How the IPA Vapor Dryer Provides Superior Wafer Processing

After etching and rinsing, an IPA (isopropyl alcohol) vapor dryer can produce dry silicon wafers without watermarks and limited particle adders. IPA drying is also known as Marangoni drying, relies on the Marangoni effect of low surface tension of IPA compared to water.

When IPA vapor is introduced into the drying chamber in an IPA vapor dryer, a surface tension gradient is established between the IPA and water on the surfaces of the silicon wafers. The surface tension gradient causes water to flow off the silicon wafers and they are left clean and dry. In addition, the slow drain of water feature also helps to minimize particles that contaminate the wafer surfaces. It results to clean wafers after a final etch and before the next semiconductor manufacturing step.

IPA vapor dryers are particularly suitable for drying thin, delicate silicon wafers. It dries the wafers without moving them, unlike in other drying methods, and they are not subjected to any stress. As a result, any damage is minimized while the drying performance remains excellent.

The IPA vapor dryer improves wafer processing after the final hydrofluoric acid etching. The wafer has to be rinsed with de-ionized water and dried before undergoing the next manufacturing step. Providing a clean wafer with a low particle count is crucial at this stage because the following process steps will be affected by the presence of leftover contamination or particles. Because IPA vapor dryers remove water from the water surface and reduce particle counts with the Marangoni effect, the IPA vapor dryers improve wet processing equipment results and ensure higher quality output.

The complete article, “How the IPA Vapor Dryer Provides Superior Wafer Processing” goes into further detail. If you have questions, or you would like to set up a free consultation, contact Modutek at 866-803-1533 or email Modutek@modutek.com.

How the IPA Vapor Dryer Improves Wafer Processing Results

Silicon wafers require cleaning, rinsing, and drying at certain stages of the fabrication process. The results need to be as flawless as possible, leaving no watermarks and only minimal particle contamination. However incorrect cleaning and drying may lead to contamination, which can cause serious product malfunction and high failure rates. That’s why many semiconductor manufacturers and research facilities use an IPA Vapor Dryer.

Simple methods like rapid spinning and heat drying will no longer work with the latest high-density wafers. Since water is hard to remove from these complex shapes, drying without leaving watermarks is essentially impossible.

This is why cleaning with isopropyl alcohol (IPA) is necessary. IPA drying using the vapor method delivers wafers that are completely free of watermarks and with minimal contamination. Modutek’s IPA vapor dryer features a design which obtains high-quality results by serving IPA vapor at the upper reaches of the drying tank, which ensures the distribution is even. Since the IPA's surface tension is lower than that of water, such vapor serving introduces a gradient of surface tension where IPA meets with a layer of water on the water surface.

Using the “Marangoni drying effect” water quickly leaves the surface and leaves the surface completely dried and clean. Since water never actually evaporates, it leaves no watermarks behind. Ozone is applied into the drying tank to make sure that the drying process does not leave any trace of contamination. The process takes no longer than 15 minutes.

Modutek's in-house team of experts in IPA vapor dryer design will work with a client’s technical team to design and create IPA Vapor Dryers that will specifically meet their application requirements. Clients can also come to Modutek’s facility to review testing results and confirm the equipment will work as needed.

Read the complete article “How the IPA Vapor Dryer Improves Wafer Processing Results” to learn more about Modutek’s IPA vapor dryers. For a free consultation or quote contact Modutek at modutek@modutek.com or call 866-803-1533.

Advantages of HF-Last Etching and IPA Drying in One Chamber

After cleaning, a silicon wafer needs to be effectively cleaned and dried with no particle contamination. Clean wafers are important to avoid errors in the next processing steps to produce devices that are of superior quality and free from defects. Using the single chamber HF-last and IPA vapor dryer show a considerable reduction in wafer substrate particle counts.

By the final stage of silicon wafer cleaning, the silicon oxide layer has to be removed and the cleaned wafer dried free from contaminants. However, transferring the wafers from the HF etching process to a separate drying chamber will likely cause the wafers to pick up particles.

Modutek now has a solution to this problem: the single-chamber HF-last and IPA vapor dryer, which can help to significantly reduce the particle count on wafer substrates.

In the single chamber process, Modutek uses IPA vapor drying in a free-standing unit with one DI water rinsing and drying. This method, also called the Marangoni drying technique, results in clean wafer substrates -- having no contamination or watermarks.

Modutek has modified the IPA vapor dryer to include HF (hydrofluoric) acid injection before the start of the standard IPA vapor drying process. The HF acid injection ratio is controlled and provides an etch to bare silicon. When the silicon is etched, it is then rinsed to a controlled pH level. Once the appropriate pH levels are reached, it is then followed by the IPA drying process without moving the silicon wafers. This results in the low particle count on the wafer.

Initial field results from the single chamber HF-Last IPA dyer that Modutek has supplied to customers are showing outstanding results. Within the 0.3 to 5 micron range, fewer than 20 particles (adders) were added to etched substrates which are substantially below what was achieved in previous processes in this field trail.

For more details read the complete article “Advantages of HF-Last Etching and IPA Drying in One Chamber” to learn more about Modutek’s IPA vapor dryers. Call Modtuek at 866-803-1533 or send an email to Modutek@modutek.com if you have questions or would like to get a free consultation.

How Marangoni Drying Produces Superior Surface Conditioning for Wafer Processing

In the final step of silicon wafer processing, wafers often have to be cleaned, rinsed, and dried. They must be free of any contamination or water marks. Contamination in silicon wafers leads to defects in the next processing steps or to high failure as the impurities negatively impacts their quality. IPA drying using the Marangoni drying effect results to dry silicon wafer surfaces without leaving any residues or water marks.

Modutek's standalone IPA vapor dryer is ideal for this drying procedure. There, the IPA vapor is introduced at the top of the drying tank. The Marangoni drying effect takes place -- since the IPA has a lower tension surface than water, it introduces a surface tension gradient where it interfaces with the water on the wafer surface. As a result, the water flows away from the surface of the wafer, leaving it completely clean and dry, with no watermarks whatsoever. The departing water, meanwhile, carries the impurities or particles that are suspended within it.

Modutek's IPA vapor dryer consists of a wide cabinet built of polypropylene construction which is fitted with Teflon (including its valves and tubes). Operation can be controlled by the menu on the touch screen. The dryer options include PVC construction, a manual lid, and a quick dump feature. Modutek can also customize the dryer to meet customer specifications.

Modutek's IPA vapor dryer is cost-effective and can be incorporated in a wet bench process without the need to add drying transfer steps. Read our complete article “How Marangoni Drying Produces Superior Surface Conditioning for Wafer Processing” to learn more about Modutek’s Marangoni drying. You may also contact us at Modutek@Modutek.com if you would like additional information.

How the IPA Vapor Dryer Improves Wafer Processing Time

The IPA Vapor Dryer from Modutek meets the demands of facilities and process engineers who are continually looking for ways to improve silicon wafer processing time. This system includes the SolidWorks Flow Simulation and Simulation Professional software to ensure improved operations and drying time with one or two 150-450mm cassettes or glass substrates.

Modutek’s IPA Vapor Dryer design has both rinsing and drying capabilities. This Marangoni drying system incorporates a single chamber to facilitate the final stages of the cleaning process. The system provides high throughput along with other advantages including:

·         elimination of watermarks on substrates and hydrophilic/hydrophobic films with no feature damage

·         15-minute batch drying for most applications

·         secure system interface bottle change that allows for fast, deck-level applications

The IPA Vapor Dryer also has a variety of additional safety features and optional features to provide optimal wafer processing with wet processing equipment. If you have questions, call 866-803-1533 or send an email to sales@modutek.com for answers.

Using RCA Clean in a Wet Bench Process

A wet bench process is a procedure involving the removal of organic residues from a silicon wafer and replacement of the surface layer of oxide with a new, thin layer. Semiconductor process engineers do this process first before processing silicon wafers under high temperatures.

SC-1 and the SC-2 are the solutions applied in this process.

The SC-1 removes impurities sticking to the silicon, quartz, and oxide surfaces in a 15-minute soak. It also gives way to regeneration of surface oxide layers.

After the SC-1 application, the wafer is soaked in SC-2 for 10 minutes. This eliminates other impurities such as microscopic metal hydroxides and alkali residues, ensuring that the silicon is thoroughly clean.

Modutek produces high-quality and technologically advanced wet bench processing equipment suited for RCA clean. Modutek also has IPA Vapor Dryers which can be incorporated to your wet bench and finalizes the cleaning process.

Learn about the Advantages of Modutek Corporation’s IPA Vapor Dryer

Using a Marangoni Drying system, more commonly called IPA Vapor Dryer, is the current gold-standard drying method in semiconductor manufacturing and related industries. Modutek Corporation’s free standing IPA Vapor Dryer system uses one standard gallon bottle, allowing quick, uncomplicated bottle changes, thus eliminating down time. There are more advantages to using the Modutek Corporation IPA Vapor Dryer.

Marangoni Drying, first developed in 1990, is now the most popular method for semiconductor manufacture. IPA vapor drying produces an ultra clean, dry surface on a wafer or flat substrate. Nitrogen gas is used to break the wetting film’s surface tension, drying the substrate while the water/IPA gradually drains around the substrate wafer. The surface dries without feature damage or a watermark, with incredibly low particle counts.

The IPA (isopropyl alcohol) Vapor drying process has these benefits:

• Unlike spin-drying, the Modutek Corporation IPA Vapor Dryer doesn’t have moving parts, allowing the manufacture of thinner wafer substrates.
• Particle contamination caused by evaporation residues (a common problem in spin rinse dryers) is greatly reduced using IPA Vapor Dryers.
• The unique IPA Vapor Dryer system uses fewer chemicals than other drying processors. This reduces both the environmental impact as well as the costs of acquiring and disposing of chemicals.
• Quicker drying times (as quick as 10 to 15 minutes) reduces productions costs, while no moving parts reduces maintenance requirements.
• The IPA Vapor Dryer’s lower particle counts make it the superior drying process choice.
• Outstanding for high aspect ratio structures.
• The reduced possibility of substrate breakage during the IPA Vapor Dryer cleaning and drying process reduces production costs.
• An IPA Vapor Dryer increases production of quality substrates. With no electro-static build up between metallic surfaces and therefore no discharge, possible damage is avoided.
• The IPA Vapor Dryer prevents yield loss from watermarks, which is a common problem in other processes, but non existent with IPA vapor drying.

Not just the semiconductor industry, but industries dependent on them profit from the use of the IPA Vapor Drying system. Industries manufacturing products as varied as solar panels or computer disk drives, and any manufacturers using electro-chemical cells will benefit from this technology. The superior substrates manufactured by IPA Vapor Drying will be of great use to companies using micro-electronic mechanical systems (MEMS), including the medical equipment and automotive industries.

Consider Modutek Corporation’s IPA Vapor Dryer for your next drying process upgrade. Call us today at 866-803-1533 to discuss your requirements and to get a quote.