Commercial Market Opportunities for MEMS Technology

Using KOH Etching for Batch ProcessingMicro-electro-mechanical systems (MEMS) is a technology that incorporates the use of microscopic devices ranging in size from several millimeters to less than one micron. They usually have both electrical and mechanical functions and often include parts that can move in response to process conditions, commands from outside the structure or commands from integrated electronics. Typical miniaturized MEMS devices include sensors, actuators and other microscopic structures manufactured on silicon wafers using similar techniques as for semiconductors. They are popular because they are inexpensive to fabricate and are easily integrated into systems containing electronic controls, often on the same silicon wafer.

MEMS Applications

MEMS were first used in the automotive industry and then found increased application in the medical and optical fields. Typical macroscopic functions that were taken over by MEMS counterparts were pressure sensors, inertial sensors and chemical sensors. The MEMS sensors were less expensive to manufacture and performed better than the corresponding large sensors. In addition, different sensors could be placed on one silicon wafer along with signal processing electronics. For example, one unit could measure chemical pressure, detect impurities and generate alarm signals.

As MEMS fabrication methods became more sophisticated, the systems were able to take on additional functions and include different structures. For example, today’s MEMS can include mirrors, gears, pumps, nozzles and valves. Associated electronics can evaluate the signals, perform complex analysis and send results to external receivers via radio frequency elements. Such devices are found in the automotive industry in car airbags, tires and fuel systems. Technical products such as ink jet printers, digital projectors, bar code readers and display screens use MEMS to reduce costs and miniaturize components. Medical systems and devices use the miniature MEMS for diabetic evaluation, insulin delivery, blood analysis and needle less injectors. As the number of applications increases, the market for MEMS continues to grow as does the interest in inexpensive, reliable and rapid fabrication methods.

How MEMS are Produced

To create the microscopic structures that make up MEMS, manufacturers use technology similar to that used to produce microelectronics. For silicon wafer based MEMS, the wafers are masked, etched and cleaned in multiple steps. Silicon wet etching is one method that offers a number of advantages.

Wet etching with potassium hydroxide, or KOH etching, is inexpensive and reliable. KOH is safe and etches quickly. Repeatability is good and the process can be controlled by changing the temperature, the concentration of KOH, the crystal plane orientation of the silicon and the doping concentration. The KOH process allows for very precise etching and it can be automated. Other methods of creating microscopic structures on silicon wafers are more expensive, more risky or not as reliable.

Modutek’s Support for the KOH Etching Process

Modutek offers a variety of wet bench processing options including KOH etching. The company’s KOH silicon etching tank is designed and manufactured in house and can be built to customer specifications to satisfy specific wet process requirements. Its design emphasizes cleanliness with an all-PFA construction and consistency in the process to deliver accurate etching results.

The tanks are manufactured to reduce impurities and contaminants to a minimum with the PFA sheet material welded together using advanced welding techniques. The resulting process tanks deliver excellent performance and high quality output. Custom installations to work with existing wet bench equipment are available. Modutek uses its experience in the wet bench process to ensure that customer needs are met and the equipment functions as expected. If you have challenging wet processing applications contact Modutek for a free quote or consultation on solutions that will address your requirements.

Choosing the Right Chemical Delivery System for Your Application

Choosing the Right Chemical Delivery System for Your ApplicationSemiconductor manufacturers and research labs have extensive chemical handling requirements and need a safe way to supply chemicals to the points where they are used. Key factors for choosing chemical delivery systems are the storage options that are available, the system performance in terms of precision and reliability and the software that can be used to ensure safe and accurate operation.

The chemical delivery systems have to be able to receive the chemicals in bulk, store them safely and conveniently, supply them to the point of use in the required quantities, neutralize them as needed and dispose of them appropriately. Custom configurations, fast chemical change and control options may also be important. Suppliers have to be able to evaluate customer needs and make recommendations based on their experience with chemical delivery systems.

Chemical Delivery System Features

An ideal chemical delivery system improves facility or manufacturing line performance by increasing throughput and producing better quality output. It accomplishes this by reducing manual interventions that can slow down the process and introduce errors. When chemicals are supplied to the point of use exactly as they are needed and with the exact composition required by the process, the facility can operate at optimal efficiency.

A key component of a chemical delivery system is chemical storage. Storage space near the process is often limited but adequate storage to avoid frequent container changes is needed. Ideally the chemical delivery system can continue to operate with integrated storage while a main storage container is being changed.

The mixing and delivery of chemicals to the point of use has to be safe, precise and reliable. Software can calculate the precise amounts needed while monitoring sensors can show chemical paths, levels and other process variables. Extensive and flexible control configurations let customers choose exactly how the chemical delivery system will operate. High quality materials ensure reliable operation and long-term safety. Facility managers and engineers choosing a chemical delivery system have to evaluate such features and check which suppliers have the expertise to recommend a good fit for their needs.

Modutek’s Chemical Delivery Systems
Modutek’s advanced chemical delivery systems provide all the required features and functionality mentioned above. Large tote chemical containers with load cell interfaces can eliminate the need for frequent drum changes when large volumes of chemicals are used. For smaller quantities, a 55-gallon drum system is available and both storage systems are designed for quick chemical changes. Systems have all-Teflon fluid paths with leak detection and sensing of up to four levels. The automated chemical deliveries are displayed on a touch screen that also shows the status of key components such as valves, pumps and alarms. Modutek’s SolidWorks Flow Simulation and SolidWorks Simulation Professional provide accurate chemical delivery calculations and the Modutek systems can be integrated with the company’s own wet processing equipment or adapted for each customer.

Modutek’s chemical delivery systems use software and components that are designed and manufactured at the company’s San Jose, California facility. As a result, Modutek can offer unparalleled service for all its equipment and can prepare custom designs for specialized requests. In addition to providing chemical delivery systems for wet process stations, Modutek systems are suitable for tech benches, plating stations, fume hoods, cleaning stations and acid exhaust hoods. By eliminating manual operator interfaces and ensuring accurate chemical concentrations and mixtures, the Modutek chemical delivery systems can help with increasing facility efficiency and reducing failure rates. If you need a reliable chemical delivery system for your application, contact Modutek for a free quote or consultation.