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.