Specialized Wafer Etching for Critical Wet Processing Applications

The success of the wet process application depends on selecting wet bench processes designed for the tasks at hand. Specialized equipment can support different etching and cleaning processes and can be used to make sure that the process selected can fulfill specific application requirements.

Depending on the etching or the cleaning task to be performed, specific wafer etching processes are needed. For example, the fabrication of solar cells has different requirements compared to the requirements for the creation of microscopic structures for a processor. Here are the following major process characteristics which can impact wafer manufacturing:

1)     Low particle count – these characteristics are especially critical for the smallest structures. A high particle count can cause defects in micro structures, which result in higher failure rates during final testing.

2)     Etching speed – If the goal is to remove substance as fast as possible, high-speed etching can be used, but with this process, precision can be compromised.

3)     Selectivity – for highly selective processes, the substrate material is not affected by the etchant while the material to be removed is etched rapidly.

4)     Precise control – this characteristic becomes more critical as the dimensions of the micro-structures decrease and the packing of components becomes denser.

5)     Undercutting – It compromises control precision but can be minimized or eliminated with anisotropic etching by selecting the proper process and the orientation of the silicon crystal planes.

Choosing the right process to deliver the etching characteristics required will have a high impact on wafer etching process line performance. Key performance indicators that include product rejection rates, throughput, downtimes and operating costs can vary greatly, depending on the best match of the process to application.

Modutek's wet process stations are specialized for different processes and also guarantee safe and reliable operations. The company offers a complete line of wet process stations and can deliver solutions for general etching and cleaning, as well as for specialized applications. Modutek's equipment supports several processes, including:

• Piranha etch – removes organic material from substrates and is often used to remove photoresist from silicon wafers. Modutek can determine whether piranha etch is a good fit for a specific application.
• KOH etching process – the etch rate is controlled by changing the temperature of the KOH etching (potassium hydroxide). Modutek supports this process with baths that provide tight temperature control.
• Buffered Oxide Etch (BOE) – is used primarily to etch silicon dioxide and silicon nitride. Modutek supports this process with its sub-ambient filtered baths.
• Ozone resist strip – it cleans organic residue while reducing particle count. Modutek supports this with the ozone strip process which does not use chemicals

For more details about this topic, read the complete article “Specialized Wafer Etching for Critical Wet Processing Applications”. If you would like to set up a free consultation to discuss any questions you may have, contact Modutek at 866-803-1533 or email to Modutek@modutek.com.

How Quartz Tanks Improve Wafer Manufacturing

Chemicals used in wet process wafer manufacturing need to be contained in process tanks that can resist etching, corrosion and remain inert. In some applications, a process may require heating, filtration or the regular addition of chemicals. Quartz tanks are made from semiconductor grade flame-polished quartz and are impervious to the acids and bases used in wafer processing. They minimize contamination of wafers from particles and can be supplied in heated and re-circulating models.

Wet bench processing of silicon wafers consists of fabrication steps such as etching and diffusion with cleaning required in between the steps. The wafers are “masked” to etch specific parts of the wafer to confine diffusion to certain target areas. Once each process step is done, the masking material must be cleaned off.

Cleaning the wafers completely without contamination is crucial. When the wafer is not clean and still has contaminants, even a single particle can result in a badly formed structure or conductor. When such malformations are incorporated into the final product, it can result in defective or lower-quality semiconductor components.

Modutek offers specialized quartz tanks that are made from semiconductor grade flame-polished quartz and are impervious to the acids and bases used in wafer processing. Quartz tank controls allow operators to program reproducible process environments and make sure temperatures and chemical concentrations are consistent. Heating, chemical spiking, and filtration are the three important areas for which specialized control systems are useful.

Heating – Modutek's high-temperature re-circulating baths and constant temperature tanks heat up rapidly with a temperature rise of up to two degrees centigrade per minute. Quick heating helps improve throughput and accurate temperature control helps ensure high-quality results.

Chemical spiking – Periodic spiking restores the chemical concentration of the chemicals to the desired effect. Modutek has developed an innovative “bleed and feed” spiking method for the sulfuric acid and hydrogen peroxide process.

Filtration – Modutek's quartz tanks can also reduce particle counts and wafer contamination. The quartz re-circulating tank can filter out particles down to 0.2 microns, improving output quality and reducing component failure rates.

The complete article, “How Quartz Tanks Improve Wafer Manufacturing” explains more details. If you have questions and would like to set up a free consultation, contact Modutek at modutek@modutek.com or call 866-803-1533.

How Megasonic Cleaning Improves Silicon Wafer Manufacturing Results

Semiconductor components that include processors, switches and memory chips have become so miniaturized, that even sub-micron foreign particles can block the formation of a conducting path or other key structural components. That is why removal of sub-micron particles during the manufacturing process is crucial to avoid defective products. These particles are usually removed by traditional cleaning and rinsing using aggressive chemicals. However, megasonic cleaning is the better alternative option in cleaning silicon wafers because it can remove even the tiniest particles.

Megasonic cleaning uses megasonic sound waves to remove contamination from surfaces of parts being cleaned. The sound waves in the cleaning solution create microscopic bubbles in the wave pressure troughs and collapse them in the wave peaks. When a bubble collapses, it discharges a tiny but powerful and energetic jet of cleaning solution that dislodges contaminants and particles from part surfaces. Modutek has partnered with Kaijo Shibuya Corporation, a world leader in Megasonic and ultrasonic cleaning systems, to create a line of Megasonic cleaning equipment suitable for use in semiconductor manufacturing.

Megasonic cleaning uses a wide range of frequencies. The right selection of frequencies is the key to optimum cleaning performance. Lower frequencies are used for less fragile devices, while higher frequencies are suitable for gentle cleaning of the more delicate parts or parts with soft surfaces.

And because semiconductor components often include very delicate structures and soft layers of deposits on the surface, only the highest frequencies deliver gentle cleaning to avoid damage and pitting to these fragile structures.

Modutek’s Megasonic cleaning system can clean at frequencies between 200 kHz and 2 MHz but generally operates at 950 kHz. The system delivers up to 1200 W of cleaning power and can operate with bath temperatures of up to 140 degrees centigrade. The system offer superior performance and can removal rate for particles down to 0.1 microns which improve semiconductor component yields, reduces the number of defective components and improves product quality.

For more details read the complete article “How Megasonic Cleaning Improves Silicon Wafer Manufacturing Results”. If you have questions after reading the article, or would like to set up a free consultation, contact Modutek at modutek@modutek.com or call 866-803-1533.

Customized Table Top Chemical Process Tanks

Table top chemical process tanks are more ideal for smaller operations and specialized applications that require semiconductor fabrication capabilities.

Research labs, universities and start-up companies can use table top chemical process tanks to produce single parts or low-volume components for either proof of concept or prototype testing. Small chemical process tanks provide the capability to fabricate such products in a customized unit designed for the specialized applications.

Table top chemical process tanks for specialized output are heavily customized to reflect their unique purposes. Tank size, chemicals used, controls, heating and circulation are all adapted to the particular use. Since Modutek designs and builds all of its wet bench equipment in-house, the company is ideally suited to provide the customization required for this special application.

Features and benefits of the Modutek Table Top Systems:

• Installation – Mobile tanks with customized shapes and sizes.
• Circulation – Tanks can be static or fitted with overflow circulation and filtration.
• Heating – Tanks are ambient temperature or temperature controlled. For heated tanks, the operating temperature is 30 to 100 degrees centigrade.
• Process – The tanks are usually Teflon tanks for KOH and related wet purposes.
• Wafer Holders – The systems usually come with standard carriers sizes for single or double capacity, as well as custom-made sizes.
• Controls – There are process controllers available to handle temperature and timing.

Modutek can assemble customized table top chemical process tanks with the required features exactly as specified by customer to meet their requirements. Benefits include reliable and safe operation, consistent process variables and repeatable outputs and results. For more details read the complete article titled “Customized Table Top Chemical Process Tanks”. Contact Modutek for a free quote or consultation to discuss your specific chemical process application requirements.

Selecting the Right Acid Neutralization System for Your Application

An acid neutralization system treats the discharge from the semiconductor wet process fabrication facilities, as well as other industrial processes, to make the liquids environmentally safe for disposal.

The right system for an application will add alkaline chemicals to the acidic solution and increase the pH close to the neutral reading of 7, while recording process data to ensure regulatory compliance. If the acid is untreated, releasing it would be environmentally hazardous and pollute waterways. Governments have imposed regulations on the procedures required to dispose of industrial waste.

 An acid neutralization system treats and measures the acidity of wastewater as it exits the production line. Depending on the process, a suitable neutralizing chemical is added to reduce the acidity. The sensors verify that the pH level of the wastewater has been reduced due to neutralization. That pH level should be in compliance with the applicable government regulations before the liquid can be released.

 Depending on the type of operation, an acid neutralization system can be selected in either continuous flow or in batches:

 1) Continuous flow neutralization
 This applies to the continuous flow acid neutralization systems which have a continuous addition of neutralizing chemicals. There is only a slight variation that is easily controlled and monitored. The flow can be from a few gallons to several hundred gallons per minute. Discharges and their characteristics are recorded on a digital chart recorder.

 2) Batch neutralization
 In this type of neutralization system, the batches of waste chemicals often need extensive treatment and may require different neutralizing chemicals to meet the allowed discharge pH levels. The system takes the pH level reading and then adds the necessary chemicals to verify the correct pH level has been reached.

 Modutek’s acid neutralization systems are fully automated and are available in batch neutralization or continuous flow designs. The compact design allows these systems to fit into available space and can be customized for specific applications.

For more details read the complete article, “Selecting the Right Acid Neutralization System for Your Application”. Contact Modutek at 866–803–1522 or email Modutek@modutek.com to schedule a free consultation to discuss your specific requirements or get a free quote.

5 Important Things to Know When Buying Wet Bench Stations

Because of the complicated nature of semiconductor manufacturing, wet benches need to be customized to meet specific requirements for a specific application.

Before focusing on the process-specific requirements, there are general questions that should be answered. They include the level of automation, whether stainless steel solvent stations are required, whether a chemical delivery system is needed and whether any special options for rinsing and drying would be beneficial. Following this structured approach helps with selecting the best wet process station configuration and with integrating special equipment within the wet bench station.

1) Automated Wet Bench Stations
Modutek's line of wet bench stations can be manual, semi-automatic or fully automated. You get the most benefits from using fully automated stations since they can run batches without operator intervention and provide excellent repeatability if the same product is manufactured multiple times. The use of Modutek's proprietary software will help increase throughput and yield.

2) Stainless Steel Solvent Stations
Modutek's stainless steel solvent stations are available in the manual, semi-automatic and fully automated stations as well as in dry-to-dry configurations. Solvent stations are designed to satisfy fire safety standards that are needed in solvent applications.

3) Chemical Delivery System
Modutek's chemical delivery systems help avoid spills and make tracking of chemical neutralization and disposal easier. The company can also customize the system's design to exactly meet the needs of a customer’s application.

4) Rinsing and Drying
When an etching or cleaning process step is complete, the wafers must be rinsed and dried without leaving any contaminants. Modutek's IPA dryer combines rinsing and drying in one station while the quick dump rinser improves the process efficiently.

5) Special Etching or Cleaning Equipment
Some semiconductor fabrication and research facilities may require specialized wet bench equipment for specific etching or cleaning process steps. For this reason, Modutek can incorporate specialized equipment such as the Vacuum Metal Etcher which is designed to etch aluminum layers with high precision and remove hydrogen bubbles when they are created.

For more details read the complete article “5 Important Things to Know When Buying Wet Bench Stations”. Contact Modutek by email at Modutek@modutek.com or call 866-803-1533 to schedule a free consultation to discuss your needs or get a free quote.

How Modutek’s Fully Automated Wafer Fabrication Equipment Improves Process Control

Particle contamination has a challenging problem when the structures and conductors on the silicon wafers are small or tightly packed. On the smallest microscopic structures, a single particle can block a conductor, distort a structure or affect diffusion. To address this issue Modutek's product line includes fully automated wafer fabrication equipment and wet bench stations. The company develops its own software for the equipment in-house and assembles all its wet stations in its San Jose facility.

Modutek makes extensive use of software control and robotics to ensure excellent process control and high-quality output. These can optimize the automation for the best possible performance and customized equipment can be used to meet specific application requirements.

The full range of benefits that Modutek's fully automated stations include the following:

• Reduced chemical usage
• Improved etch rates
• Higher yields
• Better throughput
• Excellent repeatability
• Ability to handle both acid and solvent applications
• Ability to work with standard wafer carrier sizes and custom sizes up to 30” x 60”
• Extensive tracking of process variables
• Highest output quality

The SECS (SEMI Equipment Communications Standard) and GEM (Generic Equipment Model) protocol standards both specify how automated semiconductor fabrication equipment can communicate with a host computer. These standards are developed by the Semiconductor Equipment and Materials International organization, and they define interfaces, messaging and communication capabilities.

Modutek's fully automated stations support this protocol and can supply a variety of data to the hosts while receiving remote commands to start or stop a process and to choose stored recipes or programs. Using in-house experience in wet processing semiconductor manufacturing Modutek can customize their wafer fabrication equipment to meet the specific needs of the customer’s application.

Read the complete article “How Fully Automated Wafer Fabrication Equipment Improves Process Control” which goes into greater detail. Contact Modutek at 866-803-1533 or by email Modutek@modutek.com for a free consultation to discuss your specific process requirements.

How Fully Automated Wafer Fabrication Equipment Improves Process Control

Precise process control and the elimination of particle contamination have become more important as the microscopic structures etched on silicon wafers have also become more intricate and densely packed. The accuracy of chemical dosages and the timing of the steps must be consistent and handling of wafers must be kept to a minimum. For this reason, fully automated wafer fabrication equipment is used to ensure that such conditions for the production of semiconductor components are achieved.

There is manual and semi-automatic wafer processing equipment which rely on operators to mix chemicals and transfer wafers. However, errors and inconsistencies in execution can result in defective or low-quality products and production downtime and reduced throughput. Productivity also suffers. The semiconductor manufacturing facility's general operations will become less efficient and less profitable.

Software is the key to automation. When software is used to control the wafer fabrication equipment, it eliminates the variability found in manual operation and inconsistent documentation. Using software to run fully automated stations can provide the following benefits:

• It ensures and maintains exact chemical ratios with each batch
• Precise and repeatable process steps
• Process variables can be easily optimized by programming small changes in the software
• Accurate chemical dosages result in reduced waste and lowered chemical use
• Chemical neutralization and disposal are reliable and easily documented
• Worker safety is enhanced as operators are less exposed to toxic chemicals

The benefits listed above come from programming automatic controls which manage the cleaning and etching of the silicon wafers. The software will calculate how much of each chemical is needed for a particular process step. It controls the adding of the chemicals to the process tank, times the process step, drains the chemicals and neutralizes all the waste chemicals. Once the variables in the software are optimized, the software will run the optimized process the same way every time. This allows the results to be predictable and consistent.

The complete article “How Fully Automated Wafer Fabrication Equipment Improves Process Control” provides more details. Contact Modutek at 866-803-1533 or email at Modutek@modutek.com more information or would like a free consultation to discuss your specific requirements.

Isotropic and Anisotropic Silicon Wet Etching Processes

The silicon wet etching of monocrystalline wafers produces microscopic structures that are used in mechanical devices and semiconductor parts. When the silicon wafer is immersed in a chemical bath, only the exposed parts of the silicon wafer are subject to etching. Its other parts, that are not to be etched, are protected by a mask.

Find additional details about isotropic and anisotropic silicon wet etching in these documents:

•  University of Maryland - Silicon Wet Isotropic and Anisotropic Etching

•  University of California at Irvine - Anisotropic Silicon Etch Using KOH

In isotropic etching, the isotropic etchant etches the silicon wafer equally in all directions. This means that the wafer is etched downward and sideways under the mask, resulting in a cavity which usually consists of rounded corners and edges which are bigger than the opening in the mask.

In anisotropic etching, the anisotropic etchant such as potassium hydroxide (KOH), etches at varying speeds in different directions. This means that the etch rate in the downward direction is faster than the etch rate in the sideways direction. This leaves to cavities with straight sides and less undercutting of the mask.

  

The silicon wafer mask defines where etching can take place, however, the depth of the etched cavity and its shape can be made by selecting the right etchant and controlling the etching rate. Isotropic etching is often used to achieve larger features in the initial stages of the silicon wafer processing, while anisotropic etching is used to produce straight-edged microstructures in the final stages.

The etch rate is also a significant factor. It depends on the concentration of the etchant and the etching solution temperature. Once the etch rate is determined at a certain temperature, the masked silicon wafer is immersed into the etchant. The etching should be long enough to produce the required cavity size. The subsequent wafers will undergo the same process for reproducible results.

Silicon wet etching equipment that includes Modutek’s Teflon tanks can be used to support both isotropic and anisotropic processes. For processes that are temperature-dependant, the tank temperature controller provides rapid and accurate heating control.

The complete article “Isotropic and Anisotropic Silicon Wet Etching Processes”, explains the processes in further detail. If you have questions about selecting the right equipment for your silicon wet etching process, contact Modutek at 866-803-1533 or email Modutek@modutek.com. 

Safely Controlling the Silicon Nitride Etching Process

Silicon nitride etch removes silicon nitride from silicon wafers during the fabrication process of semiconductor components. It consists of a solution of phosphoric acid in water which etches silicon nitride. When the temperature of the solution and the concentration of phosphoric are kept constant, the etching will be carried out rapidly and consistently.

The silicon nitride wet etching process uses silicon nitride as a mask to produce the micro-structures and connections in semiconductor devices. In most etching applications the etch rate can vary by changing the temperature or chemical concentration, but the ideal conditions for a successful etch rate consist of a boiling point and a concentration of 85% phosphoric acid in a de-ionized water solution.

The high temperature will lead to water evaporation and will increase the acid concentration in the solution. Adding water is dangerous because if too much water is added at once, the solution stops boiling, and the added water will create a film above the acid. The temperature will rise again, and the acid starts boiling, the large quantity of the water from the film mixes with the acid and this may cause an explosive reaction.

That is why the accurate monitoring of the solution is extremely important for safe control of the process.

Modutek's Nb Series Wet Etching Baths ensure the safe operation of silicon nitride etching process. Here, the phosphoric acid solution is kept boiling with a heater that's constantly on which maintains the solution at the boiling point.

One of its features is the heater which constantly keeps the phosphoric acid solution at the boiling point.

Other key features are the thermocouples – the first one detects the rise of temperature (as the water evaporates and the acid concentration increases). In this case, a small amount of water is added to the solution to bring the concentration to back its manageable levels. There's also a second thermocouple which detects the presence of steam above the bath liquid and blocks the addition of water when no steam is present. The third thermocouple monitors the bath temperature to switch off the heater if the solution overheats.

The advanced features of the Modutek's Nb Series Wet Etching Baths allow semiconductor manufacturers and research labs to control the silicon nitride wet etching process safely while achieving optimum consistency characteristics.

The complete article, “Safely Controlling the Silicon Nitride Etching Process,” explains in more details. For a free quote or consultation contact Modutek at 866-803-1533 or email Modutek@modutek.com.

How Quick Dump Rinsers Improve Silicon Wet Etching Results

Manufacturing lines in semiconductor fabrication facilities and research labs use corrosive chemicals in cleaning and etching silicon wafers. A silicon wafer will undergo multiple steps in baths that contain such chemicals as hydrochloric acid or hydrogen peroxide.

Once the cleaning and etching are done, using Quick Dump Rinsers the silicon wafer then undergoes rinsing – the rinsing process should remove the contaminants from the corrosive chemicals completely without introducing new contaminants. The chemicals from the silicon wafer must be completely rinsed before the wafer can undergo further process steps.

If traces of chemicals are not completely removed, etching of the wafer may result in defective and low-quality products. That is why in many process steps, rinser performance is critical for product output quality.

When the wafers are placed into the Quick Dump Rinser tank, powerful jets spray de-ionized water over the wafers to remove all traces of chemicals. As the tank fills up, all the chemical residue and particles are flushed out and rise to the surface. A nitrogen gas bubbler system agitates the de-ionized water further, removing additional contaminants from the surface of the wafers. An overflow weir allows the surface to flush the chemical residues and other impurities out of the tank. Once the rinsing process is complete, the quick dump door at the bottom of the tank opens and drains the water in a matter of seconds.

Modutek's Quick Dump Rinsers are designed to meet the needs of advanced semiconductor fabrication. Their features include:

• Contoured vessel design
• Nitrogen bubble on all models
• Natural polypropylene or PVDF (option) tanks, nozzles and fittings
• Large machined dump door without gaskets or seals
• 360-degree overflow weir

The rinsers are available either as standalone units or integrated into a wet bench process manufacturing line.

The rapid operation of Modutek's Quick Dump Rinsers help reduce the use of de-ionized water as well as save process time. It removes contaminants completely without introducing new chemicals. Modutek has an extensive line of silicon wet etching equipment from which to choose.

For more information read the blog article titled “How Quick Dump Rinsers Improve Silicon Wet Etching Results” . For a free consultation or quote contact Modutek at Modutek@modutek.com or call 866-803-1533 to discuss your specific requirements.

How Quartz Tube Stations Work and the Benefits They Provide

High-temperature operations that include diffusion of materials into the silicon wafers are some of the processing steps involved in the manufacture of semiconductor components. Quartz tubes are the ideal vessel for such processing steps because they can withstand even the highest temperatures and are inert enough to reduce contamination.

Usually, the silicon wafers are placed in a horizontal quartz tube that is big enough to contain wafers and their supports. In horizontal quartz tube cleaning stations, the tube is inserted into the cleaning enclosure and cleaned with an acid spray. The acid dissolves and removes the contaminants from the high temperature furnace. A couple of cycles are then followed: the rinse cycle which removes the traces of the acid, and the drying cycle which speeds up the drying process without introducing particles into the cleaning enclosure. Mechanical handling of the tubes helps in minimizing possible damage due to human error and decreases the chances of contamination from foreign particles.

Modutek’s quartz tube cleaning stations offer a lot of advantages, especially when they're customized to accommodate the requirements of a specific application. Aside from providing customized equipment, Modutek can supply the degree of automation requested by the client. Cleaning process steps can be performed manually or fully automated. Full automation minimizes human error and keeps operators safe by allowing them to remotely monitor the cleaning process.

Modutek's horizontal quartz tube cleaning stations provide an excellent solution for semiconductor manufacturers and research facilities. Rugged and reliable, the basic unit offers many options for additional features according to specific customer requirements such as: holding tanks, automation features, a T/C sheath cleaner or a bottle washer. As a leading semiconductor equipment manufacturer Modutek provides continuous product innovations and improvements and offers the highest degree of customer service and support.

For more details read the complete article “How Quartz Tube Stations Work and the Benefits They Provide”. To discuss your specific needs, contact Modutek at 866-803-1533 or email Modutek@modutek.com to schedule a free consultation.

Why High Temperature Quartz Baths Are Required for Silicon Wafer Cleaning

Silicon wafers undergo many process steps during the manufacture of semiconductor components. Cleaning the wafers properly is a key factor for successful fabrication. These process steps include etching and diffusion, both of which involve the use of a masking material which helps guide the etching chemicals or diffusion targets. When the cleaning is done, the masking material is removed. If traces of contaminants are left or introduced, it will result in an inferior and defective semiconductor product.

Aggressive chemicals are used in silicon wafer cleaning to remove organic masking material and other possible impurities. In this cleaning application, there needs to be a container that can resist the action of these aggressive chemicals, while remaining inert so as not to become the source of contamination itself.

 Quartz baths provide an ideal solution to the challenges of silicon wafer cleaning and for maintaining the high levels of wafer cleanliness. They provide a clean and safe container for silicon wafer cleaning because they can withstand the chemical reactions. Quartz baths typically hold the wafers and the cleaning chemicals, but some processes require heating, circulating the solution or adding chemicals, depending on the various materials used.

Quartz baths are impervious to strong chemicals such as hydrochloric acid, sulfuric acid, and hydrogen peroxide. The baths remain unaffected by these chemicals while the chemicals clean the silicon wafers. With SPM clean, sulfuric acid and hydrogen peroxide are mixed at a constant temperature of 100 degrees centigrade. Periodic spiking of hydrogen peroxide is necessary because it decomposes in the solution. This mixture of these strong chemicals, combined with high temperature, effectively cleans the silicon wafer without affecting the quartz bath container.

The electrical and physical structures that make up the semiconductor components are ultra-sensitive to contaminants. Even a single contaminant can interfere with the entire etching or diffusion process. Such interference from these contaminants can reduce the yield of the semiconductor components and affect the productivity of the semiconductor manufacturing facility. That is why it is extremely important to use bath containers for these process steps — they should be inert and should not become another source of contamination themselves.

If you would like more information about Modutek’s quartz baths, read the complete article “Why High Temperature Quartz Baths Are Required for Silicon Wafer Cleaning”. Contact Modutek at 866–803–1533 for a free consultation to discuss your needs.

Ordering a Wet Bench Station for Your Specific Process Requirements

Semiconductor equipment manufacturers provide equipment that supports complex manufacturing process steps that must be followed and controlled in a very precise manner. The process requirements will typically include cleaning, etching, developing, and stripping along with the proper handling/disposal of caustic chemicals. The physical attributes required in the production line as well as special features (like recirculation and heating) may also have to be considered.

The three main physical factors that influence wet bench equipment specifications include available facility space, wafer size, and wafer throughput. Limited space for new installations or a requirement to integrate with an existing system may require that compact stations be used. Some functions, like rinsing and drying, can be integrated or may need separate spaces. Chemical delivery systems can take space or be placed some distance away or behind the production line.

Throughput is a crucial variable because this affects profitability. Automatic transfer of wafers between stations and automatic process control may save time. How the process is controlled may affect how long a chemical bath can take place without changing the chemicals and the need for downtime for maintenance.

Wet bench equipment and processes (such as RCA clean and Piranha) use aggressive and often dangerous chemicals. Therefore, the equipment should have a strong resistance to such corrosive substances as well as additional features to keep the operators safe.

These attributes can mean that almost every installation of wet bench equipment is customized to some extent. However, only an experienced semiconductor equipment manufacturer can offer a complete line of wet bench stations incorporating the latest technology and using their own software. A manufacturer should also offer other special features such as heating control accuracy and precise calculation of dosages which are essential for high-quality output. Suppliers who manufacture, assemble and develop their own equipment should also be available for complete after-sales support and service.

For more information read the article “Ordering a Wet Bench Station for Your Specific Process Requirements”. If you want a free consultation or have questions, contact Modutek at Modutek@modutek.com or call 866-803-1533.

Selecting Silicon Wet Etching Equipment for Your Application

The use of high quality Silicon wet etching equipment is needed in the manufacture semiconductor components. Selecting the right equipment is essential for maintaining facility performance and excellent product quality. The products produced at manufacturing facilities range from relatively simple electronic parts to complex components with intricate microstructures. With these kinds of varying requirements, most systems must be customized for the specific application.

Selecting silicon wet etching equipment along with any appropriate accessories may require professional and expert help since system parts must be closely integrated and seamlessly move silicon wafers through multiple fabrication steps. Precise chemical dosages, as well as accurate temperature control and exact timing, are important for consistent results.

Tanks and baths
Each of them is specifically made to support certain chemical processes and should be made from high-quality materials to reduce contamination.

Quartz baths — for cleaning processes such as RCA and SPM.
Teflon tanks — for etching applications such as KOH and TMAH.
Stainless steel tanks — for solvent baths.

Automation
Wet benches can be operated manually, semi-automatically, or with full automation.

A manually controlled wet bench allows human operators to set process parameters and calculate chemical doses before beginning and monitoring the process.

A semi-automated wet bench features some process steps that are automated but it still requires the control from the operator.

A fully automated wet bench runs the entire process and improves the performance of silicon wet etching equipment in many ways, which include: reduced human error; reduced chemical use; increased etching accuracy; and improved etch rates.

Modutek provides excellent silicon wet etching equipment and you can learn more by reading the complete article “Selecting Silicon Wet Etching Equipment for Your Application.” You may request a free consultation or more information by contacting Modutek at 866–803–1533 or email Modutek@modutek.com.

How Chemical Delivery Systems Are Customized for Specific Applications

Many industrial plants, factories, and research centers use chemicals in their operations and need systems that can handle and distribute them safely and effectively. Chemical delivery systems need to store chemicals, delivery them to the point of use and also provide control for safe disposal. Depending on the specific application, they may also require features such as chemical mixing and a certain degree of automation.

A chemical delivery system must be reliable, accurate, efficient, safe, reduce chemical waste and provide process repeatability. By incorporating all these factors, the design of a chemical delivery system will have a high degree of customization with many system components and functions.

The volume of chemicals influences the design of the system. For spiking, delivering precise dosages is critical while for bulk chemical use receiving and storage are important. Depending on the volume, a system must be customized to accommodate the volume of required chemicals.

Controls are also customized depending on how chemicals are used. Mixing and blending several chemicals, as well as their level of toxicity and aggressiveness, require a certain amount of software control and a relatively complicated system. Since each chemical delivery system has unique requirements for functions such as mixing, acidity, etching capability and disposal, customized controls are required to achieve these tasks.

Facility layout is another factor that influences the system's design. An ideal layout should be a small storage container near the process where the chemical is being used, although there are other systems wherein the chemical is stored away from the process and pipes are used to dispose the used chemicals. Whatever the case, the physical details of the system must be adjusted for the site layout and site-specific operations.

Read our complete article “How Chemical Delivery Systems Are Customized for Specific Applications” to learn more. Contact Modutek at 866-803-1533 or email to modutek@modutek.com for a free quote or consultation about your requirements.