Gregory H. Leggett & Edwin K. Arrant, Millipore, Allen, TX, USA

ABSTRACT

Slight changes in operating conditions of Mass Flow Controllers can have subtle but profound effects on production schedules. Constant monitoring and integration into the Fab network system for device management can lead to significant advantages. The monitoring requirements are examined and the use of intelligent sensors, their integration and the effect on networking operational efficiency are discussed. 

Joanne Schroeder & Glenn Mayer, P.E., EDSG - Environmental Data Solutions Group, CA, USA; Randolph Brummett, Brummett & Associates, Newport Beach, CA, USA

High technology, semiconductor industries are viewed as clean, environmentally friendly industries by the public and investors. Proactive and safe environmental, health and safety (EHS) practices should be communicated to stakeholders to promote high stock valuations and enhance public perception and image. An environmental management information system (EMIS) can provide numerous advantages that specifically address the unique needs of semiconductor manufacturers.  

R. Torres, D. Fraenkel, J. Vininski, E. Hennig, T. Watanabe, & V. Houlding, Matheson Gas Products, Longmont, CO, USA

Purification of high-pressure corrosive gases has traditionally utilised a pressure regulator prior to introduction into the purifier. However, reported regulator failures have been shown to be a major disadvantage of using this conventional configuration. Such failures are a great concern owing to the damage they may cause to downstream components such as pressure transducers, mass flow controllers, and on-line monitors. A high-pressure source gas purifier installed before the regulator offers a solution to this common problem. Recently, a new purifier for corrosive gases has been developed that can be used up to full cylinder pressure for source gas purification.

Sowmya Krishnan & Mohamed Saleem, Ultra Clean Technology, Menlo Park, CA, USA

ABSTRACT

Gas delivery systems transporting corrosive and reactive gases could potentially compromise the purity of the gases. Currently, gas delivery tubing and components are made of electropolished (EP) stainless steel. Welds and heat-affected zones of EP stainless steel undergo severe corrosion when halogen-based gases are transported. Chromium-rich oxide passivation (CrP) of stainless steel can successfully counter these corrosive effects. Two case studies comparing EP and CrP stainless steel are presented. Additionally, an analysis is presented of cost-of-ownership issues associated with CrP systems.

Semiconductor processing in the next few years will employ several new materials. This poses chemical and risk management challenges. In this article the regulatory environment in the United States is described. Some engineering solutions are discussed. An effective strategy uses both risk management tools and engineering solutions. 

Wolfgang J. Sievert, Riedel-de Haën GmbH, Seelze, Germany

ABSTRACT

The role of Europe in the world semiconductor market is becoming increasingly important. This article looks at the markets for chemicals used in wet processing in semiconductor manufacturing. The changing quality requirements for chemicals are examined. The JESSI project, described here, speeded up the implementation of the XLSI quality level. The challenges facing chemical manufacturers today are described. 

Ashutosh Misra, Air Liquide Electronics Chemicals & Services,Inc., Dallas, TX, USA
Hervé Dulphy & Eric Duchateau, Air Liquide Electronics, Labielle, S.A., Pont De Claix, France

ABSTRACT 

Conventional methods of qualifying liquid chemical distribution systems utilize expensive process chemicals which are not always efficient in leaching out metallic contamination. This impacts both the cost and the time associated with a qualification process. We propose a new method of accelerated cleanup of PFA distribution systems using high purity dilute hydrofluoric acid and deionized water. This procedure was first characterized in lab scale experiments where it demonstrated superior metal leaching ability as well as subsequent rinsing of all fluoride from the system using a combination of static and dynamic leach/rinse cycles. Such a procedure results in significant reduction in qualification time, costs and waste generation. The proposed method was subsequently implemented on a full scale commercial liquid chemical distribution system at a semiconductor manufacturing facility. 

Ashutosh Misra & Bud L. Schmidt, Air Liquide Electronics Chemicals & Services, Inc., Dallas, TX, USA; Lindsey Hall, Jennifer Sees & Trace Q. Hurd, Texas Instruments, Inc., Dallas, TX, USA

The detrimental impact of metallic impurities on device reliability and yield has been established in several previous studies [1-6]. It is also known that roughening of the silicon surface as a result of contamination with light metals such as calcium can result in degradation of the gate oxide integrity (GOI) [7-10]. While many investigations of calcium adsorption from process chemicals such as SC1 and SC2 have been carried out to date [11-15], the phenomenon of calcium adsorption on silicon and silicon oxide surfaces from deionized water is not clearly understood. Mouche et al. [13] concluded in their study that the amount of calcium adsorbing on silicon oxide surfaces from deionized water is higher than in SC1 solution, and that such adsorption reaches a plateau in surface concentration above 2 ppb in solution. A similar phenomenon was observed for copper and aluminium deposition from deionized water in their study. In a recent study, Loewenstein and Mertens [16] have observed that calcium contamination on silicon oxide surfaces can be reduced substantially by reducing the pH of the medium. It is generally believed that calcium adsorption from DI water proceeds by the attraction of Ca2+ ions to the negatively charged silicon oxide surface and subsequent reaction with the Si-OH functions, giving rise to deposits [13].

Dr. Steve Allen and Dr. Michael R. Hahn, Microbar Incorporated, Sunnyvale, CA, USA

ABSTRACT 

Modern semiconductor fabs are highly dependent upon a continuous flow of ultra-pure water for normal operations. Large fabs measure their water usage in millions of gallons per day. The cost of producing this water, both in capital expenditures and community goodwill, is continually rising as world-wide fab capacity is expanded. Most of the current water consumption is for processes such as CMP, wet etch, wafer cleaning and back grind. The wide disparities in pH, dissolved and suspended solids content, and metallic contamination present major challenges for facilities trying to treat wastewater.

Cliff Fields, Newark, CA, USA

ABSTRACT 

Process engineers have frequently overspecified systems and equipment. The driving philosophy is to go for the best possible. This is a highly expensive line to pursue and equipment manufacturers have responded with ever more complex and expensive manufacturing systems. The author proposes an alternative approach to the selection of equipment which should have positive advantages for the cost conscious production engineer.