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.
