you want. Contact Modutek for a free consultation and quote.

How Automated Controls Improve Silicon Wafer Manufacturing

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How Automated Controls Improve Silicon Wafer ManufacturingPrecise automated controls that are incorporated into wafer manufacturing equipment help manufacturers meet the challenges of higher component densities and compliance with environmental regulations. They provide excellent repeatability and accurate chemical dosages that precisely control the etch rate and the cleaning and stripping processes. Chemical neutralization and disposal are handled automatically with document generation to prove regulatory compliance.

In addition to delivering improved process control, the automation software can easily be customized for specialized process requirements or updated to reflect process changes. From the user inputs through to process equipment, the different components of automated wafer fabrication equipment work together to improve manufacturing outcomes.

An Intuitive User Interface Helps Operators Control the Process

A good user interface shows critical process variables and the status of necessary equipment. Operators can see how the process progresses and intervene to activate or shut down components if necessary. The interface can easily be updated when process requirements change or equipment is added. For fully automated stations, the process runs by itself after the operators select the sequence and set the initial conditions via the user interface.

Modutek automated stations use a touch screen with a graphical user interface (GUI). Operators see visual representations of the process and can control equipment from the screen. Because Modutek designs and programs the underlying software in-house, the company can easily change and update the GUI.

Automated Controllers Translate GUI Commands to Equipment Operation

Automation controls timed command sequences or keep process variables at the required set points. Sequences are programmed with Programmable Logic Controllers (PLCs) that output a sequence of commands when the operator issues the initial input. PLCs are programmed as a chain of outputs triggered by elapsed time or automated inputs. The chains are easy to program and change if needed.

Automation of process variables includes controllers for temperature, pressure, flow, or level. Modutek can integrate third-party controllers such as Omron or Allen Bradley for higher-level automation, such as machine control or special functions. This capability also allows Modutek to integrate its equipment into existing installations.

Data Logging Helps to Evaluate System Performance

When the Modutek automated stations are programmed to output key variables, the data can be assembled into reports helpful in evaluating performance and monitoring the program logic controls. The data can be collected over Ethernet and viewed remotely. Automated logs can be used to check values such as chemical use, output quantities, output yields, and chemical disposal details. Feedback from data logging is key to the optimization of the overall process.

Optional Equipment Interfaces Increase Application Flexibility

Modutek’s automated wafer fabrication equipment uses an optional interface that allows it to work with existing systems and components from other manufacturers. The SEMI Equipment Communications Standard/Generic Equipment Model (SECS/GEM) developed by the Semiconductor Equipment and Materials International (SEMI) organization governs the interaction of the software running the automated controllers and the semiconductor manufacturing equipment. Under the SECS/GEM standard, Modutek can customize its systems to meet customer requirements for updating its process lines or adding new equipment.

As a leading semiconductor equipment manufacturer, Modutek continuously innovates on equipment and automation. The company can supply individual pieces of equipment or provide turnkey installations. Modutek ensures its equipment meets customer needs and performs as expected in both cases.

Chemical Handling for Wet Processing Equipment

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Chemical Handling for Wet Processing EquipmentBecause wet processing of silicon wafers uses different types of chemicals, semiconductor manufacturing facilities need chemical handling equipment to store, deliver and dispose of the chemicals. A complete chemical handling system takes care of all aspects of chemical use and ensures chemicals are delivered to the process when and where needed.

For corrosive, toxic, or flammable chemicals, safe handling is critical. Most of the chemicals used in wet processing can’t be released into the environment without additional treatment. Neutralizing dangerous chemicals on site or storing them in safe containers until they can be transported to a treatment facility must be documented to comply with local regulations.

Since chemicals are often dangerous to the employees operating wet processing systems, the chemical handling equipment has to be designed to minimize spills and reduce employee exposure to chemicals and their fumes. A comprehensive chemical handling system can improve workplace safety, reduce spills and waste, and make chemical processes more efficient.

Chemical Delivery Systems Provides Your Process the Chemicals It Needs

Chemical delivery systems store the chemicals safely and then deliver the right quantities, mixtures, and concentrations directly to the production line. The amount of chemicals delivered has to be precise and repeatable. Successful wet processing often depends on the right mixture or concentration because etching, stripping, and cleaning can vary with the amount of chemicals in the bath. When processing batches, the amounts delivered must be precisely the same for each batch. With continuous processing, the chemicals delivered can’t vary over time.

Modutek has a complete range of chemical delivery equipment, from high volume systems for large continuous production lines to small batch operations. Chemicals can be stored remotely in large totes with a load cell interface or in 55-gallon drums near the wet process station. Modutek’s SolidWorks Simulation Professional and SolidWorks Flow Simulation applications can calculate the exact quantities of chemicals required, and the chemical delivery systems provide precisely the calculated amounts. These systems ensure that chemical handling and process repeatability are excellent.

Modutek’s Collection Systems Remove Used Chemicals from Processing Stations

Once a wet process such as cleaning, etching, or stripping is complete, the used chemicals must be removed from the process stations and collected. Chemicals can be stored in safe containers and sent to a company specializing in neutralizing and disposing of hazardous chemicals, or they may be neutralized on-site.

To collect the chemicals from processing stations, chemical lift stations can pump the chemical waste from the process tank to a storage container. Chemical carts, also called pump carts or collection carts, can be moved near the process tanks to empty smaller amounts of chemicals. Storage can range from small carboys to large collection tanks. For small volumes, waste chemicals can be pumped directly into a five-gallon DOT-approved carboy for subsequent shipping to an off-site neutralization facility.

Acid Neutralization Systems Ensure Compliance with Environmental Standards

Many wet process semiconductor manufacturing steps use strong acids in their process baths. The used acids must be disposed of safely without risks to employees, the general public, or the environment. Local regulations specify how acid waste must be treated to ensure that disposal meets these requirements.

As regulatory compliance becomes more complex, the costs of disposing of chemical waste off-site are increasing. Modutek can provide self-contained acid neutralization systems that are inexpensive to operate. These systems add neutralizing chemicals to the acid waste and track chemical use, waste pH, and discharge quantities. The systems can generate documentation for regulatory compliance and safely dispose of the neutralized waste.

Modutek Offers In-House Expertise for Selecting Chemical Handling Equipment

Modutek can help customers choose the right chemical handling equipment for their facility. In-house experts at Modutek can recommend equipment from a full line of chemical handling systems. Modutek can customize equipment for special applications and ensure that the systems meet customer needs. Contact Modutek today for t a free consultation to discuss your chemical handling needs.

Easy to Install Wet Processing Equipment for R & D

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Easy to Install Wet Processing Equipment for R&DWhen research labs need to produce semiconductor prototypes or small quantities for testing, it’s often too expensive to place an order with a wet process production line supplier or to purchase complete wet process stations. Modutek has developed innovative tabletop models that are less expensive than full-sized wet process manual stations and take up much less room. They support the most common wet process cleaning, etching, and stripping steps, and Modutek can customize the units for special applications. The new Modutek tabletop units are easy to install and ideal for small-quantity R&D applications.

Modutek’s Table Top Units Are Feature-Rich and Versatile

Modutek has designed its new tabletop wet processing units to satisfy various R&D needs. The Teflon tank models support acid process steps such as KOH etch and buffered oxide etch (BOE), while stainless steel models support solvent process steps such as solvent resist strip. Tanks are available for ambient temperature or temperature-controlled operation, and they can be static or re-circulating with a filter and an all-Teflon fluid path. The temperature-controlled models have precise controls with rapid and even heating of the bath. The tanks come with temperature and level alarms and a drain interlock.

The compact and simple design of the tanks makes them easy to use, and operators can quickly get excellent results. The standard units that support the most common wet process steps allow the production of many different types of semiconductors. Modutek can customize its tabletop units to support additional silicon wet etching processes as required.

Modutek’s Table Top Units Support KOH Etch

KOH etching is popular because it delivers precise results using a relatively safe process. As such, it is well-suited for tabletop R&D applications. The etch rate depends on potassium hydroxide (KOH) concentration and temperature in the process solution. The etch direction can also be influenced by the silicon lattice’s orientation and the silicon’s boron doping. Different etch control strategies allow operators to etch various shapes into the silicon wafer.

The concentration of KOH may vary from 10 percent to 50 percent, but it is usually at around 30 percent. The orientation of the silicon crystal lattice means that the etch rate is faster in one direction, and Boron doping stops the etch progress in the direction in which the boron is found. These control factors are determined by the design of the etch shapes before the start of the process. Once etching has begun, the temperature allows operators to further control the etch rate and influence the shapes of the etched cavities. Because KOH etches can be controlled in different ways, it is the etch process most commonly used in Modutek’s tabletop units.

Using Modutek’s Table Top Units for Sub-Ambient BOE Etch and Solvent Applications

BOE etching is used to etch patterns in silicon dioxide films or to remove such films from the silicon wafer surfaces. The etching solution contains hydrofluoric acid, and a low temperature reduces consumption. The units that support BOE are the circulating, filtered models that are also fitted with a heater/chiller. Sub-ambient operation down to 10 degrees centigrade is possible.

Solvents used in semiconductor manufacturing steps, such as solvent resist strip, require stainless steel tanks and special safety features. Solvents, such as acetone, are flammable, and Modutek’s tabletop units include measures to prevent fire and explosions. Modutek can customize solvent and acid tabletop units to support other wet-process applications and add special features as needed.

Modutek Can Provide Custom Units for R&D Applications

Modutek has extensive in-house experience designing and building silicon wet etching equipment. If you need equipment to support R&D functions, tabletop units are an excellent option that can be customized to support many wet-process applications. Contact Modutek for a free consultation to discuss your application requirements.

Equipment Innovations Improve Silicon Nitride Etch Processing

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Equipment Innovations Improve Silicon Nitride Etch ProcessingWhen silicon nitride wet etching is used to etch masks on silicon wafers, precise control of the etch rate is important. If the etch rate varies, the mask may not be correct and the microscopic structures to be created in the silicon may not have the right shape or depth. In the silicon nitride wet etching process, the etch rate depends on both the temperature and the concentration of the etching solution. Both may vary as the process progresses and precise control becomes difficult. An ideal control strategy maintains both the concentration and the temperature at known levels. The etch rate then remains constant and the mask is etched accurately according to the applicable specification.

Silicon Nitride Mask Etching Is Effective but Hard to Handle Safely

Semiconductor manufacturers and research labs use silicon nitride wet etching because the process etches the mask material quickly and reliably. A mixture of 85 percent phosphoric acid and 15 percent deionized water is heated to the boiling point. As the mixture boils, it releases steam that reduces the amount of water in the etching solution. As the concentration of phosphoric acid rises, so does the boiling point, the temperature of the mixture and the etch rate. To keep the process under control, deionized water has to be added to bring the concentration back down.

Adding water to phosphoric acid is exothermic. To prevent a sudden increase in temperature, water has to be added in small amounts, but if too many small amounts are added to the mixture, it will stop boiling. The water then forms a thin film on top of the mixture and eventually mixes with the phosphoric acid all at once, leading to a sudden temperature spike and a possible explosion. A complex control system with variable set points can ensure safe operation but control of the etch rate is poor.

Modutek’s Silicon Nitride Etch Controls Are Simple and Precise

Modutek addresses the control issues of silicon nitride wet etching by heating the etch bath continuously. An always-on heater heats the original 85/15 percent phosphoric acid/deionized water mixture to its boiling point of 165 degrees centigrade. As the mixture loses steam and the concentration and temperature both start to rise, a thermocouple detects the slightly increased temperature and triggers the addition of a small amount of deionized water. The added water is immediately mixed into the etching solution by the boiling action. The amount added restores the concentration and keeps the temperature at the boiling point.

Modutek has refined this control concept to accurately maintain the etching solution exactly at its original concentration and at its boiling point. As a result, with both the concentration and the temperature remaining constant, the etch rate remains predictable and constant as well. Mask etching is reliable and the final mask has precisely the desired characteristics.

Because the Modutek control strategy relies on maintaining the etching solution at the boiling point, the control system has additional safety features to identify dangerous conditions that could result if the mixture stops boiling. Two thermocouples detect the presence of steam over the hot acid and acid overtemperature. If there is no steam, the mixture is no longer boiling. If the acid temperature is too high, the solution is no longer being maintained at the original boiling point. In either case, the process is shut down because equipment failure is likely and a dangerous condition may be present.

Modutek Provides a Complete line Equipment Solutions

Modutek offers a complete line of silicon wet etching equipment and works with customers to develop innovative solutions to their problems. The silicon nitride etching control system improves etching performance and results remain consistent over different batches. The number of defective products is reduced and product quality increases. When customers purchase etching systems and other equipment, Modutek will ensure they meet their requirements. Contact Modutek for a free consultation to discuss your specific process requirements.

How Advanced Ozone Cleaning Reduces Costs and Improves Wafer Yields

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How Advanced Ozone Cleaning Reduces Costs and Improves Wafer YieldsWhen ozone is used to clean silicon wafers, it reduces the use of aggressive chemicals and it can decrease the wafer particle count. Modutek’s advanced ozone cleaning process can clean more quickly than many chemical-based processes and it delivers other benefits. Ozone is used to remove organic contaminants from wafer surfaces in either the Coldstrip sub ambient process or the Organostrip process. Either process can reduce overall wafer fabrication costs and improve manufacturing facility performance.

Advanced Ozone Cleaning Outperforms Chemical Stripping

With increased regulation of the use of dangerous chemicals and pressure on businesses to make their operations more environmentally friendly, Modutek developed the advanced ozone cleaning processes to help semiconductor manufacturers and research labs reduce chemical use. Ozone is introduced in Modutek’s DryZone system in compact units using the Coldstrip or Organo strip processes. Both cleaning methods also feature a reduced particle count compared to chemical cleaning methods.

In the Coldstrip process, wafers are first rinsed with deionized water to remove soluble non-organic contaminants. The process operates at four to ten degrees centigrade. After the rinsing, ozone is introduced into the chamber and combines with the carbon of the organic compounds on the wafer surfaces. The ozone-carbon reaction forms carbon dioxide, leaving wafers clean and almost free of particles.

The Organostrip process also uses ozone but operates at ambient temperature. Ozone is introduced into the process dissolved in acetic acid, a mild solvent in which ozone has a very high solubility. The wafers are rinsed with the ozone-acetic acid solution and the high level of ozone rapidly oxidizes the organic contaminants. The waste products of the process do not require special treatment. Both processes work quickly and feature excellent cleaning performance with low particle counts.

Changing to the Advanced Ozone Cleaning Process Delivers Substantial Benefits

The major benefits of changing from chemical cleaning to an advanced ozone cleaning process is a reduction in the use of toxic chemicals and improved cleaning performance with a lower particle count. These two factors are at the root of additional benefits resulting in cost savings, better yields and improved safety for employees.

Reduced Use of Chemicals

When the use of toxic chemicals is reduced, there are cost reductions in addition to savings resulting from fewer chemical purchases. Other savings include reduced costs for chemical storage, handling and disposal. Employees benefit from lower exposure to harmful chemicals and from increased workplace safety because there is less danger of spills or accidents.

Regulatory compliance costs are also reduced. As environmental regulations become more onerous, costs rise and compliance becomes more difficult. Reduced chemical use results in lower compliance costs, and a more environmentally friendly operation helps improve community relations and the environmental reputation of the business.

Lower Particle Contamination

Lower particle counts are the result of better cleaning performance. Particle counts play ang increasingly important role in wafer structures that are smaller and more tightly packed. Even a single particle can block a conducting path or the etching of a tiny detail. Fewer particles means a lower rate of defective products and higher yields. Product quality and longevity may also be improved.

Improved Cleaning Performance and Wafer Yields with Less Equipment

In addition to a lower particle count, the improved cleaning performance of the advanced ozone cleaning process results in shorter cleaning times within a smaller footprint. Modutek’s DryZone units used for the ozone cleaning process are compact and take up less space than the corresponding chemical cleaning stations. Cleaning is more rapid resulting in higher throughput. As a result of these benefits, the overall performance of the silicon wafer fabrication facility can improve substantially.

Modutek Provides Advanced Equipment for Manufacturers

As one of the leading semiconductor equipment manufacturers, Modutek can advise customers on how to implement a change to ozone cleaning. Modutek offers a free consultation and quote on their equipment, and ensures their equipment will support processes that meet customer requirements.

Why Stainless-Steel Stations Are Needed for Solvent Processing

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During silicon wafer fabrication, BEOL (Back End of Line) processes may require solvent-based stations to ensure compatibility with semiconductor manufacturing steps. FEOL (Front End of Line) acid-based chemistry may not be suitable for BEOL finishing. Instead, stainless-steel stations with solvents such as acetone, IPA (Isopropyl Alcohol) or EDP (Ethylenediamine Pyrocatechol) complete wafer etching, stripping, and cleaning. Stainless steel is used for these stations because it is impervious to solvents and because it reduces the risk of fire when solvents are highly inflammable.

Why BEOL Wafer Fabrication Steps May Require Solvent-Based Stations

A wet bench FEOL fabrication starts by repeatedly cleaning, etching, and stripping wafers to build microscopic structures in the silicon. The common acid-based processes used include RCA clean, with chemicals such as hydrogen peroxide and hydrochloric acid; KOH etch, with potassium hydroxide; and Piranha clean, with sulfuric acid. As well as etching the silicon wafers, these chemicals remove both organic and metallic impurities from the surfaces of the wafers, leaving them completely clean and pure for the next process steps. The structures etched during these FEOL steps form the physical parts of the semiconductor components such as transistors.

In the BEOL process steps, the transistors and other components are interconnected and connected to plugs or sockets that interface with outside signals. The connecting paths are metallic, usually made of copper or aluminum, so that they can conduct electrical charges efficiently. Once the metallic paths are deposited on the silicon wafers, acid-based processes can no longer be used because the acidic chemicals damage the metallic paths. Instead, a solvent manufacturing process is used with solvents that are compatible with metals but can complete the silicon wafer processing and produce the final semiconductor components.

Solvent-Based Wet Benches Need Special Safeguards and Protection

The solvents used in wet bench stations are highly inflammable and operators have to be protected against being exposed to fumes or contact. Stainless steel stations using inflammable solvents have to be explosion-proof and satisfy the Class 1, Division 2, Group D explosion-proof standards. They should be designed with fire suppression and wired to the NFPA 70 and 79 standards. An emergency power off mushroom button with safety interlocks helps protect operators if something goes wrong and PVC safety shields help prevent accidental contact with the chemicals. An experienced wet bench manufacturer can ensure that these safety regulations are followed and that operating the solvent stations is as safe as possible.

Modutek’s Stainless Steel Solvent Stations Operate Safely and Meet Customer Requirements

With over 30 years of experience in wet process technology, Modutek designs and builds stainless steel solvent stations to operate safely and meet customer requirements. These stations are made of 304 stainless steel and are wired to the NFPA 70& 79 standards. Fire suppression is included and extensive customization is available.

Stations can be fully automated, semi-automatic, or manual. Fully automated stations reduce operator error and feature excellent repeatability, both for batch processing and for keeping variables constant over an extended period of continuous operation. Semi-automatic stations provide many of the benefits of fully automated operation but at a lower cost. Manual operation is ideal for testing or for prototypes. Once the process has been optimized with manual adjustments, automatic operation can reduce defects and improve facility performance. SolidWorks Simulation software is available to analyze the process and calculate chemical flows. The software can improve etching performance, improve yields and increase throughput.

On the performance side, Modutek stainless steel stations can operate with temperatures from thirty to one hundred degrees centigrade, heat up the bath at a rate of 2 degrees centigrade per minute, and maintain the temperature with an accuracy of plus/minus 1 degree centigrade. Heating elements are four-sided and a process temperature controller is available as an option.

Modutek’s Expertise in Wet Process Equipment

 Modutek designs and builds their own wet process equipment in-house using their own expertise and experience. Their wet bench equipment is designed to meet high quality standards, and are customized to meet specific customer requirements. Solvent-based stainless-steel stations deliver top performance for BEOL processing and Modutek can ensure the equipment meets specific customer needs. Contact Modutek for a free consultation to discuss your specific process requirements.

How the Piranha Etch Process Improves Silicon Wafer Cleaning

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While the Piranha solution quickly removes organic residue from silicon wafers, the process is difficult to control and may produce explosive gas mixtures. The Piranha solution is made up of one part hydrogen peroxide and three parts sulfuric acid, although the ratio may vary for specific applications.

The mixture is exothermic and the heat released when the hydrogen peroxide is added to the sulfuric acid drives up the temperature of the solution towards the normal process operating temperature of 130 to 180 degrees centigrade. Both the temperature and the concentration may vary, reducing the useful lifespan of the solution. When the challenge to control temperature and maintain the concentration is met, the Piranha solution can deliver superior silicon wafer cleaning performance.

Spiking the Piranha Solution Can help Maintain Concentration

The hydrogen peroxide in the Piranha solution is not stable and decomposes to produce water. The rate of decomposition is higher the higher the temperature, and the water dilutes the solution. Operators can compensate for the lower concentration by periodically spiking the solution with additional hydrogen peroxide. As hydrogen peroxide is added, the temperature rises, and more hydrogen peroxide decomposes to form water. This interdependence of the concentration with the temperature complicates keeping a tight control on the process, but spiking the Piranha solution lengthens the solution’s lifespan from a few hours to about one day.

Modutek’s “Bleed and Feed” Method Increases the Piranha Solution Lifespan

Modutek has developed an innovative solution to the control and lifespan issues of the Piranha process. The company uses quartz tanks with a “clean” and a “dirty” tank to provide pre-mixed Piranha solution to the active process. Silicon wafer cleaning takes place in the “dirty” tank while the clean tank has a Piranha solution with a programmable concentration. When the concentration of hydrogen peroxide drops in the “dirty” tank, a small amount of the low-concentration solution is drained from the tank and an equal amount is added from the “clean” tank. Instead of the destabilizing spike of hydrogen peroxide, the small but frequent addition of pre-mixed fresh Piranha solution keeps both the concentration and temperature stable and makes possible a tight control of the process, significantly prolonging lifespan.

The “Bleed and Feed” Method Delivers Important Benefits

Modutek’s “Bleed and Feed” method is fully programmable, allowing operators to adapt it to any application to deliver improved silicon wafer cleaning. The concentrations of the “clean” and “dirty” tanks, the amount of the “bleed” and the amount of the “feed” are all independently adjustable so the desired concentrations can be maintained for an extended period. Specific benefits of the “bleed and feed” method include the following:

  • Predictable strip rate because both the temperature and the concentration are tightly controlled.
  • Programmable settings allow a flexible operation.
  • Risk of an explosion from spiking with too much hydrogen peroxide is reduced.
  • Longer solution lifespan results in reduced use of chemicals.
  • Reduced costs for purchase, storage, and disposal of chemicals.
  • Reliable process parameters result in excellent repeatability between batches and accurate maintenance of process variables over extended operation.
  • Reduced downtime because the Piranha solution has to be replaced less often.
  • Safer operation because the process is maintained in a stable equilibrium.

With a more stable Piranha process, silicon wafer cleaning is improved with less contamination and fewer particles. Product defect rates are lower and customers will see higher yields. Overall wet process line performance is improved, with lower costs and better output quality.

Modutek Provides Innovative Solutions for Wet Processing Requirements

Modutek continues to build on its experience in wet process technology and has in house expertise to develop innovative solutions for their customers. The Piranha solution “bleed and feed” method lets customers achieve their production goals more easily. Modutek provides solutions that meet customer needs and ensures that the delivered equipment performs as required. Contact Modutek for a free consultation to discuss the equipment needed to support your specific process requirements.

How Quick Dump Rinsers Improve Wet Processing Results

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While effective and rapid rinsing with a low particle count remains a key benefit of quick dump rinsers, reduced water usage is also becoming more important. Special design measures can lower the amount of water required to rinse the silicon wafers while retaining fast and efficient operation with a low level of particle contamination.

Low water consumption is especially important in some regions such as the Western U.S., where a long-term drought makes water conservation mandatory. Even in other areas, a reduced use of the deionized water used in silicon wafer fabrication saves money and is environmentally responsible. Modutek has pioneered the design of quick dump rinsers that feature efficient use of deionized water, fast operation, and low particle entrapment.

Quick Dump Rinser Benefits that Incorporate Reduced Water Usage

Modutek’s quick dump rinsers feature a state-of-the-art design for efficient operation while minimizing rinse time, reducing the particle count, and keeping deionized water usage to a minimum. Modutek’s quick dump rinsers offer the following characteristics:

  • Efficient Rinsing. The units have dual spray manifolds and low misting nozzles for quick and complete rinsing away of chemical residues.
  • Nitrogen Bubbler. The bubbler generates nitrogen bubbles as the tank fills, removing additional contaminants and particles.
  • 360 Degree Overflow Weir. As the dislodged impurities rise to the surface, they are flushed away across the overflow weir and out of the tank.
  • Programmable Water Use. Modutek’s quick dump rinsers can be programmed to use less water.
  • Contoured Bottom. The rinser bottom is contoured around a wafer cassette, reducing the amount of water required.
  • Large Machined Trap Door. The machined trap door doesn’t need gaskets or seals that could trap particles, and the large size lets water drain rapidly.
  • Polypropylene Construction. High-quality smooth polypropylene construction ensures that the tank is not a source of contamination with new particles.
  • Automatic Dump and Refill. The rinsing controller can be set to automatically dump and refill every two hours, reducing bacterial growth and minimizing the possibility of contamination.
  • Optional Reclaim System. An optional reclaim system further reduces water consumption and lowers costs.
  • Variety of Standard Sizes. Modutek offers seven standard tank sizes for their quick dump rinsers, and can accommodate many special customer needs.

Modutek has designed the quick dump rinser to operate as a stand-alone unit or for integration into a silicon wet etching process line. The rinser can improve the overall performance of the line and lower costs while reducing the number of defective products.

Benefits of Using Modutek’s Quick Dump Rinser

Modutek’s design is based on extensive experience working with wet process equipment to address key customer concerns. Benefits include the following:

  • The reduced water consumption due to rapid rinsing and a water-conserving design lowers costs and reduces the environmental impact.
  • The machined trap door and laminar flow of rinsing water reduce the particle count and improve output quality.
  • The smooth polypropylene construction avoids additional contamination and reduces the percentage of rejects.
  • Quick rinsing allows increased throughput for the production line and reduces costs.

From its close working relationship with customers, Modutek can address the challenges manufacturers often have with meeting higher product densities, smaller silicon structures, and increasing regulation with using chemicals and water. Modutek continuously works to improve silicon wafer processing capabilities, while keeping in mind the overall costs of ownership and efficient wafer processing.

Modutek Provides Innovative Solutions to Meet Customer Needs

Modutek’s quick dump rinsers represent years of innovative design and development. These systems let semiconductor manufacturers and research facilities reduce water consumption while increasing output and reducing the number of product defects. Overall facility performance is improved through cost reduction and improved output quality. Contact Modutek for a free quote or consultation to discuss your specific processing requirements at 866-803-1533 or email [email protected].

How to Select an Acid Neutralization System to Reduce Chemical Disposal

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When industrial processes such as semiconductor manufacturing use chemicals, the chemical waste needs to be treated before disposal. Chemical waste treatment can be handled on-site with an acid neutralization system or companies can use outside service providers to pick up the waste and properly dispose of it.

Modutek’s acid neutralization systems are designed for easy and flexible installation along with reliable operation and low chemical consumption. The systems make it easy for customers to avoid the costs of hiring disposal companies by treating chemical waste in-house. For many industrial processes, the chemical waste treated with an acid neutralization system is safe enough to drain into the local sewer system.

Continuous Flow Versus Batch Neutralization Systems

For most large industrial operations, a continuous flow acid neutralization system is the best solution. The waste chemicals from a process are produced continuously and they are automatically treated. A continuous flow of 5 to 100 gallons per minute (GPM) can be neutralized. Smaller industrial facilities often operate in batch mode where small quantities of used chemicals need to be disposed of. Modutek’s acid neutralization systems treat and neutralize chemicals using the continuous flow method.

Flexible Installation Means Modutek Systems Are Suited for Many Different Applications

To reduce chemical disposal via an outside service provider, an in-house neutralization system has to be flexible and easy to install. Cost-effective systems have to feature low chemical consumption for complete neutralization allowing disposal into a local sewer. Modutek’s acid neutralization systems satisfy these requirements and can save customers money by reducing chemical disposal costs.

Additional installation features for various service applications include the following:

  • Indoor or outdoor installation
  • Working volume up 4000 gallons
  • 110% Secondary containment tank for extra safety
  • Final discharge sample tank with pH probe and chart recorder for compliance purposes
  • Acidic or alkaline chemical waste treatment in two or three stages
  • Fully automatic operation with a touch screen monitor
  • Unitized construction with larger systems skid-mounted
  • Microprocessor-based pH controls with a comprehensive alarm system

Modutek’s acid neutralization systems are designed to fit into existing process lines with just a plumbing connection and electrical hookup. Once installed, the systems offer problem-free chemical waste neutralization and disposal.

Sensors, Meters, and Automation Help with Ease of Operation

Modutek acid neutralization systems are designed to work reliably in fully automated mode while sensing chemical waste composition and triggering alarms when key variables show abnormal values. Electronic chemical metering pumps supply the correct amounts of neutralizing chemicals while Signet pH probes and transmitters monitor the composition of the chemical waste. Signet paddle wheel flow sensors and signet 9900 flow meters/totalizers send their signals back to a PLC that controls alarms. The systems are designed to work independently while providing readouts for operators tracking the process. Chemical use, discharge pH, overall flow, and triggered alarms are recorded. Operators can make sure that discharged waste stays within the environmental regulatory framework and can use the recorded data to demonstrate compliance with proscribed values.

Modutek’s Expertise in Chemical Processing and Neutralization

By working closely with customers and industry partners, Modutek provides continuous innovative products to meet customer needs. Modutek has its own in-house expertise to evaluate specific applications and make recommendations. After identifying process requirements, Modutek can make suggestions and offer systems from its complete line of chemical handling equipment. For a free quote or consultation to discuss your chemical processing and neutralization requirements contact Modutek at 866-803-1533 or email [email protected].