Tag Archives: Marangoni drying effect

Advanced Wafer Drying using Modutek’s IPA Vapor Dryer

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Advanced Wafer Drying using Modutek's IPA Vapor DryerThe successful manufacture of tightly packed semiconductor products depends on obtaining low particle counts on silicon wafer surfaces after rinsing. Heat drying and spin dryers may leave water marks and residue as the water evaporates. Modutek’s advanced IPA vapor dryers use the Marangoni drying effect to reduce particle counts to a minimum. The compact dryer unit can be integrated into wet processing equipment as needed. Modutek’s IPA vapor dryers can increase yields and improve output quality based on reduced particle counts compared to other drying methods.

How the IPA Vapor Dryer Works

In Modutek’s IPA Vapor dryer, an even vapor distribution is ensured by introducing the IPA vapor at the top of the dryer. The vapor is generated in a standard one-gallon bottle located in the exhaust compartment and fitted with a level sensor. Changing the bottle is quick and easy. This arrangement reduces IPA consumption but allows enough vapor to develop the surface tension gradient. As water drains from the bath and runs off the silicon wafer, a small amount of IPA vapor interacts with the thin film of water still coating the wafer. Because IPA has a lower surface tension than water, the surface tension gradient causes the water to flow off the wafer surface. As the water retreats, its flow takes along contaminating particles and other impurities, leaving the wafer completely clean. Because no water is left on the wafer surface, water marks from evaporating water are eliminated.

Advanced Wafer Drying Delivers Many Advantages

The main advantage of using Modutek’s IPA vapor dryer is the reduced particle count. Spin dryers can add particles from the centrifugal action of the spinning. Also, some water will be left to dry, leaving water marks. The Marangoni drying effect utilized in the IPA Vapor Dryer significantly improves wafer cleanliness. Other advantages of Modutek’s dryer include compact installation, low IPA use, and a simple design with no moving parts. The dryer design is flexible enough so that it can be integrated into wet processing equipment. The dryer function can use the same tank as rinsing to save space with a single cabinet. Since the wafers don’t spin, there is no risk of breakage, and a typical drying cycle is completed in ten to fifteen minutes.

The Use of Modutek’s IPA Dryer Can Provide Substantial Benefits

A semiconductor manufacturer can reap substantial benefits when Modutek’s IPA vapor dryer is integrated into wet processing equipment. These include the following:

  • Higher throughput due to faster drying times
  • Higher yields due to fewer defects from contaminating particles
  • Lower costs because of low IPA consumption
  • Reduced space due to compact cabinet construction and integration with rinsing
  • No IPA heating required
  • Flexibility due to multiple drying recipes
  • Easy operation with PLC and touchscreen
  • Safe operation with safety interlocks, auto lid, and PVC side shields
  • Interface capable of working with robotics in wet bench
  • No breakage from spinning because there are no moving parts

Additional Features for Specific Applications

In addition to the direct benefits listed above, Modutek’s dryer can be adapted to specific wet process applications. Possible options include an ozone feature that introduces ozone into the cabinet, a quick dump feature, a static eliminator, data logging, and fire suppression. The dryer can handle all wafer sizes and most glass substrates.

Modutek Provides Solutions to Meet Customer Needs  

Modutek understands wet-process semiconductor manufacturing and has the in-house expertise to find the best solutions. When working with customers, Modutek can evaluate customer needs and make specific proposals from their complete line of wet-processing equipment. After delivery and installation, Modutek provides unparalleled support to ensure the equipment continues to meet customer expectations.

How the IPA Vapor Dryer Improves Wafer Processing Results

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Not every advancement in semiconductor fabrication produces results that are usable in industry. To be of value, advancements need to be consistently repeatable when used on an industrial scale. Modutek’s IPA vapor dryer falls into this category, helping semiconductor fabricators improve both yields and processing times.

Modutek’s IPA vapor dryers are custom-engineered with in-house experts working in partnership with a client’s technical staff. From a thorough understanding of a client’s manufacturing process, Modutek works to make sure their equipment is designed and tested to meet the requirements.

The Marangoni IPA Vapor Dryer Design

Silicon wafers require cleaning, rinsing and drying at certain stages of the fabrication process. The results need to be as close to perfection as possible, with no watermarks, and minimal particle contamination. In the past, these results were obtained through rapid spinning and heat drying. These simple methods no longer work with the latest high-density wafers, however. Not only is water hard to remove from complex shapes, drying without leaving watermarks is impossible.

Contamination from incorrect cleaning and drying can cause serious product malfunction and high failure rates. This is where drying by isopropyl alcohol comes into play. IPA drying by the vapor method, delivers wafers that are completely free of watermarks and with minimal contamination. Modutek’s IPA vapor drying system is both cost-effective, and ready for seamless integration into the standard wet bench process or free-standing design.

How the IPA Vapor Dryer Design Works

Modutek’s IPA vapor dryer design is unique in a number of ways. This design delivers high-quality results through serving IPA vapor at the upper reaches of the drying tank. This makes sure that vapor distribution is even. Since the surface tension of isopropyl alcohol is lower than that of water, such vapor serving introduces a gradient of surface tension where isopropyl alcohol meets with a layer of water on the wafer surface. With this type of drying effect, water quickly leaves the wafer surface, and leaves it completely dry and clean. Since the water does not actually evaporate, it leaves the watermarks behind. The drying process takes no longer than 15 minutes.

The Advantages of Modutek’s IPA Vapor Dryer

Modutek’s in house experts in IPA vapor dryer design work together with a clients’ technical team to design and create IPA dryers that specifically meet their application requirements. Clients are able to come to Modutek’s facility for testing to make sure that their equipment works as expected.

With extensive experience in the wafer processing industry, Modutek is fully able to provide top-notch equipment and customer support at every stage of the design process, during delivery and after the sale. With expertise in semiconductor processing equipment, Modutek is able to address every specific client need for this industry. Contact Modutek for free consultation on the equipment needed for your specific wafer manufacturing process.

 

 

 

How Marangoni Drying Produces Superior Surface Conditioning for Wafer Processing

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How Marangoni Drying Produces Superior Surface Conditioning for Wafer ProcessingAt the end of a particular step in silicon wafer processing, wafers often have to be cleaned, rinsed and dried. The resulting wafer surfaces must be free of water, watermarks, particles and organic residues. Older technologies such as spinning the wafers rapidly or heat drying can no longer fulfill the requirements of high density electronic devices on today’s silicon wafers. Water is hard to remove completely from complicated geometries and drying can leave contaminating watermarks and particles.

Such contamination can lead to product defects in subsequent processing steps or to high failure rates as the contamination impacts quality. IPA (isopropyl alcohol) drying using the Marangoni drying effect leads to dry silicon wafer surfaces without watermarks or particles. Modutek’s IPA vapor dryer is cost effective and can be integrated in a wet bench process without adding drying transfer steps.

How it Works

In Modutek’ IPA drying process, IPA vapor is introduced at the top of the drying tank to ensure even vapor distribution. Because the IPA has a lower surface tension than water, it introduces a surface tension gradient where it interfaces with the water on the wafer surface. As a result of the Marangoni drying effect, water flows off the surface of the silicon wafer and leaves it dry and clean.

The departing water also takes along any impurities or particles suspended within it. No watermarks are present because the water does not dry on the wafer surface and ozone can be introduced into the drying tank to eliminate trace organic contamination. There are no moving parts inside the chamber so physical wafer damage is eliminated and drying cycles typically last ten to fifteen minutes.

Modutek’s Design

The stand-alone Modutek IPA dryer is a 30″ wide cabinet of polypropylene construction. It features wiring to NFPA 70 & 79 and has all Teflon fitting, valves and tubes. A touch screen controls operation with a graphic user interface and the dryer has a multiple recipe function.

The unit has an N2 head case purge with an interlock, a hot N2 dry feature, a continuous flow DI water manifold and an auto lid with foot switch open. PVC side shields are removable and there is DI water degassing function using a membrane contactor. Third party certification for NEC and NFPA is available.

Dryer options include PVC construction, a manual lid and a quick dump feature. Data logging and online support are available. Other options include a static eliminator, resistivity monitoring, HEPA fan filter units and a fire suppression system. Modutek can customize any dryer to customer specifications.

IPA Dryer Operation

The Modutek MVD series IPA dryer is a competitive solution with a single drying chamber for DI water rinsing and IPA vapor drying. The IPA vapor is generated in a one gallon bottle installed at deck level for easy changing. Introducing the vapor at the top of the tank is an efficient way of achieving even distribution of the vapor and reduces IPA consumption. The dryer can handle all wafer sizes and glass substrates and Modutek can integrate the IPA drying function into wet bench stations to eliminate a transfer step.

Benefits of Modutek’s IPA Vapor Dryer

Modutek’s specialists work with customer engineering teams to design a dryer that best matches the process application. Modutek’s design and software implementations are all carried out in house and acceptance testing with de-ionized water is available. The company’s extensive experience in the semiconductor manufacturing industry lets it provide first class customer support at all stages of a contract and after delivery. If you need to improve your wafer processing quality and want a free consultation or quote on using an IPA Vapor Dryer, call Modutek or email [email protected].