Monthly Archives: February 2017

Tips on Selecting Wafer Processing Equipment for Your Application

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Tips on Selecting Wafer Processing Equipment for Your ApplicationSemiconductor manufacturing and research facilities use wet bench technology to produce silicon wafers that require many cleaning and etching process steps. The wet bench equipment needs to be flexible and configured for the particular manufacturing process. Ideally equipment should be suitable for both acid and solvent applications with designs based on extensive experience using high quality materials and meeting or exceeding all applicable safety standards. Typical processes used for wafer processing equipment include KOH Etching, BOE (Buffered Oxide Etching), RCA Clean, plating and Megasonic cleaning. For special applications, custom designs to meet specific process requirements may be needed. Depending on the budget framework and the process, wet benches can be fully automated, semi-automated or designed for manual operation.

Fully Automated Stations

Wafer fabrication equipment with full automation offers excellent consistency of process steps and improved output quality. Precise control of chemicals and process times allows for minimization of waste and a reduction of operator errors. A reduced use of chemicals due to exact dosages can save money and effective neutralization of discharges means compliance with environmental regulations is easier. Software calculates the chemical dosages and each process is completely repeatable in a consistent process environment.

Semi-Automated Stations

Semi-automated stations offer the robotics of the fully automated wafer processing equipment without the automation and at a lower cost. The servo-controlled robots with three degrees of freedom produce a uniform process and allow operators to precisely control chemical dosages and process times. Controls are user friendly via a touch screen and software for simulations and dosage calculations is available.

Manual Stations

Stations without automation offer the same high quality process equipment as the automated stations but without the cost of automation. The manual wet benches include all the process and safety features of the automated equipment minus the cost of the robotics. The standard models and customized versions can be adapted for any wet bench processing application and the units are especially attractive due to the low cost of ownership.

Whether they are manual or automated, the process equipment features white polypropylene construction with wiring to NFPA 70 and 79. Safety features include an emergency power off button, safety interlocks and PVC safety shields. Process tanks have a one-inch lip exhaust and the units have a continuous flow DI water manifold along with a Teflon N2 gun and DI water hand spray. Third party certification for NEC and NFPA is available.

All of the wet benches and chemical stations can be ordered as standard units that can process semiconductor wafers up to 12” (300 mm) as well as glass substrates in a variety of sizes up to 30″ x 60″ solar panels. The units can be customized to fulfill any processing, etching or cleaning application. At Modutek, all design, assembly and testing is carried out in house including the writing of the SolidWorks Simulation software.

Modutek’s Wafer Processing Equipment

The Modutek fully automated, semi-automated and manual wet benches meet the highest standards of material quality and safety. All orders are reviewed by Modutek mechanical and electrical engineers and produced based on over 35 years of experience in the industry. The company uses its internal expertise to advise customers on the best equipment to meet their requirements.

Because Modutek writes its own software and builds the wafer processing equipment in house, the company can offer complete customer assistance without going to outside suppliers. Problems are handled internally and customers receive seamless technical support. Modutek’s technical staff can help customers during the ordering process, while manufacturing and assembly is taking place, during factory testing with de-ionized water and with on-site service after delivery. Call Modutek for a free quote and recommendations on using the right wafer processing equipment for your application.

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 Modutek@modutek.com.