The Benefits of Using Modutek’s Quartz Tube Cleaning Solutions

Ultra-clean and reliable quartz tubes are a basic requirement to ensure a precise and smooth semiconductor wafer fabrication process. That’s why quartz tube cleaning stations are required equipment at every semiconductor wafer foundry.

The Quartz tube cleaning process requires the use of corrosive chemicals, and requires the involvement of a manufacturer and installer to design and install units specifically tuned and adjusted to meet the specific application.

Quartz tubes themselves are delicate components, they need to be handled meticulously as they can be prone to risk and damage. The ideal quartz tube cleaning process minimizes human handling at all stages. This is why automated tube cleaning stations are essential equipment for semiconductor manufacturers.  

Fortunately, there are quartz tube cleaning stations today that require minimal human handling at every stage, and Modutek’s quartz tube cleaning stations do exactly just that.

Built out of white polypropylene, Modutek’s quartz tube cleaning stations are designed to keep quartz tubes in motion while they are being etched, and powerful nozzles direct water spray at the quartz tube to maximize coverage.

Units can also be custom-designed and equipped with many other options (such as automation and hot nitrogen drying processes) that can be applied for more efficient cleaning procedures. From automated program recipes to tube roller systems, every part of the process can be made more efficient with automation. Operators using the automated station will simply monitor the process through the data shown on the screen, and can control various functions remotely.

Whether you need a manual or automated quartz tube cleaning station, Modutek designs it for you in house at their facility to ensure excellent and superior performance in any installation.

For more details read the posted article titled “The Benefits of Using Modutek’s Quartz Tube Cleaning Solutions”. If you want a quote or consultation on selecting equipment for your specific application call Modutek at 866-803-1533 or email Modutek@modutek.com.

Custom Fabrication Services for Unique Wafer Processing Requirements

Research labs and semiconductor manufacturing facilities often have special requirements for certain projects or prototypes that may need custom equipment to support their manufacturing procedures.

Semiconductor manufacturing facilities may need customized tanks, carriers or chemical stations to manufacture a particular product or may need to change existing equipment based on external changes or new requirements.

When new products are developed, single items are manufactured, or prototypes are done for testing, existing wafer processing equipment being used may not be suitable for the job. There are many factors: changing suppliers and/or environment and safety regulations imposing additional requirements or changing existing ones. In such cases, retrofitting the equipment, adding new components or changing parts or any other customization may be the best and most cost-effective solution to meet the current requirements.

On the other hand – other semiconductor manufacturers want to customize their existing equipment to let themselves adapt their production lines to current requirements, to speed up production and to increase throughput.

Fortunately, Modutek can provide expertise and experience to manufacturers when customized solutions are needed to support their unique wafer processing equipment requirements.

With over 35 years of experience supporting the needs of the semiconductor manufacturers and research facilities, Modutek specializes in custom design and development. They offer a wide range of customizations that include retrofitting equipment, upgrading stations, improving chemical delivery systems, etc., to meet client specifications, safety standards and environmental regulations. By using their expertise and experience to design and build customized equipment, Modutek’s engineers know exactly what works best and how existing equipment can be modified to meet any specialized requirements.

If you have questions, or would like a free estimate, after reading our full article “Custom Fabrication Services for Unique Wafer Processing Equipment,” please feel free to call Modutek at 866-803-1533 or send an email to Modutek@modutek.com.

Single Wafer Processing Spurs Demand for Wafer Cleaning Equipment

Wafer cleaning equipment suppliers regularly invest heavily in research and development in order to stay abreast of the ever-changing market trends. It also helps them meet the high demands of certain industries such as semiconductors, printed electronics, and single wafer processing.

More and more operators are jumping into the semiconductor equipment industry. Thus, the trend fuels the high demand for wafer cleaning equipment.

Single wafer processing is one of the factors that drive the global wafer cleaning equipment market's continuous growth. Single wafer processing uses ozonized wafer and hydrofluoric acid in a single spin technology to reduce cycle times and boost output flexibility.

Single wafer cleaning equipment becomes competitive but only when the cycle times for individual wafers are low and the quality of the output can be comparable to wet batch processing. It can be used to etch silicon and provide a wet process for mini-fab single wafer cleaning. This process is often done together with megasonic cleaning because it helps in removing the tiniest particles and impurities, resulting in low particle count for the finished substrate.

Some single wafer processes are attractive because their deliver better results than the use of traditional process. The use of megasonic cleaning in particular reduces particle counts for even the smallest particles. The cleaning method uses megasonic sound waves in the cleaning solution which generate cavitation bubbles. These bubbles can remove the very small particles from the substrate surface. This type of cleaning is better than the traditional methods as it uses no harsh chemicals and reduces particle counts.

As semiconductor equipment manufacturers embrace single-wafer processing, the demand for single wafer cleaning equipment will increase significantly.

For more information read the complete article “Single Wafer Processing Spurs Demand for Wafer Cleaning Equipment”. If you would like a free estimate or have questions, contact Modutek by email to Modutek@modutek.com or by calling 866-803-1533.

Advantages of HF-Last Etching and IPA Drying in One Chamber

After cleaning, a silicon wafer needs to be effectively cleaned and dried with no particle contamination. Clean wafers are important to avoid errors in the next processing steps to produce devices that are of superior quality and free from defects. Using the single chamber HF-last and IPA vapor dryer show a considerable reduction in wafer substrate particle counts.

By the final stage of silicon wafer cleaning, the silicon oxide layer has to be removed and the cleaned wafer dried free from contaminants. However, transferring the wafers from the HF etching process to a separate drying chamber will likely cause the wafers to pick up particles.

Modutek now has a solution to this problem: the single-chamber HF-last and IPA vapor dryer, which can help to significantly reduce the particle count on wafer substrates.

In the single chamber process, Modutek uses IPA vapor drying in a free-standing unit with one DI water rinsing and drying. This method, also called the Marangoni drying technique, results in clean wafer substrates -- having no contamination or watermarks.

Modutek has modified the IPA vapor dryer to include HF (hydrofluoric) acid injection before the start of the standard IPA vapor drying process. The HF acid injection ratio is controlled and provides an etch to bare silicon. When the silicon is etched, it is then rinsed to a controlled pH level. Once the appropriate pH levels are reached, it is then followed by the IPA drying process without moving the silicon wafers. This results in the low particle count on the wafer.

Initial field results from the single chamber HF-Last IPA dyer that Modutek has supplied to customers are showing outstanding results. Within the 0.3 to 5 micron range, fewer than 20 particles (adders) were added to etched substrates which are substantially below what was achieved in previous processes in this field trail.

For more details read the complete article “Advantages of HF-Last Etching and IPA Drying in One Chamber” to learn more about Modutek’s IPA vapor dryers. Call Modtuek at 866-803-1533 or send an email to Modutek@modutek.com if you have questions or would like to get a free consultation.

Etching Silicon Wafers Without Hydrofluoric Acid

Hydrogen fluoride is an excellent etching chemical for silicon wet etching in wafer fabrication, etching rapidly to remove silicon oxide, for example, after an initial RCA clean. Although it is effective, hydrogen fluoride is toxic, dangerous and can be deadly if proper procedures are not followed.

Some of the dangers of exposure to hydrofluoric acid include:

• Vapor that can cause lungs to fill up with liquid
• Affects nerves at sites where the skin has been exposed to the acid and initially, the victims may feel a little pain as a result.
• Can penetrate deep into the body and destroy the tissues and bones. This often can cause long-lasting damage.
• Disrupts calcium chemistry of the blood, eventually leading to cardiac arrest.
• Even a small amount can cause skin burns that may be slow to heal. It can also result in death if treatment is delayed.

Hydrofluoric acid is also a hazardous waste and its discharge is tightly regulated. The acid must first be neutralized and the discharge limits on fluoride and metals must be followed. The safety and environmental considerations have resulted in the search for alternatives.

Depending on the specific silicon wet etching application, other etching chemicals may be used which are more suitable and safer replacements for hydrofluoric acid. Some of these include potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH) and nitride etch.

Modutek can help customers make the change by recommending equipment that supports an alternative chemical etchant. The company has over 35 years of experience and expertise in providing wet bench and wafer fabrication equipment and can advise customers about alternatives.

Read the complete article "Etching Silicon Wafers Without Hydrofluoric Acid" to get more details. If you have questions or would like a free quote or consultation, please contact Modutek at 866-803-1533 or email modutek@modutek.com.

Improving Process Control with Fully Automated Wafer Fabrication Equipment

An increasing number of wafer fabrication applications require tight process control. Accurate chemical dosage and precise process timing become critical for a high-quality output.

Manual and semi-automated controls are susceptible to human error and a variation in how process steps are carried out. These processes can be improved with the use of fully-automated wet benches and chemical stations which help with consistent execution.

The combination of fully automated wafer fabrication process and software ensures better repeatability, minimized waste and improved production line performance.

Modutek designs and manufacturers their fully automated wafer fabrication equipment in-house to ensure the highest quality standards are met. In addition, Modutek has developed their own SolidWorks Simulation Professional and SolidWorks Flow Simulation software, which will provide a consistent automated process and ensure correct dosages. The software can also perform simulations and track chemical use.

Modutek offers standard wet bench chemical stations or customized equipment to meet the customers' exact standards and specific application. They can handle both solvent and acid applications, and the equipment can process sizes up to 30 inches by 60 inches.

There are a number of benefits in using fully automated wafer fabrication equipment. The process is set up and can be run repeatedly with minimal monitoring. It also allows for improved process control and accurate chemical dosage, precise timing of process steps, exact replication of the process sequence, and full neutralization of chemical waste. A fully automated process also reduces the use of chemicals. Process output remains consistent, the number of defective results is low, and production line and productivity are improved.

Read the entire article “Improving Process Control with Fully Automated Wafer Fabrication Equipment” and then call Modutek at 866-803-1533 to get a free consultation. You may also send an email to Modutek@modutek.com with any questions you may have.

Modutek Provides Solvent Delivery Pump Station for Large Pharmaceutical Company

Modutek can develop and produce complex and wide-ranging chemical delivery systems that meet challenging customer requirements. As a semiconductor manufacturing company with over 35 years of experience, Modutek delivered its most recent project: providing solvent delivery pump supply for a large pharmaceutical company.

In this project, Modutek supplied nine solvent pumping cabinets, each equipped with two pneumatically-operated pumps. These pumps have pulse dampers and are fitted with air-actuated ball valves on the inlet/outlet of each pump. The pilot valve will regulate the supply of clean, dry air (CDA). A series of valves and monitoring system controls ensures the transfer of solvents to distribution points close to the process.

Each custom-built cabinet has an ultrasonic leak detector housed in a one-inch pipe “T” at the lowest point of the cabinet. The cabinet also features a drain “On/Off” selector and a 4-20 ma pressure transmitter.

The Programmable Logic Controller (PLC) controls these pumps, which in turn will deliver up to four gallons per minute.

When the request for a pump is received, the drain valve “On” function shuts off while the pilot valve supplying CDA to the pump opens. The ball valves then open, allowing the solvent to flow from the pump inlet and past the pressure transmitter to the process.

When the drain valve is turned “On,” the pilot valve, the discharge ball valves, and the pump inlet are disabled. The drain valve opens and the solvent is discharged and transferred into a collection container. Once draining process is completed, the operator can shut off the drain valve, resuming the normal operation of the pumps.

In case the ultrasonic leak detector in the pipe “T” recognizes a leak, the pilot valve, and the corresponding ball valves close, stopping the transfer of the solvent.

Solvents handled include acetone, methanol, ethyl acetate, heptane, isopropyl acetate and methyl tert-butyl ether.

Modutek can help manufacturers with complex chemical delivery systems by developing customized equipment to meet specific requirements. All chemical handling and delivery system equipment designed by Modutek is designed and manufactured in-house at their facility in San Jose California.

If you have questions after reading the complete article “Modutek Provides Solvent Delivery Pump Station for Large Pharmaceutical Company”, contact Modutek for a free consultation at 866-803-1533.

Why Quartz Baths Are Used in the Wafer Cleaning Process

The cleaning of silicon wafers during semiconductor manufacturing uses harsh chemicals to remove deposits from the silicon’s surface.

The semiconductor manufacturing process includes multiple steps, each of which may require cleaning the silicon wafer before or after the production process segment. Highly corrosive chemicals (like sulfuric acid and hydrogen peroxide) are used to remove impurities.

For effective cleaning of the silicon wafer:

·   The contaminants and impurities should be completely removed.
·         The container used should be of an impervious nature.
·         There needs to be tight control of the bath temperature.

Without controlling these three factors during the wafer cleaning process, manufacturing such as diffusion will be affected. Even the smallest remaining particle of contaminant can obstruct an electrical connection and affect electrical characteristics. The resulting semiconductor device will be unreliable or defective.

Baths made from high purity quartz don’t react with the corrosive chemicals used in semiconductor manufacturing and are inert as a source of contamination. Thus, a high-quality quartz bath is an ideal container for the semiconductor wafer cleaning process.

During the cleaning process, the silicon wafers are immersed in a chemical within the quartz bath. The baths may be heated depending on the cleaning process, to a given temperature for a certain time period, and chemicals may be re-circulated. The chemicals in the quartz bath remove organic impurities from the surface of the wafers. Then the step of rinsing and drying the wafers will follow. The wafers are then immersed in a mixture of hydrochloric acid and hydrogen peroxide, where the metallic impurities are removed. After that, the wafers will be subjected to processing steps.

Quartz baths, such as Modutek series QFa re-circulating baths, facilitate reliable cleaning of silicon wafers.

If you have questions about how quartz baths are used in the wafer cleaning process, please read the complete article “Why Quartz Baths Are Used in the Wafer Cleaning Process”. Contact Modutek at 866-803-1533 to discuss your specific wafer cleaning needs.

Selecting Equipment for the KOH Wafer Etching Process

KOH (potassium hydroxide) etching has become increasingly important as a solution in creating microscopic structures in silicon. The wafer etching process using KOH etching is relatively safe and can be monitored by regulating the bath temperature and doping of the silicon.

The silicon wafer (which is masked with a material that's impenetrable by KOH, most often silicon dioxide or silicon nitride) is immersed in the KOH solution. In order to reach a desired etch rate, the temperature must be controlled. KOH etching is extremely sensitive to temperature variations at temperatures at 60 degrees centigrade and above, that's why accurate control of the temperature is a key factor to produce accurate etching results.

Aside from the variations of temperature, the orientation of the crystal planes in the silicon and the doping of the silicon with boron can also significantly affect the rate and the direction of the etch.

Selecting the right KOH equipment will lead to delivering precise etching results you expected. Modutek supports KOH etching as one of the wafer etching process options within their wet bench process stations.  

Modutek's equipment includes the TFa and TT series Teflon heated tanks which are ideal for supporting KOH etching requirements. The tanks are available in standard size (for single or double capacity) or customized sizes.

The TFa series high-temperature overflow tanks and the TT series static tanks are both PFA Teflon tanks with a Teflon-covered liquid path. It also includes the 360-degree overflow filtration through serration overflow, a condensing Teflon refluxor with Teflon cooling units (optional), an aspirator valve system, a pneumatically actuated auto cover, as well as a Teflon gravity drain.

Learn more about “Selecting Equipment for KOH Wafer Etching Process” by reading the main blog article. You contact Modutek at 866-803-1533 for a free consultation or quote, or send an email to modutek@modutek.com.

How Megasonic Cleaning Improves the Silicon Wafer Cleaning Process

The need for effective elimination of contaminants from silicon microscopic circuits has become increasingly important. Megasonic cleaning, which uses sound waves in the MhHz range generated in the cleaning solution will remove particles as small as 0.1 µm which significantly improves cleaning effectiveness.

The traditional cleaning methods of using harsh chemicals may leave small contaminants in place, and lead to the inferior quality or possibly, even failure of the semiconductor components being produced.

The megasonic cleaning system consists of a high-frequency generator, transducers, and cleaning tank that holds the cleaning solution (such as water or a mild cleaning agent) and the parts to be cleaned. The transducers convert the electric signal (which comes from the generator) to sound waves in the MHz frequency range which travel through the cleaning solution. These sound waves generate microscopic cavitation bubbles in the low-pressure wave troughs. These bubbles will then collapse in the high-pressure peaks, and as a result, they produce tiny jets of water. These resulting jets, when hitting the wafer, will dislodge any particle that adheres on the wafer's surface.

The particles will be carried away by the water currents. There are millions and millions of tiny bubbles which ensure that the silicon wafer is thoroughly cleaned. The bubbles can even penetrate into holes, curves, crevices and other microscopic structures, leaving the surface of the silicon wafer completely cleaned.

Modutek’s Megasonic Cleaning System, developed together with megasonic and ultrasonic technology leader Kaijo Corporation, is a superior alternative to the traditional cleaning methods as it only uses sound waves in the MHz range generated in a water cleaning solution. It can help remove particles down to 0.1 µm in size, to prevent them from affecting the silicon fabrication process. Plus, it improves the overall cleaning performance.

Read more details in the recent article titled “How Megasonic Cleaning Improves the Silicon Wafer Cleaning Process” for additional information. If you have questions, contact Modutek for a free consultation or quote or send them via email at Modutek@modutek.com or call 866-803-1533.

Tips on Selecting an Acid Neutralization System for Your Application

Semiconductor fabrication and research facilities that produce acidic effluents from their industrial processes need to incorporate the use acid neutralization systems. Effluents from industrial processes cannot be legally discharged directly into public sewer systems, but can be processed and disposed of in legally acceptable ways. One way to process them is by altering the pH of acidic effluents waste by-products to legally prescribed ranges. Process engineers and facility managers tend to see waste management operations as a challenging issue to administer and control in terms of cost.

That's why an acid neutralization system that uses automation is the best solution for industrial applications. An automated acid neutralization system is easy to use, cost-effective, and complies with environmental laws and regulations. There are two ways to treat acid effluents: continuous-flow processing or batch processing.

1.      Continuous-flow neutralization system
This is where the stream of influent is treated as it is flowing through a pipeline system, prior to discharge. This method works well in applications where there is a high rate of alkaline discharge or the pH of the influent remains stable from one moment to another.

2      Batch neutralization system
This method works better in dealing with the complex highly acidic influents. Batch systems are suitable for the treatment of processes that cannot be relied upon to produce effluents with unstable pH levels. Since the acidic content tends to change, batches of waste need to be collected and treated separately. Batch neutralization system also excels in the treatment influents that are highly complex, such as those containing heavy metal and fluorides. 

Choosing an automated acid neutralization system minimizes operational errors with its highly computerized monitoring at every stage of the process. These systems feature intelligent, sensor-based checks at every point to alert staff of any need for attention, or problems in the process, when that happens.

Read the complete article “Tips on Selecting an Acid Neutralization System for Your Application” for more details. Contact Modutek for a free quote or consultation at 408-362-2000 to discuss your particular acid neutralization needs.

How Teflon Tanks Are Used in Wet Processing Applications

Modutek's Teflon tanks are custom-made and compatible with both new and existing wet processing stations. Their modular configuration makes it easy to install in existing clean room facilities. Modutek can also design and build specific tanks to meet a customer’s requirements. The advanced PFA Teflon welding techniques reduce contamination and undesirable by-products in the process. Heated models are also available for use in processes requiring temperature control.

Modutek's Teflon tanks are available in standard sizes (single or double capacity); the company can also build custom-sized tanks. There are also other features and functions that make the Teflon tanks ideal for various wet bench applications.

Modutek provides three types of Teflon tanks:

·         The "TT series" (ambient temperature baths)

·         The "TI series" (temperature controlled static baths)

·         The "TFa series" (temperature controlled overflow recirculating baths)

Modutek's static and recirculating temperature-controlled Teflon tanks are ideal for anisotropic etching of silicon using KOH (potassium hydroxide) and TMAH (tetramethyl ammonium hydroxide) processes. Process temperature control is accurate to within +/- 0.5 degrees centigrade and an optional Teflon refluxor with Teflon cooling coils is also available. Providing fast and accurate temperature controls lets operators achieve excellent consistency and repeatability for temperature sensitive process for TMAH and KOH etching.

Modutek’s state-of-the-art Teflon tank design, features and functions, result in fewer defects in output and a higher quality control overall. These tanks ensure uniform heating in the bath, rapid but accurate temperature control and process etch variability wafer to wafer less than 2%. Modutek also offers in house maintenance and support for the product.

Read the complete article titled “How Teflon Tanks Are Used in Wet Processing Applications” for more details. Whether you need Teflon tanks or a complete line of wet process semiconductor equipment, Modutek can help determine what the requirements are and suggest optimal equipment solutions. You may contact Modutek at 408-362-2000 for a free consultation and quote.

Tips on Improving Your Silicon Wafer Etching Process

An Improved silicon wafer etching process requires careful selection of the right etching process for the application along with the use of high-quality reliable equipment that supports consistent results.

Wafer etching is a multiple step fabrication process that requires use of different chemical baths to achieve a specific desirable outcome: The process steps include cleaning, masking, etching wafer surfaces or depositing metal. These steps produce microscopic structures in the silicon wafer and produce the required electrical connections. Key factors that contribute to improving etching performance include control of the etching speed and the cleanliness of the fabrication environment. Etching processes typically used include the following:

·         Silicon nitride - is used as a masking material and is etched with a hot phosphoric acid.

·         Piranha etching - is done with a mixture of sulfuric acid and hydrogen peroxide.

·         KOH etching - using a solution of potassium hydroxide, this etching process creates microscopic structures in the silicon.

·         Buffered oxide etching (BOE) - is carried out with a solution of hydrofluoric acid and a buffering agent to etch thin masking films of silicon nitride or silicon dioxide.

Another key factor for improving silicon etching processes is to use wet process equipment from a reliable supplier that provides equipment that meets the specific application requirements. Modutek has over 35 years of experience as an equipment supplier and can advise customers on which equipment will meet all the requirements of their wafer etching application.

While choosing the right wafer etching process for each stage of semiconductor fabrication is important, the design characteristics of the equipment itself is also key to improving etching results. Modutek's etching equipment incorporates critical design features that include:

·         Filtration and flow control

·         Temperature control

·         Tank design

Semiconductor manufacturers and research labs need silicon wafer etching equipment that delivers accurate and repeatable results in a safe and reliable environment. Modutek helps customers improve their silicon wafer etching process by advising them on the proper equipment for certain etching applications and making sure that the equipment delivers accurate and consistent results.

Read the article titled “Tips on Improving Your Silicon Wafer Etching Process” for more details. Call 408-362-2000 if you have questions or would like to discuss how Modutek can help you improve your wafer etching processes.