Tag Archives: improving semiconductor manufacturing

Free Standing IPA Vapor Dryer Improves Wafer Processing

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When a series of semiconductor manufacturing steps are complete, the silicon wafers have to be rinsed and dried. At this stage in the fabrication process, the surface of the silicon wafer has to be as free as possible from particle contamination wafer and free from water marks caused by the water evaporating on the wafer. The free-standing IPA vapor dryer uses IPA (isopropyl alcohol) to eliminate water marks and reduce the particle count. IPA vapor drying, also known as Marangoni drying, delivers clean wafers for improved processing by increasing yield and output quality.

IPA Vapor Drying Works by Removing Water from the Wafer Surface

In IPA vapor drying, the silicon wafers are first rinsed with deionized water. IPA vapor is then introduced into the closed drying chamber. Where the IPA interfaces with the deionized water on the wafer surface, the lower surface tension of the IPA causes the water to flow off the wafer surface, taking impurities with it and leaving the wafer clean and dry.

This method of drying silicon wafers is a good alternative to spin drying because it does not stress the wafers mechanically and leaves no water marks. Rinsing and drying takes place in a single unit, avoiding a transfer of the wafers and eliminating a source of contamination. The IPA drying method can be cost-effective, especially if the consumption of IPA is kept low. IPA drying gives excellent results in terms of low particle counts and wafer cleanliness.

Modutek’s IPA Vapor Dryer Provides Superior Performance with Low Operating Costs

Modutek’s free-standing IPA vapor dryer is made from polypropylene with Teflon fittings and pipes. Its 30-inch wide space-saving design can easily be integrated into a wet processing equipment production line or used independently to rinse and dry wafers. The IPA vapor is introduced at the top of the enclosure from a standard one-gallon bottle located at deck level in the exhaust compartment for easy bottle changes. From the top, the vapor is distributed evenly throughout the chamber. Drying time is typically about ten to fifteen minutes.

In addition to the basic drying function, Modutek’s design also includes de-ionized water degassing, N2 head case purging, and hot N2 drying. The station is operated from a touch screen with an intuitive graphic user interface that allows the programming of multiple operating sequences.

Features include a continuous flow deionized water manifold, an automatic lid that opens with a foot switch, and removable PVC side shields. Options include a manual lid, a quick dump feature, data logging, and the use of ozone to eliminate remaining organic impurities. For special applications, Modutek can adapt the dryer design to meet customer requirements.

Advantages and Benefits of the Free Standing IPA Vapor Dryer

With vapor generation inside the standard bottle and vapor introduction from the top of the enclosure, Modutek’s IPA vapor dryer has a very low IPA consumption and low operating costs. The included features and options along with possible customization allow for flexible operation and make the dryer an ideal addition to a semiconductor fabrication line. Excellent rinsing and drying performance, rapid operation, and programmable cycles deliver superior results and higher throughput. Clean wafers with low particle counts can reduce rejects and improve yield. The flexible design makes the station suitable for production lines, batch processing, and individual prototyping or test products.

Based on the company’s extensive experience in the design and building of semiconductor manufacturing equipment, Modutek can advise customers on the type of system they need and can deliver equipment from its complete line of wet process stations. Modutek designs and builds all its own products in-house and has the expertise to ensure IPA vapor dryers and other equipment meets the needs of customers and performs as required. Contact Modutek for a free quote or consultation to discuss your specific requirements.

Improving Silicon Wafer Processing with High Temperature Quartz Tanks

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Because silicon wafer processing uses acids and bases, the process requires tanks that are impervious to aggressive chemicals. Quartz tanks are stable and do not take part in wet process chemical reactions, even at the high temperatures reached during some of the process steps. Modutek’s quartz tanks use pure flame-polished quartz to reduce impurities that might contaminate the chemical reactions. To keep the temperature at the setpoint, Modutek has added precise temperature controls. As a result, Modutek’s quartz tanks represent an ideal way to implement wet process wafer fabrication steps.

Quartz Tanks Improve Output by Reducing Contamination

The output quality of wet process semiconductor manufacturing is directly affected by contamination during silicon wafer processing. When microscopic particles adhere to wafer surfaces, wafer etching can be disrupted and the semiconductors produced by the manufacturer can be defective or of poor quality. A major concern during silicon wafer processing is the reduction of the particle count on the surface of each wafer.

The high-purity semiconductor grade quartz used in Modutek’s tanks is made up of a crystal lattice containing tightly-held atoms of silicon and oxygen. These elements remain locked in the lattice while the wet process chemical reactions of wafer cleaning, stripping, and etching take place. This ensures that the quartz tanks act as neutral containers and don’t add contaminants or particles to the wafers.

After processing a wafer through one of the many steps of semiconductor manufacturing, a wafer has to be clean and almost completely free of particles. When Modutek’s quartz tanks are used for processing, potential particle contamination from the tanks is significantly reduced. The tanks are based on over 30+ years of bath design and feature a seamless, sloped flange construction. This is especially important for semiconductor manufacturing as industry trends have been moving toward tighter packing and reduced structure sizes. This means even a single small particle can block an etched path or result in a defective structure. By reducing particle counts, Modutek’s quartz tanks improve manufacturing results.

Quartz Tanks with Tight Temperature Control for Improved Etching Precision

The exact shape and location of etched structures in the silicon are critical for the correct functioning of the final semiconductor device. Etching speed determines the shapes of the etched structures in the silicon and the speed is controlled by the chemical concentration and the reaction temperature. The chemical concentration is set at the beginning of the process steps for most of the processes, but the temperature can be used to control the etching speed.

Modutek’s quartz tanks are designed to keep the temperature at exactly the setpoints required for the process and to deliver the anticipated etch speed. The bath temperature can be controlled precisely up to 180 degrees centigrade and the tanks feature a quick temperature rise of up to 2 degrees centigrade per minute with an accuracy of plus/minus 1-degree centigrade.

Heating is even and the fast rate of temperature increase improves throughput. The high accuracy allows precise prediction of etching distances and reliable repeatability of the process when different batches are manufactured. Tank design provides high reliability and safety with a view to a low total cost of ownership.

Using the Right Quartz Tanks Improves Processing and Overall Output Quality

As a leading semiconductor equipment manufacturer, Modutek works with customers to design processing equipment that will help them meet manufacturing requirements. Modutek’s recirculating and constant temperature quartz tanks improve silicon wafer processing by reducing contaminating particle counts and ensuring precise control of etching. The reduced particle counts and the reliable production of required etched shapes reduce defects and rejects in manufactured devices. Contact Modutek for a free consultation and quote on selecting the right equipment to support your manufacturing requirements.