Using the KOH Etching Process with Modutek’s Teflon Tanks

Potassium hydroxide-KOH etching is an efficient chemical process that allows for precise impressions to be made within a body of silicon. The process uses DI (deionized) water in combination with heavy alkalinity (pH levels greater than 12); the solution is then thermally adjusted for the appropriate degree of etching needed. This process allows for greater precision than other forms of etching when it comes to manufacturing silicon wafers.

What Are the Benefits of Using KOH Etching?

The precision KOH etching grants is very beneficial to the product’s outcome. Due to its chemical composure and procedural approach, dry etching is more apt to create physical flaws; it also can make for a more hazardous environment, as it risks the exposure of toxic — even explosive — chemicals.

KOH etching, on the other hand, is almost entirely aquatic. The liquids for the etching process are contained within Modutek’s own Teflon Tanks, meaning that exposure to hazardous chemicals is drastically reduced to create a safe environment for manufacturing. The structuring behind the process also means that it can easily be set up for repeat manufacturing; the resources required for the etching are more stable and affordable, meaning that clients can duplicate their etchings at a much more feasible rate.

How Do Teflon Tanks Bolster the KOH Etching Process?

Modutek’s Teflon Tanks are designed with the foresight to emphasize the maximum potential KOH etching can provide. Furthermore, each Teflon Tank is fashioned to cater to the specific needs of the client, regardless of unorthodoxy. In unison with wet bench equipment, these Teflon Tanks greatly reduce the impurities other methods of etching may establish, providing you with a more reliable and consistent output every time.

The Teflon Tanks can be thermally adjusted to operate between 30 — 100º C (86 — 212º F), and on average can heat up at a rate of 2 — 3º C per minute, though smaller or larger tanks may have varying thermal increase rates. Thermal output can be mustered either from inline Teflon heating, or from submersion within an overflow bank for each type of Teflon Tank. Each tank is also fitted with cooling coils that can quickly reduce the solution’s temperature.

There are two types of Teflon Tanks that support KOH etching: Temperature Controlled Re-circulating Baths (TFa Series), and Temperature Controlled Static Baths (TI Series). These two series of Teflon Tanks are designed with overlapping covers to minimize the loss of water during the etching process; they also boast the ability to eliminate concentration deficiency.

Because Modutek designs their Teflon Tanks with the client’s specifications in mind, the customization each tank receives is advantageous to the desired end result. Dual heating methods produce a quick, balanced aid to water-based etching. Drains and valves can be installed into the tanks for safe and easy clean-up. Remote timers, controllers, or even a data interface can be equipped to make a simple process even simpler.

When compared to other forms of etching (whether wet or dry), Modutek’s support of KOH etching produces more precise and affordable results in a safer and more expeditious work environment. Teflon Tanks can be produced individually or en masse depending on the output the client is in need of. Each tank can also be fitted with a number of practical options that can improve the etching process dramatically.

No client should work with an environment or product that diminishes the quality of their manufacturing process; customization leads the way for an innovative and effective product. Modutek’s support of KOH etching in their catalytic Teflon Tanks will provide exceptional results for clients that use this process.

Benefits of Using Quick Dump Rinsers for Silicon Wet Etching

Benefits for Using Quick Dump Rinsers for Silicon Wet EtchingQuick Dump Rinsers are used during the rinse cycle in the silicon wet etching process. The deionized water (DI) rinse cycle is a vital step in your wafer manufacturing process. In fact, DI water probably contacts your product more than any process solution. This makes an efficient rinsing system invaluable to particle and defect density reduction. Fortunately, Modutek Corporation offers the DR Series Quick Dump Rinser for thorough, economical cleaning. Their experienced specialists can upgrade existing rinsing modules and install fresh-from-the-factory wet bench process stations to suit your specific needs.

Features and Functionality

For optimal operations, Modutek includes two defining features into each DR Series Quick Dump Rinser: limited DI water use and easy installation into new or used stations. These properties complement complete rinsing enhanced by:

  • Ergonomic DI water spray nozzles
  • N2 agitation
  • Bottom filling
  • Optional rinse tank vortex agitation
  • Dual overhead spray manifolds

In addition, Modutek has reduced the interior volume of their Rinsers to suit the size of your wafer cassettes. This design expedites dump time through a large, machined dump door and utilizes a surrounding overflow weir to remove all contaminates while preventing recontamination on wafer surfaces.

A Compatible Controller 

Complete your DR Series Quick Dump Rinser with Modutek’s compatible C15sa Rinser Controller. Designed specifically for the wafer rinse module, the controller provides convenience with a high degree of adjustability. Engineers program the fill and dump cycles and initiate cascade and spray delay at the click of a button. Safety features include access code-protected resistivity to prevent unwanted changes to the program.

A Monitored Rinse

Use the Modutek Resistivity Monitor RM30a with the DR Series wafer rinse system for a meticulous oversight of your cleaning process. Along with measuring resistivity, the optional RM30a monitors in flowing water into your wet bench station and internal temperatures of the DR Series rinse system. For minimal DI water consumption, rinse cycles automatically finish after reaching the resistivity setting. This ensures a fully adjustable, conservative rinse.

Whether you desire to upgrade your old rinse system or customize a new wet bench, the Modutek DR Series Quick Dump Rinser installs seamlessly. Even if you choose the latter, Modutek’s rinse system design ensures you save money on water costs throughout years of operation. Also don’t forget to consider increased throughput on all of your manufacturing projects.

Modutek has over 30 years of experience in providing reliable wet bench equipment for all processes in silicon wet etching. Certified specialists will guide you through from design to installation and can provide a free quote on equipment to meet your specific requirements. Call Modutek at 866-803-1533 or an email to