Industry Newsletter Microelectronics 6
MicroelectronicsPerspectives in Pure Water Analytics6NewsTHORNTONLeading Pure Water AnalyticsUltrapure Water Quality AssuranceSelf-calibrating Silica AnalyzerTrace levels of silica in ultrapure water can cause spot formation duringwafer drying. Ensuring silica removal in UPW production is vital. The new2800Si Silica Analyzer not only detects contamination quickly, the unitcalibrates itself automatically, saving valuable operator time.The importance of minimizingsilica in UPWWater spots on silicon wafers can lead toreduced film adhesion, contact resistance,and other problems. The presence of silicain ultrapure water is largely responsible forwater spot formation. Silica dissolutionduring rinsing steps can add to the silicacontent in process baths, aggravating theproblem. Therefore, it is important thatthe silica content of ultrapure water isminimized and any increase in levels isquickly identified.operating treatment systems. Silica hasnegligible conductivity and thereforecannot be detected using resistivitymeasurements.Silica is in all water supplies and requiresmembrane separation and/ or ion exchange for its removal. Direct, continuoussilica measurement is the most effectivemeans to protect against contaminationfrom spent anion resin and improperlyEarly detection of trace contamination isavailable with minimal operator supervision. The 2800Si Analyzer enables unattended automatic calibration at a userconfigured interval.Optimized design meets silicameasurement challengesThe METTLER TOLEDO Thornton 2800SiSilica Analyzer is a reliable on-line instrument designed specifically for pure watertreatment. The analyzer provides assurance of water purity to optimize ion exchange production of ultrapure water.
ApplicationsUltrapure water monitoring at ppb silicalevels can ensure the highest quality wateris being delivered. According to the ITRSRoadmap, total silica should be 0.3 ppb.With the 2800Si, silica breakthrough ofpolisher anion resin is detected at very lowppb levels and contaminated water can bediverted before it reaches critical areas.Features and benefitsj Automatic, unattended calibration –provides excellent repeatability andsaves operator timej Automatic zeroing with every mea-surement – ensures measurementstabilityj Simultaneous display of silica andmeasurement timing – provides convenient analyzer status at a glance,saving operator timej Analog output with choice of scaling –enables easy integration into data acquisition systemj Full enclosure – safely protects reagent containers and components inplant environmentj Large reagent containers enable along service interval – reduced maintenance timeAutomatic calibration minimizesoperator interventionThe 2800Si performs a zero calibrationbefore each measurement cycle. An automatic span calibration is performed atscheduled intervals (monthly is typical)using a known silica concentration standard. The calibration cycle may also beinitiated manually.Fully protected from plantenvironmentThe analyzer is provided with a full dustand drip resistant lockable enclosure thatprotects the reagents and measurementcomponents from the plant environment.For more information visit:c www.mt.com/Thornton-silicaPublisher / ProductionMettler-Toledo AGProcess AnalyticsIm Hackacker 15CH-8902 UrdorfSwitzerlandIllustrationsMettler-Toledo AGWolandmaster Dreamstime.comPuretec Industrial WaterFreezingtime, Plendl iStockphoto.comSubject to technical changes. Mettler-Toledo AG 01/13.Printed in Switzerland.2METTLER TOLEDOMicroelectronics News 62800 SiSilica Analyzer
Conductivity SensorsHigh-performance Sensors for CEDI TechnologyWater Systems Provider Relies on ThorntonWater quality can be determined with conductivity measurements, butrequires very accurate sensors. When Pure Water Group produces watersystems for its customers, it relies on Thornton sensors and transmittersto provide reliable conductivity measurements for demandingapplications.Dutch producer of water systemsThe Netherlands-based Pure Water Groupproduces components and systems for theproduction of diverse water qualities inpower and petrochemical plants, solarenergy, microelectronics fabrication, andpharmaceutical production. Water purification technologies include reverse osmosis (RO), ultrafiltration, and continuouselectrodeionization (CEDI). The companyserves customers located in Europe, Africa, the Middle East, and Russia, andships approximately 30 systems annuallywith capacities ranging from 20 to over1,000 cubic meters per hour (88 to over4,400 GPM).CEDI technology with reverseosmosisPure Water Group Technologies divisionspecializes in water systems incorporatingSiemens Ionpure CEDI technology for awide range of applications. CEDI technology is an environmentally friendly operation and provides continuous waterproduction. The process uses electricity incombination with ion exchange membranes and resin to separate dissolved ionsfrom water. The resin in the modules doesnot exhaust because it is continuouslyregenerated by an electric current.A CEDI system purifies RO product waterto constant quality ultrapure water. During this process most of the remainingions are removed from the product water,including weakly ionized materials suchas silicates and CO2. CEDI direct-currenttechnology advantages include:j No need for regeneration chemicals,therefore there is no hazardous chemical waste to dispose ofj Continuous production of pure waterand continuous electrical regenerationinstead of periodic shutdowns forchemical regenerationj More compact than traditional ion exchange plants by eliminating the entire regeneration system and chemicalstorage facilityConverted to ThorntoninstrumentsPure Water Group’s customers had beenexperiencing accuracy problems withprevious instrumentation installed on itspure water systems. Conductivity accuracyMETTLER TOLEDOMicroelectronics News 63
is particularly important in order to provethe water is within customer specificationand process requirements.18.2 MΩ cm resistivity.” Each systemtypically uses three sensors coupled withThornton M300 transmitters.We have experienced no call-backs fromour customers in the most demandingwater quality applications.”According to Pure Water Group projectengineer Frank Scheepers, “We were looking for a more reliable conductivity measurement system to replace existingcomponents. The supplier of our CEDImodules recommended Thornton measurement systems, and we have foundthem to be consistently reliable and accurate in a range of applications toWith the introduction of the M800 multiparameter, touch-screen transmitter PureWater Group is considering upgrading,allowing up to four sensors to be connected to a single transmitter, thus savingpanel space and parts inventory.Find out more at:c www.mt.com/ThorntonconductivityIonpure is a trademark of Siemens its subsidiaries or affiliates.Mr. Scheepers adds, “Thornton measurement systems perform consistently well.Simple Conductivity Sensor CalibrationCalibrator Helps Ensure AccuracyUniCond conductivity sensors have a very wide measurement range – from seawaterto ultrapure water – making the same model of sensor suitable for a broad variety ofConductivity Sensor Calibratorapplications. Now, UniCond has been improved further with a tool that allows calibration4METTLER TOLEDOwithout removing the sensor from the process.Why is accuracy important?Semiconductor manufacturers constantlystrive for higher product yields and lowermanufacturing costs if they are to remaincompetitive in today’s market. Since waterpurity affects product yields, the need forreliable and accurate purity measurements is increasing. Resistivity (and itsreciprocal, conductivity) is one of the bestmethods of detecting ionic contaminationin a UPW water system. As a result, a sensor’s ability to repetitively and accuratelydetect ultra-low levels of ionic contamination is critical in semiconductor manufacture. Ultrapure water has a resistivity ofMicroelectronics News 618.18 MΩ cm at 25 C; therefore, resistivity instruments must have the ability toaccurately and repeatedly detect verysmall conductivity changes on a nonzerobackground.Calibration optionsThe ability of UPW systems to producewater with lower ionic concentrations andthe demand to reduce costs has benefitedfrom the introduction of a new generationof resistivity instruments. Today’s digitalsensors and transmitters are more accurate, have more inputs and outputs, areeasier to operate, and control more of thewater system than ever before. TheMETTLER TOLEDO Thornton UniCondsensor measures an expanded range from0.50 k Ω cm to 18.18 MΩ cm (conductivity 0.02 – 50,000 µS / cm) with up to33 % higher accuracy than analog sensors.To supplement this, a unique calibrationmodule provides simplified calibrationwithout removing the resistivity sensorfrom the process.Simple to use calibratorCalibration practice in most fabs requiresat least annual calibration of resistivitysensors and often the measuring circuit as
well. With conventional sensors and instruments, the measuring circuit must becalibrated against a series of precisionresistors covering the range of measurement. METTLER TOLEDO Thornton hasprovided calibration modules containingall of these resistances, conveniently packaged and with traceable, certifiedaccuracy.With new digital UniCond sensors, themeasuring circuit is built into the sensorand calibration of the measuring circuitis also performed on the sensor. The procedure, and UniCond Calibrator withswitch-selectable precision resistors, supports this capability, with readout of results at the transmitter. In fact, the mea-suring system even allows calibration ofthe electronics with the sensor still immersed in the water loop.Once the measuring circuits for resistivityand temperature are calibrated, then thecomplete sensor, including cell constantand temperature sensor, are calibratedbased on a standard conductivity solutionor by comparison with a certified referenceinstrument measuring the same sample.The temperature is calibrated by comparison with a standard temperaturedevice.Alternatively, the sensor may be returnedto the factory for complete recalibrationand certification. This is a common prac-tice, at least for standard sensors. Thehigher accuracy of the UniCond sensor ispreserved because the same built-in measuring circuit used during factory calibration is used after installation, i.e. factorycalibration accuracy equals installed accuracy. This is unlike conventional sensors where the measuring circuit in thefactory stays in the factory and the sensoris installed with a different instrumentand different signal cable length on site.UniCond sensors provide a definite step upin performance compared with previousgenerations of conductivity sensors.For more information go to:c www.mt.com/unicondThe Calibrator allows calibration of a UniCondsensor while it is in the process.METTLER TOLEDOMicroelectronics News 65
TransmittersThornton is “the Preferred” ChoiceIn Mobile and Standalone Water SystemsThe tough environmental conditions in the southwestern United Statesare demanding on mobile water trailers. For Puretec Industrial Water,the performance of Thornton instrumentation in this location is a testamentto their durability and reliability.Independent water purificationcompanyPuretec Industrial Water is an independently-owned, fourth-generation familybusiness serving customers in the southwestern United States, an arid region withsome of the strictest water use and qualitystandards in the world.Puretec dates to 1965, when Mr. Jim Harrisstarted an industrial division of his father’s and grandfather’s water business.They were originally franchisees of Culligan water softening, a service that removes minerals to improve the cleaningproperties and taste of residential tapwater. Now run by father and son Jim andJed Harris, Puretec employs 90 staff and isgrowing at the rate of about 15 % each year.The company’s water and desalinationsystems incorporate reverse osmosis, ultraviolet sterilization, microfiltration,TOC reduction and mobile trailers foron-site water purification in the microelectronics, power generation, pharmaceutical, and food and beverage industries.Systems meet demandingmicroelectronics industryrequirementsPuretec provides high purity water systemsfor the microelectronics industry to meetdemanding production requirements. Theultrapure water from Puretec systems isused for washing and rinsing semiconductor components during manufacture,cleaning and etching operations, and asthe source for ultrapure steam for oxidation of silicon surfaces.Water systems are designed to maintain areliable flow of water at 18.2 MΩ-cm withcolloidal, organic and ionic impuritiesreduced to the low part per trillion (ppt)range. The company also offers reverseosmosis membrane cleaning services tooptimize performance in generating ultrapure water.Thornton – “the preferred” waterquality instrumentsAccording to general manager Jed Harris,Puretec customers are diverse and demanddependable, quality construction in theirwater systems. Water delivered to customers systems must often attain 18.2 MΩ cmresistivity. Instruments must function reliably, accurately, and be easy to calibrate.6METTLER TOLEDOMicroelectronics News 6
“Thornton instruments work well,” commented Mr. Harris. “We usually insist oninstalling Thornton sensors and transmitters in our customers’ water systems.”Thornton M300 transmitters are used inPuretec’s mobile water trailers and incustomer installations, monitoring dozens of data points in the water system.Operation in mobile trailer watertreatment systems is a testament to thedurability and reliability of Thornton instrumentation which travels thousands ofmiles throughout the lifetime of a systemover rough roads between the ultrapurewater user and the Puretec service facility.Despite this rough handling, Thorntoninstruments provide accurate measure-ments to confirm water quality within userrequirements.Richard Mays, electrical design engineer,reports that with strict discharge standardsin California, reclaiming and reusingwater appropriately are key factors insystem design. “Puretec systems monitorpH, conductivity, TOC, sodium, and anumber of other parameters depending onour customers’ requirements. Our watersystems are used in demanding environments, and the instruments must be builtto perform accurately and reliably underthese conditions. It’s vital to use productswe can rely on, and that our customersfind convenient to use. We have confidencein Thornton.”Puretec is currently installing the newThornton M800 ISM multi-parameterdigital transmitter with touchscreen andunique iMonitor predictive sensor diagnostics capability. Mr. Mays reported thatcustomers who have used the newmulti-parameter transmitter are pleasedwith its user-friendly operation and abilityto monitor multiple parameterssimultaneously.Puretec contributes to improvethe communityOwners of Puretec support charitablefoundations to enhance quality of life inother countries. A portion of their operating profit goes towards aiding the GlobalWater Foundation to develops wells andwater sources for underserved regions inCentral America.To learn more visit:c www.GlobalWater.orgc www.mt.com/pro-microPuretec service technician Tim Dowds inspects instrumentation on a water system controlpanel in its Oxnard, California facility.METTLER TOLEDOMicroelectronics News 67
Dissolved OzoneOzone Control and MeasurementIn Microelectronics ProductionOzone is recognized as an excellent agent for disinfecting UPW systems. Its strong oxidizingpotential destroys organics and is utilized for functional waters in wafer cleaning tools. TheIntelligent Sensor Management ozone sensor from Thornton provides rapid, accurate responseto ozone concentrations, and also offers excellent sensitivity to zero levels of ozone.Ozone is an effective sanitizingagent for UPWOzone has many benefits as a sanitizer.There are no byproducts generated as withother chemical sanitizing agents, andresidual dissolved ozone rapidly breaksdown to oxygen in water. However, ozonegenerating equipment is both a capitaland operational investment and efficientoperation is key to realizing a positivereturn on investment. To accomplish effective ozone operation requires the use ofa stable and reliable dissolved ozone measurement system and pH control of theultrapure water.The use of dissolved ozone in UPW systemsis commonplace in semiconductor facilities around the world. Ozone is aneconomical and practical approach tocontrolling and preventing microbialcontamination, and to reduce organiclevels in UPW. As many plants operatearound the clock, year round, the instrumentation used to monitor ozone must bereliable, robust, and low maintenance.The dual use of ozone insemiconductor facilitiesThe first use of ozone in the semiconductor manufacturing process is for produc-tion of functional waters. Wafer processingrequires the use of functional waters for avariety of wet cleaning processes. Functional waters begin with UPW, followed bythe addition of a specific gas and / orchemical which can be used combinedwith physical energy (e.g. ultrasonic) toenhance the cleaning potential. There arethree types of functional water: ozonatedUPW, hydrogenated UPW, and electrolyzed(ion) water:1. Ozonated water is used for organic removal (pre-cleaning, pre-depositioncleaning, post-deposition cleaning,photoresist strip)2. Hydrogenated water for particle removal (rinse after etching)3. Electrolyzed water for removal of metaland particlesOzonated ultrapure water is used in thesemiconductor manufacturing process forcleaning and stripping of wafers due to thestrong oxidation potential of ozone. Control of dissolved ozone is critical to ensureproper concentration for the wafer cleaning process. Ozone concentration and thehalf-life of ozone are dependent on temperature and the pH of the ultrapure waterused to produce functional water, andthereby enhance removal of impurities.The pH is lowered to a value of 4 to 5(controlled with NH3 gas addition) foroptimal operating conditions for removalof copper (Cu) from the wafer. To ensureeffective oxidation of the organics, resis-8METTLER TOLEDOMicroelectronics News 6
tivity is measured and monitored duringthe process. Additional monitoring of theprocess with total organic carbon (TOC)sensors is performed to verify removal oforganics and prevent bacterial growth.Customer case studyThe control, monitoring, and maintenance of the UPW system at a producer ofintegrated circuits and embedded semiconductors is a daily challenge. Ourcustomer’s facility produces microcontrollers and embedded flash memories forglobal markets and is in the process offacility modifications to accommodate300 mm wafers and 22 nm linewidthcircuits.Dissolved ozonesensorAn efficient andcontrolled ozonesystem is criticalto operationsThe second use of ozone isas a sanitizer for ultrapurewater. Our customer’s microelectronics facility usesperiodic ozonation to ensure the UPW distributionloop is free from bacteriaand to reduce organics inthe water.A Thornton Ozone Sensormeasures the ozone outputlevel and allows the UPWplant operator to adjust, ortune, the ozone generatingsystem output to ensure an effective oxidation level.Although there are many steps in the waterpurification process, bacterial and microorganism contaminants often exist indistribution loops. Water loops such as theone in this facility transport large volumesof ultrapure water in polymer pipe comprised of multiple connection fittings,sample points, and sensor installationlocations. If not routinely cleaned, thesecan contribute to increasing contamination levels.Ozone sensor designed to meetcustomer requirementsThe Thornton Ozone Sensor providesrapid, accurate response to ozone concentrations. In addition, it also offers excellent sensitivity to a zero value to ensuredestruction of ozone before distribution ofthe wa
METTLER TOLEDO Microelectronics News 6 3 Conductivity Sensors CEDI technology with reverse osmosis Pure Water Group Technologies division specializes in water systems incorporating Siemens Ionpure CEDI technology for a wide range of applications. CEDI technol-ogy is an environmentally frie
Commercial Off-The-Shelf (COTS)Reliability Concerns for COTS Microelectronics in Space & Military Applications Author: Mike Sandor, Shri Agarwal Subject: COTS Microelectronics Keywords: Commercial Off-The-Shelf, COTS, Reliability Concerns, Microelectronics, Space Application
MICROELECTRONICS. Next generation microelectronics require increased performance and integration, advanced chip technology and miniaturization. Samtec’s extensive microelectronics and high-speed interconnect expertis
Fundamentals and Applications of Vacuum Microelectronics Zhuowen Sun EE 698A. Outline Introduction Field emission basics Spindt emitters and arrays . Vacuum Microelectronics, John Wiley & Sons, 2001 [4
Trusted Microelectronics Joint Working Group Team 1 White Paper I. FOREWORD Over the course of the past 70 years, the United States Government (USG) microelectronics needs for national security applications [D
microelectronics applications on information systems. This change is reflected by the addition ot ISA.to tne WoTShop n ld was prompted by the evolution of heterostructure microelectronics witnessd over Ae p!evtousPeveTand the fart that the heterostructure issues we address are no longer
Low Power Microelectronics: Retrospect and Prospect JAMES D. MEINDL, FELLOW, IEEE The era of low power microelectronics began with the invention of the transistor in the late 1940’s and came of age with the inven- tion of the integrated circuit in the late 1950’s. Historically, the most demanding applications
In International Symposium on Microelectronics (Vol. 2010, No. 1, pp. 000474-000478). International Microelectronics Assembly and Packaging Society. [2] Zhong, Z. W. (2008). Wire bonding using insulated wire and new challenges in wire bonding. Microelectronics In-ternational. [3] Evans Jr, D. D. (2013, January). Multipurpose Wire Bonding .
OF ARCHAEOLOGICAL ILLUSTRATORS & SURVEYORS LSS OCCASIONAL PAPER No. 3 AAI&S TECHNICAL PAPER No. 9 1988. THE ILLUSTRATION OF LITHIC ARTEFACTS: A GUIDE TO DRAWING STONE TOOLS FOR SPECIALIST REPORTS by Hazel Martingell and Alan Saville ASSOCIATION OF ARCHAEOLOGICAL ILLUSTRATORS & SURVEYORS THE LITHIC STUDIES SOCIETY NORTHAMPTON 1988 ISBN 0 9513246 0 8 ISSN 0950-9208. 1 Introduction This booklet .
