Reasons to Use a Wet Bench Manufacturer with In-House Expertise

When dealing with third-party distributors who offer wet bench stations built by someone else, customers often pay more and get less. A wet bench manufacturer that designs and builds its own wet bench equipment in-house develops the expertise and capabilities needed to satisfy customer requirements. The manufacturer can respond directly to customer requests and design tailored or full custom solutions to meet specific requirements. With a wet bench manufacturer who has in-house expertise, customers can get exactly what they need.

Customizing Wet Bench Designs to Match Customer Needs Requires In-House Expertise

Semiconductor manufacturers and research labs often work with tight specifications that can’t be satisfied with standard wet bench stations. Customization requirements can range from space limitations to special robotics and software to control specific processing requirements. When manufacturers carry out their own design work, they are aware of the possibilities and limitations of specific semiconductor manufacturing processes. They can then easily advise customers what solutions are available and help choose the best one. Customers end up with optimized designs for equipment that works the way they want.

Building Custom Wet Bench Stations Requires Extensive In-House Manufacturing Experience

When wet bench manufacturers carry out their own design work, they know how to build what they design. Their designs are based on extensive in-house manufacturing experience gained over many years of building wet bench stations. They know what works and have been able to feed this experience back to their design engineers. With suppliers that carry out both design and manufacturing in-house, customers get wet bench equipment that is designed to their specifications and that is based on extensive manufacturing experience.

Wet Bench Manufacturers Can Provide Superior Customer Service and Support

With in-house design and manufacturing personnel, companies can provide knowledgeable customer support and after-sales service. When design, manufacturing, and process expertise resides in-house, service personnel know who to call if they run into problems. Support and service people will already be familiar with their own standard equipment and they have direct access to the design and manufacturing specialists that can guide them to find the best solutions for after-sales issues.

For wet bench technology, it’s especially important that the manufacturer also designs and writes the software that runs the process. Automation is becoming an increasingly important part of wet process equipment. Even if process steps are initiated manually, the software may be responsible for timing and dosages. For fully automatic stations, the software runs the whole process. Only the specialists who write the software can perform effective troubleshooting if there are unexpected operations or results. The wet bench manufacturer’s in-house expertise has to include the software.

Modutek Has Extensive Expertise Based on Long-Term Design and Manufacturing Experience

With over 40 years of experience in designing and building wet bench stations for industrial clients, Modutek is a leading wet bench manufacturer. Modutek works closely with customers to develop new technical solutions for current problems. In addition, Modutek actively leads technological innovation in fields such as wet bench process control, efficient chemical use, and reduction in particle contamination of silicon wafers. When customers identify new issues with semiconductor manufacturing, Modutek can often contribute to finding the best solutions.

Based on this long-term experience, Modutek personnel have developed extensive expertise in wet bench technology. The company designs its own equipment, including the development of its automation software. Wet bench stations are assembled and tested in-house at Modutek’s facility in San Jose which allows for easy customization. Modutek has a product line of standard equipment, including process tanks, chemical handling equipment, and complete wet process stations, the company can change dimensions, materials, robotics, process variables, and operator interfaces in accordance with customer requirements. In-house expertise is the key to these capabilities.

Why Ergonomics and Safety Are Important in Wet Bench Station Design

Because semiconductor manufacturing with wet bench technology uses dangerous chemicals in many of the process steps, ergonomic design helps keep employees safe. Toxic and corrosive chemicals such as hydrochloric acid are used to clean, etch and strip silicon wafers in wet process stations. Ergonomics helps ensure that operators don’t have to strain or overextend themselves when carrying out their work.

A safe working environment means that safety measures such as interlocks and alarms are in place, the risk of fire and explosions are minimized, and access to hazardous areas is restricted. Adequate employee training is a key factor in handling dangerous chemicals safely. Wet bench design has to take into account ergonomic factors when creating operator interfaces and safety measures to ensure the risks inherent in wet process operation are reduced to a minimum.

Ergonomics and Safety Can Increase Productivity and Employee Satisfaction

When the design of wet process stations makes it easy for operators to run each process step, increased comfort and safety allows them to focus on the work instead of worrying about possible mishaps. Safety has to be built into the stations, with prominent signaling of hazardous conditions such as spills, the use of explosion-proof measures such as low power electric signals, and the avoidance of flammable materials.

The Semiconductor Equipment and Materials International (SEMI) Safety Guidelines detail some of the measures that are required for wet benches, including guidelines for many aspects of semiconductor manufacturing. For example, SEMI S2 is a standard on safety labeling, safety interlocks, emergency shut down, electrical design, and ventilation. The SEMI S8 standard gives safety guidelines for the ergonomics of operation, maintenance, and service. Experienced semiconductor equipment manufacturers follow these guidelines because they realize that it makes sense to provide operators with a safe workplace and ergonomically designed equipment.

Modutek Incorporates Ergonomics and Safety Guidelines Into Their Wet Bench Station Design

Both Modutek’s standard lines of wet process equipment and customized versions are designed and built to the SEMI guidelines. Ergonomic design measures include features that make it easy for operators to carry out their work. Safety guidelines are followed so that the operation with the dangerous chemicals used in the process remains safe. For each wet process station, the ergonomic and safety requirements are either met or exceeded.

For example, ergonomic design has wafer loading trays brought to the front of the wet bench, making it easy for operators to load the trays. The operator interface is mounted on a swing arm, allowing operators to move it into different positions so they can see it while monitoring the process. The same thinking carries over to maintenance and service, where designs also respect ergonomic guidelines.

Modutek pays special attention to the safe design aspects of wet benches. Stations dealing with flammable substances are certified as hazardous locations to Class 1 Division 1 or Division 2. Safety interlocks are paired with process monitoring, leak detection, and alarms for dangerous conditions. Electrical controls are designed with low levels of power too weak for possible sparks to set off an explosion. Wiring satisfies NFPA 70 and 79 and there is an emergency off mushroom button.

Depending on the process, additional safety measures can include auto-lids to seal off the chemicals, gaseous automatic fire suppression systems, and access controls to ensure that only qualified operators can run the process. PVC safety shields, N2 head case purging and a deionized water hand spray may also be used.

Based on their extensive experience with the safe operation of wet benches, Modutek implements such ergonomic and safety measures while maintaining excellent operational reliability and superior yields. The complete line of Modutek wet process equipment is designed and built to the highest safety standards while delivering top-level performance for customers.

How Automated Wafer Fabrication Equipment Optimizes Process Control

Fully or semi-automated silicon wafer fabrication equipment can reduce errors and improve repeatability in wafer processing while at the same time increasing flexibility. Automatic controls let operators change process parameters if required for different processes or for process optimization.

Once a process runs in an optimized fashion, automated controls allow operators to make sure that the process continues to run the same way, either in a continuous mode or in batch processing. Automatic controls can ensure that an error-free process increases productivity, improves output quality, and reduces waste.

Automatic Controls Increase Operating Flexibility

Automatic controls use programmable software to specify how process steps operate and their sequence. The software determines the timing, chemical dosages, wafer transfers between stations, waste chemical neutralization, and chemical disposal. Once operators have programmed a process, they can carry out test runs and find where settings could be changed to improve the process results.

This means a process can be adapted to reflect changing requirements or can be changed so it produces better outcomes. At the same time, the process software in both semi-automated and fully automatic stations controls robotics that handles the wafers and reduce particle contamination. Automatic controls with the associated robotics can save money and produce semiconductor products with fewer defects and closer adherence to specifications.

Automated Operation with Robotics Contributes to Optimized Operations

Robotics handle and transfer the silicon wafers are a key part of the automated semiconductor manufacturing operations. For fully automated lines, multiple robots will hand the wafers down the process line. The robots have to operate to an extremely high level of precision to avoid damaging the delicate wafers and to place them precisely in the right locations. With the right robotics, properly programmed and fully automated, a semiconductor processing line can increase throughput and perform reliably to meet delivery times and volumes. Optimized process control combined with robotic speed and reliability can reduce costs and improve semiconductor fabrication facility performance.

For semi-automatic wafer fabrication equipment, the robotics generally handle less processing, however, Modutek has developed a new rotary rotation robot that can handle more process steps. The use of the rotary rotation robot can reduce the overall length and footprint size of a conventional station in a space-saving design. This allows manufacturing facilities and research labs with limited space to install semi-automatic fabrication lines using smaller stations with new robotics. As is the case for fully automated stations, semi-automatic controls and robotics can deliver increased speed, higher reliability, and improved facility performance.

Selecting the Right Automation Solution

Whether it is a fully automated process line or semi-automatic wafer processing equipment, automation can improve chemical handling and the cleaning and etching of silicon wafers. Software control ensures that chemical mixtures are correct, the timing of process steps is accurate and wafers are moved and transferred with a minimum of particle contamination. This allows wafer fabrication processes to be accurately completed with optimum efficiency and generates fewer defective components.

With more accurate process control, etch rates and yields can be higher and comprehensive tracking of variables delivers a complete picture of the process. Once the automated process has run for a large number of jobs, a saved software library gives manufacturers the ability to reuse previous configurations and the flexibility to make specific changes in the previous process runs.

Modutek Provides In-house Expertise and Support

With over 40 years of experience in wet bench technology and extensive in-house expertise in manufacturing operations, Modutek can help customers choose the right level of automation for their semiconductor fabrication line. Modutek offers free consultations and can discuss how different levels of automation and robotics usage can impact fabrication line performance. In general, the right level of automation for a semiconductor fabrication facility is one that improves process control and optimization and delivers long-term cost savings while improving output. Contact Modutek for a free consultation to discuss the details of your manufacturing equipment requirements.

Designing Chemical Delivery Systems to Meet Facility Requirements

Because semiconductor manufacturing facilities use a variety of chemicals to clean, etch and process silicon wafers, chemical delivery systems are critical for ensuring that operations run smoothly. Chemical handling equipment delivers or collects the required chemicals for the safe disposal of the chemical waste. Effective chemical delivery systems remove concerns about the availability and correct mixture of process chemicals and allow operators to focus on issues directly affecting silicon wafer fabrication, such as wafer cleaning, etch rates, and particle contamination. When chemical delivery systems exactly meet facility requirements, a focus on the fabrication processes lets operators optimize production and helps improve output.

Adapting Receiving and Storage of Chemicals to Facility Requirements

Chemical delivery depends on how many different chemicals a facility requires and the volume of the chemicals used. Chemical characteristics such as toxicity also have to be considered. For facilities using a variety of chemicals in varying quantities, a special area may be needed to centralize reception and storage functions.

For small volumes of chemicals, a standard drum located near the process may be the most convenient. For large volumes, receiving and storing chemical totes monitored with a load cell to track chemical use could be the best solution. For dangerous chemicals, containment of possible leaks and special safety measures may be required to ensure compliance with environmental and safety regulations. A competent manufacturer of chemical delivery and storage systems can evaluate these factors and make corresponding recommendations.

Ensuring Timely and Reliable Delivery of Chemicals to the Process

The key function of chemical delivery systems is to ensure that the required chemicals are provided in precise amounts as needed for the process. Silicon wafer fabrication steps clean and etch wafers with mixtures of chemicals that have to be delivered to process tanks. Each step requires precise quantities of chemicals delivered in sequence and at timed or process-dependent intervals. Each facility has different process steps and different chemical delivery requirements. A well-designed chemical delivery system will reliably provide exactly the right chemical in the specified volume at the correct time.

Collecting and Disposing of Used Chemicals Safely

Once a process step is complete, the chemical mixture that remains is often still chemically active, toxic and dangerous. The wafers will have been removed from the chemical bath and the used chemicals need to be safely treated or collected and disposed. For example, acids used in wafer etching are hazardous for operators, harmful for the environment and even the vapors may be dangerous.

Disposal of chemical waste has to be in accordance with local safety and environmental regulations. The chemical system can either drain the chemical waste and send it to an on-site chemical neutralization system for treatment, or to storage in a chemical collection container. Used chemicals in chemical collection containers can be picked up by service providers that specialize in chemical disposal. In either case, the chemical handling has to be carried out safely while containing any leaks or spills.

Modutek’s Expertise with Chemical Delivery Systems

Modutek has extensive experience designing and building customized chemical delivery systems. With in-house expertise in designing and supplying a full line of chemical handling equipment and systems, Modutek can evaluate a facility’s chemical delivery needs and make corresponding recommendations. If you need guidance on selecting the right chemical handling equipment and systems for your facility, contact Modutek for a free consultation.

Free Standing IPA Vapor Dryer Improves Wafer Processing

When a series of semiconductor manufacturing steps are complete, the silicon wafers have to be rinsed and dried. At this stage in the fabrication process, the surface of the silicon wafer has to be as free as possible from particle contamination wafer and free from water marks caused by the water evaporating on the wafer. The free-standing IPA vapor dryer uses IPA (isopropyl alcohol) to eliminate water marks and reduce the particle count. IPA vapor drying, also known as Marangoni drying, delivers clean wafers for improved processing by increasing yield and output quality.

IPA Vapor Drying Works by Removing Water from the Wafer Surface

In IPA vapor drying, the silicon wafers are first rinsed with deionized water. IPA vapor is then introduced into the closed drying chamber. Where the IPA interfaces with the deionized water on the wafer surface, the lower surface tension of the IPA causes the water to flow off the wafer surface, taking impurities with it and leaving the wafer clean and dry.

This method of drying silicon wafers is a good alternative to spin drying because it does not stress the wafers mechanically and leaves no water marks. Rinsing and drying takes place in a single unit, avoiding a transfer of the wafers and eliminating a source of contamination. The IPA drying method can be cost-effective, especially if the consumption of IPA is kept low. IPA drying gives excellent results in terms of low particle counts and wafer cleanliness.

Modutek’s IPA Vapor Dryer Provides Superior Performance with Low Operating Costs

Modutek’s free-standing IPA vapor dryer is made from polypropylene with Teflon fittings and pipes. Its 30-inch wide space-saving design can easily be integrated into a wet processing equipment production line or used independently to rinse and dry wafers. The IPA vapor is introduced at the top of the enclosure from a standard one-gallon bottle located at deck level in the exhaust compartment for easy bottle changes. From the top, the vapor is distributed evenly throughout the chamber. Drying time is typically about ten to fifteen minutes.

In addition to the basic drying function, Modutek’s design also includes de-ionized water degassing, N2 head case purging, and hot N2 drying. The station is operated from a touch screen with an intuitive graphic user interface that allows the programming of multiple operating sequences.

Features include a continuous flow deionized water manifold, an automatic lid that opens with a foot switch, and removable PVC side shields. Options include a manual lid, a quick dump feature, data logging, and the use of ozone to eliminate remaining organic impurities. For special applications, Modutek can adapt the dryer design to meet customer requirements.

Advantages and Benefits of the Free Standing IPA Vapor Dryer

With vapor generation inside the standard bottle and vapor introduction from the top of the enclosure, Modutek’s IPA vapor dryer has a very low IPA consumption and low operating costs. The included features and options along with possible customization allow for flexible operation and make the dryer an ideal addition to a semiconductor fabrication line. Excellent rinsing and drying performance, rapid operation, and programmable cycles deliver superior results and higher throughput. Clean wafers with low particle counts can reduce rejects and improve yield. The flexible design makes the station suitable for production lines, batch processing, and individual prototyping or test products.

Based on the company’s extensive experience in the design and building of semiconductor manufacturing equipment, Modutek can advise customers on the type of system they need and can deliver equipment from its complete line of wet process stations. Modutek designs and builds all its own products in-house and has the expertise to ensure IPA vapor dryers and other equipment meets the needs of customers and performs as required. Contact Modutek for a free quote or consultation to discuss your specific requirements.

How Precision Parts Cleaning is Supported with Automation

Precision cleaning of industrial parts can be time-consuming and expensive. Manual brushing and scraping are labor-intensive and can result in injuries to the workers or damage to the parts. Handling heavy parts from manufacturing equipment is often difficult, especially when they have to be placed in a chemical bath. The chemicals themselves are expensive and spills or errors in mixing can be dangerous.

When precision parts cleaning is automated, chemical use is clearly defined and waste is reduced. The automated system handles the parts so worker safety is improved. Workers can carry out other tasks while the automated system carries out the cleaning. In this way, automation can save time, reduce precision cleaning costs and improve cleaning performance.

Fully Automated Precision Cleaning Results in Consistent Cleaning Performance

The automated precision parts cleaning system is made up of the cleaning station, robotics, and automation. The cleaning station includes the cleaning tank, an enclosure, and the piping for the cleaning chemicals and solutions while the robotics handles the parts to be cleaned. The automation system runs the cleaning process and has an operator interface used to program the system and to observe the cleaning process.

Once the automation system is programmed for a cleaning application, the operator can place the parts to be cleaned in a basket. The robotics transfers the basket to the cleaning station and positions it for cleaning. The automation system goes through the programmed cleaning cycle, whether it involves di-water cleaning, megasonic cleaning, immersion, or other cleaning processes, adding chemicals and draining the baths as needed. Once the cleaning cycle is complete, the robotics removes the basket from the cleaning station and presents the clean parts to the operator.

Fully automated precision cleaning is especially valuable when the same or similar parts are cleaned repeatedly or when manufactured parts have to be cleaned before shipment. Sample parts can be cleaned and checked to see whether the cleaning performance is adequate. Once the automatic cleaning is satisfactory, the program can be run repeatedly to give consistent results. A series of parts are cleaned exactly the same way and present the same level of cleanliness.

The Modutek Automated Precision Cleaning Stations Support Customer Requirements

Modutek offers a fully automated solution for precision industrial cleaning of small, mid-sized, and large parts, usually made of metal or glass that typically weigh up to 45 pounds. A 2 X 2-foot basket can hold one or more parts and has a payload of 100 pounds. Baskets with payloads of 150 pounds or more can also be supported. The basket takes the parts to be cleaned and places them in position inside the cleaning station. Once started, the cleaning process runs without operator intervention until the cleaning cycle is complete and the basket brings out the clean parts for operator pickup.

A touch screen can show the progress of the cleaning process and the operation of the station. The touch screen can also be used for configuring the automated cycles and for operating the cleaning station. Normally, once the cleaning cycle has been programmed, the station will run until the clean parts are ready to be taken away. Modutek’s precision cleaning stations are ideal for precise cleaning of industrial parts that are not easily manipulated for manual cleaning. The automation and the robotic part handling equipment reduce the possibility of operator error and worker injury. Modutek’s industrial parts cleaning equipment can be designed and built to meet your specific application requirements.

Modutek is a leading semiconductor equipment manufacturer, that has in-house experience and expertise in designing equipment for wet processing and silicon wafer cleaning applications. The company can advise customers on the type of automated cleaning systems needed to meet manufacturing requirements. Contact Modutek for a free consultation to discuss the specific cleaning needed for your industrial parts.

Innovative Table Top Units that Support Chemical Wet Processing

Research, proof of concept, or prototyping often require the production of single silicon semiconductors or a small number of functional units. Using a semiconductor manufacturing line for this purpose is expensive and lacks flexibility. Wet process manufacturing can be scaled back to reduce equipment size without losing functionality. Modutek has developed table top units that can carry out the most important silicon wet etching functions to produce small volumes of semiconductor products quickly and efficiently.

Modutek’s Table Top Units Support the Most Common Kinds of Chemical Wet Processing

The table top chemical wet processing units that are compact, self-supporting systems made up of a Teflon tank or stainless-steel solvent tank and a control box. The tanks are available as ambient or temperature-controlled models and can be static baths or recirculating baths with a filter. They support KOH etch, buffered oxide etch (BOE), solvent resist strip and they can be fitted out for other types of wet processing.

The temperature-controlled tanks feature fast temperature rise, uniform heating, and accurate temperature maintenance. Tanks have an all-Teflon fluid path, level, and temperature alarms, and a drain interlock. Their size makes them ideal for small batches, test units, or multiple versions of a basic design.

KOH Etch Using Modutek Table Top Units

KOH etching is widely used because it is relatively safe and easy to control. The concentration of the potassium hydroxide and the temperature of the bath are the key variables for determining the etch rate. Once the concentration is set, the table top units can control the temperature to get the desired etch rate. The rapid temperature rise speeds up the overall process and improves efficiency. The precision of the temperature control ensures that the etched cavities in the silicon wafer are exactly as required and provide for excellent repeatability.

The table top units are designed to minimize impurities and deliver high-quality output. Design changes in semiconductor structure are reliably carried out while the basic structures of the original design remain identical from one process run to the next.

The Table Top Units Can Handle Solvent Resist Strip

Solvents used in semiconductor manufacturing can remove resist, oils, and organic contaminants from silicon wafers in preparation for further processing steps. Acetone, isopropyl alcohol (IPA) and ethylene diproxitol (EDP) are solvents commonly used to clean wafers, remove photoresists, and in pattern transfers for the creation of microscopic structures on the wafer. The solvents are inflammable and require special safety measures to reduce the risk of fire and explosion, and they have to be disposed of safely. Modutek’s table top system supplies all of this in an easy-to-install design package.

Sub Ambient Buffered Oxide Etch (BOE) with Table Top Units

The BOE process is used to etch thin layers of silicon dioxide or silicon nitride with hydrofluoric acid and a buffer. For sub ambient BOE, the table top units are fitted with a chiller/heater that permits an operation in the 10-to-60-degree centigrade range. The sub ambient filtered etch bath reduces acid consumption and delivers highly efficient filtration. The table top units feature a safe and reliable operation at a comparatively low cost.

Modutek Can Design Custom Units for Special Applications

As a leading manufacturer of silicon wet etching equipment, Modutek designs builds and tests their own products in-house. Modutek works closely with customers to develop innovative approaches that solve industry problems. Contact Modutek for a free quote or consultation for specialized equipment that meets your wet processing requirements.

Why Chemical Collection Carts are Needed for Chemical Handling

When high-volume chemical delivery systems are not needed because of small production volumes, chemical collection carts can provide safe chemical handling. Also known as chemical delivery carts or chemical pump carts depending on their role, these chemical carts can safely deliver chemicals to the process and remove them for disposal.

Safe handling of aggressive chemicals is especially important for small facilities that can benefit from the use of chemical collection carts. Labs, research centers and universities often have limited space and lack chemical treatment capability. Using chemical collection carts for the removal of used chemicals and safely delivering them to a specialized chemical treatment provider means small production sites don’t have to worry about adhering to disposal regulations.

Modutek’s Chemical Cart Characteristics and Features

Modutek’s chemical carts are designed for safety, ease of use, and flexibility. The incorporated on-cart holding tank can vary from 5 to 25 gallons and the carts can hold a 55-gallon drum in an optional configuration. The tanks are mounted on swivel casters with brakes and measure 18 inches wide, 36 inches long, and approximately 42 inches high.

With a three-eighths inch pneumatic pump and all-pneumatic operation, no electrical connection is required. Construction is white polypropylene with an all-Teflon fluid path and a stainless-steel option is available for solvent applications. The carts feature independent suction and discharge tubes and there is a high-level sensor with a pump interlock in the holding tank.

Operation of the carts for the dispensing of solvents, acids, or bases and the removal of waste chemicals is straightforward. The suction tube transfers chemicals from an external tank to the holding tank while the discharge tube drains holding tank chemicals and transfers them to an external container. A single pump cart can be used for multiple applications.

Chemical Collection Carts Are a Safe Way of Handling Chemicals

While still requiring manual operation, chemical pump carts can reduce the possibility of spills and accidents. With the use of carts, the transfer of chemicals between containers takes place in a controlled and structured fashion. Aggressive chemicals can be kept at a distance from the operators and workplace safety increases.

In normal use, the pump cart can be rolled up to the chemical processing station and can transfer the required chemicals. For chemical removal and disposal, for example, the suction tube of the cart can transfer the waste chemicals from the process tank to the cart holding tank. The cart can then be rolled out for chemical disposal.

Facilities that use chemicals for their production lines may have their own neutralization and disposal systems, but smaller facilities including universities and research labs often outsource chemical neutralization and disposal to specialized service providers. If the manufacturing facility neutralizes its own waste chemicals, the pump cart can transfer the collected waste from the holding tank into the neutralizing and disposal system. If an external service provider is used for chemical disposal, Modutek’s carts make it easy to ship the containers holding the waste.

The holding tanks on Modutek’s carts feature double containment for extra safety. If the waste chemicals are not neutralized on site, they are stored in a Department of Transport (DOT) approved container for pickup by the specialized chemical processing company. In this case, no in-house chemical neutralization processing is required.

Modutek designs and builds its own systems and equipment in-house. This means that the company can easily customize chemical collection carts to meet special customer requirements. Modutek works closely with customers to identify what they need and works and develops systems and equipment to meet their specific requirements. Contact Modutek for a free consultation and quote on equipment needed to support your chemical processing and disposal needs.

Improving Silicon Wafer Processing with High Temperature Quartz Tanks

Because silicon wafer processing uses acids and bases, the process requires tanks that are impervious to aggressive chemicals. Quartz tanks are stable and do not take part in wet process chemical reactions, even at the high temperatures reached during some of the process steps. Modutek’s quartz tanks use pure flame-polished quartz to reduce impurities that might contaminate the chemical reactions. To keep the temperature at the setpoint, Modutek has added precise temperature controls. As a result, Modutek’s quartz tanks represent an ideal way to implement wet process wafer fabrication steps.

Quartz Tanks Improve Output by Reducing Contamination

The output quality of wet process semiconductor manufacturing is directly affected by contamination during silicon wafer processing. When microscopic particles adhere to wafer surfaces, wafer etching can be disrupted and the semiconductors produced by the manufacturer can be defective or of poor quality. A major concern during silicon wafer processing is the reduction of the particle count on the surface of each wafer.

The high-purity semiconductor grade quartz used in Modutek’s tanks is made up of a crystal lattice containing tightly-held atoms of silicon and oxygen. These elements remain locked in the lattice while the wet process chemical reactions of wafer cleaning, stripping, and etching take place. This ensures that the quartz tanks act as neutral containers and don’t add contaminants or particles to the wafers.

After processing a wafer through one of the many steps of semiconductor manufacturing, a wafer has to be clean and almost completely free of particles. When Modutek’s quartz tanks are used for processing, potential particle contamination from the tanks is significantly reduced. The tanks are based on over 30+ years of bath design and feature a seamless, sloped flange construction. This is especially important for semiconductor manufacturing as industry trends have been moving toward tighter packing and reduced structure sizes. This means even a single small particle can block an etched path or result in a defective structure. By reducing particle counts, Modutek’s quartz tanks improve manufacturing results.

Quartz Tanks with Tight Temperature Control for Improved Etching Precision

The exact shape and location of etched structures in the silicon are critical for the correct functioning of the final semiconductor device. Etching speed determines the shapes of the etched structures in the silicon and the speed is controlled by the chemical concentration and the reaction temperature. The chemical concentration is set at the beginning of the process steps for most of the processes, but the temperature can be used to control the etching speed.

Modutek’s quartz tanks are designed to keep the temperature at exactly the setpoints required for the process and to deliver the anticipated etch speed. The bath temperature can be controlled precisely up to 180 degrees centigrade and the tanks feature a quick temperature rise of up to 2 degrees centigrade per minute with an accuracy of plus/minus 1-degree centigrade.

Heating is even and the fast rate of temperature increase improves throughput. The high accuracy allows precise prediction of etching distances and reliable repeatability of the process when different batches are manufactured. Tank design provides high reliability and safety with a view to a low total cost of ownership.

Using the Right Quartz Tanks Improves Processing and Overall Output Quality

As a leading semiconductor equipment manufacturer, Modutek works with customers to design processing equipment that will help them meet manufacturing requirements. Modutek’s recirculating and constant temperature quartz tanks improve silicon wafer processing by reducing contaminating particle counts and ensuring precise control of etching. The reduced particle counts and the reliable production of required etched shapes reduce defects and rejects in manufactured devices. Contact Modutek for a free consultation and quote on selecting the right equipment to support your manufacturing requirements.

How Megasonic Cleaning Improves Silicon Wafer Manufacturing

When silicon wafers are cleaned between manufacturing steps, it is critical to remove all contamination from the wafer surfaces. The remaining traces of process chemicals or microscopic particles can disrupt the etching process and result in defective or low-quality semiconductor devices.

Megasonic cleaning uses high-frequency sound waves in the cleaning tank to remove contaminants and particles from the silicon wafers. The technology can save time and money because it works quickly and does not require expensive chemicals. Silicon wafers cleaned with Megasonic cleaning are completely clean with a reduced particle count. As a result, the technology can improve the operation of semiconductor manufacturing lines for semiconductor fabricators and research labs.

Megasonic Cleaning Reduces the Use of Toxic Chemicals

The cleaning of silicon wafers after the completion of each semiconductor manufacturing step is accomplished by soaking the wafers in mixtures of chemicals including hydrochloric acid or sulfuric acid. In addition to the cost of the chemicals themselves, there are ongoing costs related to the storage, delivery, and disposal of these chemicals. The possibility of leaks and the disposal of the waste chemicals represent environmental hazards that are continuously being mitigated with tighter regulations. Reducing the use of aggressive chemicals can save money beyond their direct cost and can improve the environmental footprint of the semiconductor manufacturing facility.

With Megasonic cleaning, a frequency generator produces an electric signal in the MHz range that is transmitted to a transducer. The transducer that is immersed in the cleaning solution converts the signal to sound waves in the cleaning tank. The sound waves create microscopic cavitation bubbles that deliver a gentle scrubbing action against the surface of the silicon wafer. The cleaning intensity is strong enough to dislodge impurities and contaminants but will not damage the wafer surface or the microscopic structures that have been etched into it.

When Megasonic cleaning is used to replace some of the traditional cleaning steps, the use of chemicals is reduced. Megasonic cleaning uses plain water or water with the addition of mild detergents. The cost benefits and reduced environmental impact can be substantial, and the areas where Megasonic cleaning is used will have increased worker safety and reduced chemical exposure.

Megasonic Cleaning Can Deliver Improved Cleaning Performance

While acid baths work well for cleaning general contaminants from silicon wafer surfaces, ensuring low particle counts can be challenging. Contaminating particles can block etching and cause defects in the final semiconductor devices. As functions become more and more closely packed on the wafer and microscopic structures become smaller, a single particle can affect the etched shapes and current paths. A key factor for improving output quality and reducing defects is reducing particle counts to a minimum.

Microscopic particles can be difficult to remove from the surface of silicon wafers because they often develop a static charge that allows them to cling to the wafer. Chemicals can dissolve the substances that make the particle adhere to the wafer surface but the static charge often remains as an additional bond. With Megasonic cleaning, very small cavitation bubbles form and collapse in tune with the sound wave frequency in the MHz range. When a bubble collapses near the wafer surface, it emits a powerful jet that dislodges any particle still clinging to the surface. Wafers that have been cleaned with Megasonic cleaning systems have a lower particle count as well as a high degree of cleanliness.

Modutek Can Help with Megasonic Cleaning Integration

As a leading manufacturer of wet process semiconductor manufacturing equipment, Modutek can help customers integrate Megasonic cleaning into their wafer cleaning process. Modutek offers free consultation and can show customers how to realize the benefits of lower costs, better output quality, and improved yields.