Tips on Buying Silicon Wafer Cleaning Equipment

Tips on Buying Silicon Wafer Cleaning EquipmentFor all manufacturing involving semiconductors and micro electrical mechanical systems (MEMs), one of the most important requirements is to maintain a precise cleaning process of silicon. This reduces yield problems that occur from both the organic and inorganic residues. As the size geometry and size of semiconductors continue to become smaller, there are higher risks associated with contamination of wafers especially by particle contaminators. For increased efficiency in your manufacturing processes you will need to purchase high quality and reliable silicon wafer cleaning equipment for your manufacturing facility.

Here are 5 factors to consider when shopping for silicon wafer cleaning equipment:

  • Buy from a company with experience and expertise

Silicon wafer cleaners are different from other products you will buy on the market and fit into manufacturing environment.  When you are purchasing this equipment you will need to look for a company that has a proven track record with in-house expertise and support. You also need to confirm that the equipment they provide will meet all of your manufacturing requirements.   Upcoming companies with little experience are likely to sell you substandard products or products that are not fully qualified to meet your requirements. Companies that have been in the field for a long time will offer various equipment options based on their experience working with various customers.

  • Buy equipment manufactured using the latest technology

As the quality and geometry of the MEMs and semiconductors advance, the technology used to make wafer cleaners have also advanced. Finer geometries require finely washed and cleaned silicon unlike in previous years which involved just simple immersions in hot alkaline. The modern cleaning equipment uses megasonic cleaning, centrifugal spraying, and ultrasonic cleaning technologies. The enclosed systems effectively clean all particles and contaminant films. You’re better off buying from a company that implements such advanced technology.

Photoresists require sophisticated cleaning methods like the piranha cleaning process which uses a mixture of sulfuric acid and hydrogen peroxide to clean organic residues off substrates. This process requires that the equipment and procedure used be carefully followed to insure safety.

  • Confirm that the equipment supports user manufacturing requirements

Cleaning equipment will always feature different cleaning aspects. You should check the manufacturer’s specifications to ensure that they match your requirements to ensure optimization of the resource. Wafer cleaners with additional features may be unnecessarily expensive if you never use some of the features.

  • High quality and reliable tools

Money will always be a factor when it comes to purchasing wafer cleaning equipment, but quality and reliability must never be compromised. High quality and reliable equipment will last longer, work better and will not compromise the reputation of the manufacturer.

  • Buy from a company that offers technical support and onsite repair

Many companies will sell you a product, but will not always offer good technical support and onsite repair if there is a problem. If a manufacturer does not offer good technical support or if the system does not work reliably, your manufacturing yields will be compromised. It is advisable to buy from a company that will offer technical support and repair of their wafer cleaning equipment in case of breakdown or malfunction.


With these factors in mind, work with a manufacturing supplier that provides reasonably priced yet effective silicon wafer cleaning equipment that is both efficient and durable. At Modutek Corporation, we strive to do this for all our customers and have been providing the high quality of equipment, service and support for over 30 years. Call us for a free quote at 866-803-1533 or visit our site at

Silicon Wet Etching Using Modutek’s Nitrite Etch Bath

Silicon Wet Etching Using Modutek’s Nitrite Etch Bath

Silicon Wet Etching Using Modutek’s Nitrite Etch Bath

Modutek has been designing and manufacturing Silicon Wet Etching components and related equipment for over 30 years. Their more recent Nitrite Etch Bath products, including the “Nb” series, is an upgrade to their “Na” series. The Silicon Nitride Etch Bath has been designed and engineered to provide unparalleled process control. You can also expect flexibility and safety as key components of these systems.

Part of what makes the Nb Series silicon nitride etch bath stand out is its two-tiered diagnostic system. This allows the user of the system to monitor the temperature at the same time as it maintains the acid-to-water ratio through supplemented D.I. water. This new metering system makes the Nb easier to install. It also allows for service in existing process stations or in new ones.

Some of the benefits of the Silicon Wet Etching system include, but are not limited to, the following:

  • Controlled Nitride Etching
  • Nitride Etch Uniformity
  • Remote DI water metering system
  • Controls chemicals boiling (no “bumping”)

The silicon nitride etches function in a combination fluid – 85% phosphoric acid (H3PO4) and 15% DI water. These fluids boil at 160°C. Since the water will boil off some of the solution as steam, the NbSeries silicon nitride etch bath includes a refluxor which cools the condenser to cause the steam to condensate back to water which maintains the solution. Please be aware, the condensers are not 100% efficient, which will make it necessary to add water to the solution periodically.

Generally, it is discouraged to add water to acid, but it is required in this case. We have determined some safe ways to do this. For instance, if the acid rapidly agitates or boils, you can add a small amount of water which mixes right away. This poses no safety issues. When the water is added to non-boiling acid, the water sits on top of the acid. More water is added to the top layer of the acid. The water will mix as the heat absorbed by the water makes it boil. The water mixes thoroughly with the acid and the correct reaction occurs.

A basic chemistry rules states, “The temperature of a solution cannot rise above its boiling point, except under special circumstances.” The heater on our system does not have to be controlled the way it is required on other systems. If the heater switch is on, the heater is on. By choosing not to regulate the heater, the heat solution is allowed to boil regardless of the concentration. The system keeps it boiling while water is added to adjust the concentration, which remains at the upper set point.

The Silicon Wet Etching and Nitrite Etch Bath systems also include the following features:

  • Etched-foil resistance heater
  • PVDF or Teflon reflluxor with safety cover
  • Vapor thermocouple
  • Uniformity heat transfer
  • Ease of installation and repair for new or existing wet station configurations

System Specifications include the following:

  • Application: Silicon Nitride Etch
  • Operating temperature range: 30 – 180º C
  • Chemical usage: H20, H3PO4
  • Heat-up rate: 2-3 º C per minute (rate affected by size of system)
  • Process temperature control: ± 0.5º C
  • Vapor thermocouple for chemical boiling control
  • PVDF refluxor with Teflon® cooling coils
  • One year warranty

Companies that need additional features may consider any of the following options. Modutek will work with you to design the Silicon Wet Etching system that best meets your company’s needs. Options include, but are not limited to:

  • Teflon® gravity drain system
  • Auto cover which is pneumatically actuated
  • Remote operation timer switches
  • Aspirator valve system
  • Model C1815a process controller/timer
  • RS232 Interface

To learn more about the Silicon Wet Etching products sold by Modutek Corporation, or to learn how our products can be redesigned to work with your Nitride Etch Baths or Quartz Baths and Sub Ambient Systems (BOE), contact us at 866-803-1533.

Advanced Ozone Cleaning Process for Photoresist Strip, Etch and Clean

Advanced Ozone Cleaning Process for Photoresist Strip, Etch and CleanAs a company, are you spending too much money on chemicals and chemical disposal costs? You can save money by using Modutek’s Advanced Ozone Cleaning Process equipment. Modutek will work closely with you to design and manufacture the best possible ozone cleaning process for your application.

Take time to research and discover the advantages of our ozone cleaning process. Awarded with a Green Technology certificate, we can substantially reduce your process chemical dependencies. Our ozone cleaning process can strip, clean or etch your wafers, substrates and solar devices for less than half the cost of conventional technology.

Read More