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Our consultants regularly engage in research activities related to our normal client services. This archive includes the majority of the published technical papers, presentations, and other publications related to this research.

Case Study – Vibration Source Investigation in Large Semiconductor Fab Facility

    ABSTRACT Semiconductor fabrication facilities contain many vibration sensitive instruments which are often in close proximity to large vibration sources. A good structural system and proper vibration isolation of mechanical equipment is required to minimize the impact from sources such as pumps, fans, piping, and ducts within the building. This paper presents a case […]...
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Construction vibration monitoring for sensitive facilities

Building expansion and densely developed campuses often require construction adjacent to highly vibration sensitive facilities such as advanced technology manufacturing, laboratories, and hospitals. The vibration generated by the construction work poses a considerable risk to the sensitive processes in these facilities, which typically need to continue operations during construction. In these scenarios it is often […]...
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Control of infrasonic noise from mechanical ventilation systems in sensitive imaging laboratories

High resolution imaging equipment, such as transmission and scanning electron microscopes, can be very sensitive to the environment in which they are installed.  Environmental factors including temperature, electromagnetic interference, vibration, and noise must be considered in the design of laboratories intended to house such instruments.  With regard to noise, this equipment is often most sensitive […]...
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Temperature and Frequency Effects on Properties of Polymer-Modified Concrete

The dynamic elastic modulus and damping of concrete made from ordinary portland cement (OPC) remain relatively constant over the significant ranges of temperatures and frequencies that might be encountered in normal application.  However, this is not the case with polymer-modified concrete (PMC).  This paper presents results of an experimental study examining the role of temperature […]...
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Dynamic Stiffness and Subgrade Modulus of a Slab-on-Ground

“Conventional wisdom” amongst users of cutting-edge electron microscopes and other sensitive research instruments is that their instrument will perform better if supported on a “thick” concrete slab-on-ground.  Typically, their choice of a slab thickness is based on what worked well for someone else, without any thought given to an analytical justification.  The paper presents the […]...
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Vibrations: Measured performance of newly designed and built nanoscale research facilities

The presentation examines how different structural designs and isolation schemes impact vibration characteristics of space in advanced technology facilities.  Vibration data measured in completed facilities successfully working at the nanometer scale are used to explore the manner in which vibration criteria of “better than VC-E or NIST-A” can be achieved.  Data from 23 different schemes […]...
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Acoustics: The impact of low-frequency sound (infrasound) on imaging equipment in nanoscale research

The presentation reviews issues associated with low frequency sound—sources, human perception, typical levels, and effects on imaging systems.  A set of infrasound criteria are presented which correlate imaging resolution with low frequency sound levels.  Design features intended to mitigate infrasound generation and impact are discussed. M. Gendreau, "Acoustics: The impact of low-frequency sound (infrasound) on […]...
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Effects of frequency and depth on attenuation of ambient ground vibration.

This article discusses the effects of below-grade building placement on vibrations measured prior to design and construction. Typically, site vibration studies are conducted on undeveloped locations (grass fields, parking lots, etc.) to assess the ambient vibration conditions for a potential building site. These results, though very important, do not necessarily represent the final ambient vibration […]...
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Solution of noise transmission problems by in situ segregation of composite transmission factors of complex partitions using sound intensity

In order to make the best decisions for reducing noise transmission through a complex partition, it is necessary to differentiate and determine the relative contribution of the partition elements to the transmitted noise. A “complex partition” is here defined as a partition with multiple elements in the plane perpendicular to the impinging noise, such as […]...
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Voids Beneath Slabs-on-Ground: Using the impulse response test to verify adequate slab support

Introduction A concrete slab-on-ground is one of the most common of all floor types.  Slabs-on-ground are popular for many applications, especially in research facilities, where they usually provide the highest-quality vibration environment.  This is because they are stiff and uniformly supported, such that they do not exhibit the resonance characteristics of a suspended slab. As […]...
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Vibration sensitivity of optical microscopes in the healthcare setting

The paper examines vibration criteria for benchtop and articulated floor-supported optical microscopes, comparing published specifications with data measured in hospitals for diagnostic purposes.  A case study of vibrations that degraded orthopedic microsurgery is of particular interest.  Revisions and enhancements of published criteria are proposed. H. Amick and M. Gendreau, “Vibration sensitivity of optical microscopes in […]...
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The Effect of Varying Acoustic Pressure on Vibration Isolation Platforms Supported on Air Springs

Air spring isolation systems are commonly used to support sources of vibration, or equipment sensitive to vibration, in order to reduce vibration transmission from source to receiver. In the latter case, commercial isolation tables or custom-designed “plinths” may use isolation systems to provide reduced vibration environments at the base of sensitive equipment supported on them. […]...
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Long-span truss structures for low-vibration environments

Historically, waffle slabs have been widely used in the process floor design in semiconductor production facilities.  In a less stringent vibration environment, concrete joist slab with stiffeners could be a suitable design option. In both of the two approaches, the effectiveness of vibration control in floor structures would be substantially reduced when the column span […]...
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Mode Selection for Footfall Analysis of Floors

Floor vibration due to footfall is of great importance in the design of buildings for vibration-sensitive research and production. The bulk of the predictive modeling methods for footfall involve the use of the “fundamental” resonance frequency which would be excited by the walker. In a complex structure, the analyst may be presented with a choice […]...
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Mechanical and Footfall Vibration Impact to Healthcare Facilities: Criteria and Design Strategies based on Research and Case Studies

The authors present a review of current healthcare facility vibration criteria: Process of selecting criteria Process of selecting design parameters Case Study: Surgical microscope and its criteria Summary of criteria we use   M. Gendreau and H. Amick, “Mechanical and Footfall Vibration Impact to Healthcare Facilities: Criteria and Design Strategies based on Research and Case […]...
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Generic Noise Criterion Curves for Sensitive Equipment

ABSTRACT Electron beam-based instruments, and other high-resolution instruments, are sensitive to the environment in which they operate. Adverse environments may limit achievable resolution. Equipment manufacturers provide specifications defining acceptable amplitudes of various environmental contaminants, such as vibration, electro-magnetic energies, and acoustic noise. However, the quality of these specifications varies significantly, from well-defined to conjectural. Additionally, […]...
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Vibration Kills’ and Other Lessons from the Trenches

In many areas of acoustics and vibration control, criteria are based upon parameters such as comfort, privacy, intelligibility, productivity, or machine precision.  One can approach these criteria with a somewhat dispassionate attitude.  However, when working with the biological research communities, one is periodically reminded by the researchers and medical practitioners that much of their work […]...
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Ground Motion Studies at NSLS II

In this study, an array of vibration measurements at the undisturbed NSLS II site has been performed in order to establish the “green-field” vibration environment and its spectral characteristics. The interaction of the green-field vibration environment with the NSLS II accelerator structure and the quantification of the storage ring vibration, both in terms of amplitude […]...
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The Effect of Buildings on Ground Vibration Propagation

This paper discusses the effects of buildings on ground vibration propagation. Typically, site vibration studies are conducted on undeveloped locations (grass fields, parking lots, etc.) to assess the ambient vibration conditions for a potential building site. These results, though very important, do not necessarily represent the final ambient vibration conditions that would be observed in […]...
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Visually Observable Vibration Sensitivity of a Laboratory Bench Microscope

[1] ABSTRACT Bench-mounted optical microscopes have a wide variety of applications in science and technology. The vibration sensitivity is a function of magnification, vibration direction and support conditions. The paper presents the results of experimental studies addressing vibration sensitivity as well as the amplification and attenuation provided by typical laboratory casework. The benchtop vibration amplitudes […]...
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Vibration Sensitivity of a Laboratory Bench Microscope

Bench-mounted optical microscopes have a wide variety of applications in science and technology.  The vibration sensitivity is a function of magnification, vibration direction and support conditions.  The paper presents the results of experimental studies addressing vibration sensitivity as well as the amplification and attenuation provided by typical laboratory casework.  The benchtop vibration amplitudes at which […]...
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Nanotech I: Site Parameters and Nanotech II: Case Studies and Trends

The first important steps for planning nanotechnology facilities include site and facility assessment to see if the nanotechnology can be performed on the site.  “One site does not fit all” might be a good way to approach planning for nanotechnology.  The research carried out in these facilities is highly sensitive to excessive vibration, noise, electromagnetic […]...
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Experimental Determination of Modal Damping in Concrete Beams

An approach using experimental modal analysis (EMA) is presented for measuring the material damping properties of concrete beams.  This approach, now popular in mechanical and aerospace engineering, uses hammerblow excitation and frequency-domain analysis to estimate resonance frequencies and modal damping.  Damping properties quantified in this manner are compared to results obtained by traditional methods, which […]...
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Site Investigation Criteria for Nanotech Labs

The first important steps for planning nanotechnology facilities include site and facility assessment to see if the nanotechnology can be performed on the site.  “One site does not fit all” might be a good way to approach planning for nanotechnology.  The research carried out in these facilities is highly sensitive to excessive vibration, noise, electromagnetic […]...
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Reducing Floor Vibrations: A polymer admixture provides increased damping in concrete

This “product note” in a trade publication discusses a polymer admixture designed to increase concrete’s damping properties and therefore increase the decay of impact-induced vibrations. The liquid additive is similar to styrene-butadiene rubber (SBR) admixtures that are commonly used in pavement to improve durability, but has been modified by adding vegetable gum in the suspension.  […]...
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Buildings for nanotechnology: A look back at the genesis of a new building type

Nanotechnology research is the newest entry into the dynamic field of advanced technology. The buildings required to carry out this work may be dramatically different from those used for other areas of advanced technology. Virtually all of these facilities impose stringent environmental criteria upon the workplace, in such areas as vibration, temperature control, fume exhaust, […]...
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Centile Spectra, Measurement Times, and Statistics of Ground Vibration

Facilities for advanced technology—particularly nanotechnology—impose very stringent requirements on the quality of the site. Ambient ground vibrations are among the most critical factors to consider when selecting a site. Commonly-accepted vibration criteria are available and they, in turn, dictate many of the measurement parameters such as bandwidth, frequency range, etc. However, there are still many […]...
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Use of vibration criteria in the selection of building systems for nanoscale research facilities

Stringent vibration requirements must be met for laboratories housing sensitive equipment for nanotechnology research.  This paper provides guidance to the designer in the selection of structural systems to limit vibrations to acceptable levels.  Comments are also made on site selection, building planning issues, and cost-effectiveness solutions.  The concepts proposed are illustrated with examples of the […]...
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An experimental study of vibration attenuation performance of several on-grade slab configurations

There are several instances in the literature in which particular positions are taken regarding the nature of the floor supporting sensitive equipment such as advanced electron microscopes. Assertions are made that one methodology is better than another at reducing vibrations. However, very little experimental evidence has been provided to support those positions. This paper presents […]...
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Evolving criteria for research facilities: vibration

ABSTRACT The paper presents a review of generic vibration criteria used for vibration-sensitive technical facilities. The paper reviews the logic behind and evolution of the Vibration Criterion (VC) curves, originally known as the “BBN” criteria, and discusses the background of a generic criterion in common usage for nanotechnology, currently denoted NIST-A. The criteria are compared […]...
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Vibration and noise criteria used to evaluate environmental impacts of transportation projects on sensitive facilities

The paper examines the methodologies and evaluation criteria advocated by the U.S. Federal Transit Administration (FTA) and Federal Rail Administration (FRA) used to determine whether or not a proposed alignment for a transportation project adversely impacts affected land uses, such as research & development and high-technology manufacturing. The criteria in question are applied as limits […]...
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Addressing the environmental challenges of the NIST Advanced Measurement Laboratory

The recently built Advanced Measurement Laboratory at the National Institute of Standards and Technology (NIST) provides a great step forward for that organization with regard to its research environments. Vibration and temperature control were among the most critical concerns expressed by the researchers, and considerable attention was given to meeting their objectives. Critical laboratory environments […]...
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Can Vibration be Controlled with Concrete Damping?

Vibration has long been recognized as a contaminant in a fab. The vibrations can come from many sources both within and exterior to the facility. For quite some time, designers and consultants have discussed means by which future vibrations from “unplanned” sources might be mitigated via design or construction. This article presents one possible approach […]...
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Instalaciones para nantecnología

(In Spanish) This article explores nanotechnology from the perspective of a member of the advanced technology building design team—the structural dynamicist—and focuses on concrete, often the structural material of choice for these facilities. First, it shows how one application in nanotechnology led to research addressing some of concrete’s dynamic properties. Then it discusses some of […]...
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A “Toolbox” of Damping Treatments for Concrete Structures

The paper presents measures by which significant changes in the damping of concrete may be achieved.  A variety of alterations in mix design were examined experimentally, and the most effective treatments involved the use of polymer admixtures.  Significant changes in damping were associated with the use of several types of styrene-butadiene rubber (SBR) latex, ethyl-vinyl-acetate […]...
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Considerations regarding the appropriate timing for advanced technology facility vibration surveys

Vibration surveys are carried out for a variety of reasons over the lifetime of a facility for semiconductor fabrication (fab) or other advanced technology process.[1] Evaluations may take place as part of the site selection effort, during construction, or during the productive life of the facility. Generally, there should be a reason for a vibration […]...
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Maturation’ of the Vibration Environment in Advanced Technology Facilities

Abstract Semiconductor production and other advanced technology facilities are often designed in two stages, delineated as “base build” and “hook up”. The first stage, at completion termed “as-built” by ISO, includes the design and construction of the shell structure and all architectural, mechanical, electrical, and process systems needed to operate the building. The second stage, […]...
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Micro-Vibration and Noise

Noise and vibration are contaminants in semiconductor processing and research. Since the tools used in semiconductor manufacturing are sensitive to vibration and noise to varying degrees, excessive amounts of these contaminants can adversely impact yield, throughput, or the operating line width or resolution of the tools. In addition to the potential impact to tools, noise […]...
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Damping Properties of Polymer-Modified Concrete

The paper presents selected results from a broad study undertaken to explore means by which one might increase damping in concrete, which is relatively low—except for when the concrete is rather young—and essentially independent of temperature and frequency.  The most easily implemented approach involves the addition of latex admixtures to the concrete, resulting in a […]...
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Tool or Facility – What Should it Be? Reconciling Differences between Production Equipment Needs and Facility Support

It is not unusual for production equipment’s environmental requirements to be more stringent than the facility can economically provide, thus forming a “gap” between tool needs and facility capabilities, as shown in Fig. 1.  The gap can involve requirements for vibration, sound, EMI, cleanliness, or any of the many other environmental parameters.  This paper presents […]...
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Actual Vibration and Acoustics Measures on a Completed Nanotech Building — Duffield Hall

A case study, including vibration performance data, of one of the first buildings designed for nanoscale research. H. Amick, M. Gendreau and T. Xu, “Actual Vibration and Acoustics Measures on a Completed Nanotech Building — Duffield Hall,” invited presentation for the 2004 International Conference “Nanotechnology Research Space – The Next Step,” August 15-16, 2004, Ithaca, […]...
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Noise in Cleanrooms Served by Fan-Filter Units: Design Considerations

This paper is concerned with noise conditions in cleanrooms served by fan-filter units (FFUs), primarily of higher order clean class (ISO Class 1 through 5), although the concepts discussed also apply to rooms with higher particle counts (ISO Class 6 and higher). The need for frequent air changes to achieve the cleanliness goal is often […]...
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Construction of Nanotechnology Facilities

The sophisticated working environments required for nanotechnology facilities pose big challenges to their designers and constructors. Environmental requirements of a nanotechnology facility may include temperature and humidity control, air cleanliness, biohazard containment, limits on electromagnetic fields, special electrical power conditioning, and vibration and noise control. Most of these design aspects have evolved from the special […]...
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The Effects of Ground Vibrations on Nanotechnology Research Facilities

This paper examines the environmental requirements of nanotechnology from the perspective of a member of the advanced technology building design team, the vibration consultant.  It explores the variety of vibration environments required by different parts of the nanotechnology community, and how some of the more demanding of these environments are being provided.  A desirable vibration […]...
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Vibration Design of 300 mm Wafer Fabs

The semiconductor industry is experiencing the transition from 200mm to 300mm fabs. With a number of 300mm fabs now on-line, and many more in the construction and start-up stages, a discussion of 300mm fab design is pertinent. Vibration is an important concern in fab design and construction because many items of precision equipment (or “tools”) […]...
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Building Design for Advanced Technology Instruments Sensitive to Acoustical Noise

This is from the first of the BAT Workshops, and presents an overview of acoustics and noise control in the research setting. M. Gendreau, “Building Design for Advanced Technology Instruments Sensitive to Acoustical Noise,” Invited Seminar, presented at Buildings for Advanced Technology Workshop, National Institute of Standards and Technology, Gaithersburg MD, USA, 14 January 2003...
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Vibrations of Raised Access Floors

Raised access floors play a critical role in modern cleanroom design. They have unique mechanical properties that make them respond to dynamic loading in a manner quite different from conventional floors. For example, an unbraced floor is much more flexible horizontally than in the vertical direction. Horizontal vibration amplitudes with walker excitation may exceed 100 […]...
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Facility Vibration Issues for Nanotechnology Research

The paper presents an overview of the vibration requirements of nanotechnology facilities, drawn from both the semiconductor world and that of precision metrology. Structural approaches are discussed which are commonly used to meet some of the special vibration needs of these facilities. H. Amick, M. Gendreau, and C. G. Gordon, “Facility Vibration Issues for Nanotechnology […]...
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Meeting The Vibration Challenges Of Next-Generation Photolithography Tools

In the past, the vibration design process has been driven by the requirements for an acceptable ambient vibration environment for tools. However, the newest generation of photolithography tools, the "scanners" or "step-and-scan" systems, impose an additional requirement for the dynamic resistance properties of the tool's support points. This paper discusses the current scanner support criteria […]...
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Designing for Vibrations in the Laboratory

Many processes involved in advanced technology applications are highly sensitive to vibrations. Among these processes are precision metrology, high-energy physics, long-beam-path laser applications, biotechnology research, and the R&D and production of semiconductors. When designing facilities housing this equipment, considerable attention is spent on the mechanical and structural aspects. In most cases, vibration control measures add […]...
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Specification of the effects of acoustic noise on optical tools

Optical Tools respond to internal vibration that can be excited by the external acoustic environment. The degree to which this occurs depends on many factors, but primarily the correspondence between the resonance characteristics of the tool and the frequency content of the acoustic environment in which it operates. Adverse noise environments, such as those often […]...
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Effects of Distributed Source Coherence on the Response of Phased Acoustic Arrays

Phased acoustic arrays have been used successfully to locate propulsive and nonpropulsive aeroacoustic sources with the array located both in a moving wind-tunnel stream and in still air. Multiple or distributed sources may vary over the full range in coherence level, particularly when local reflections are present. A constant contour level integration boundary is defined […]...
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Effect of Surface Treatment on Array Microphone Self-noise

A method for reducing the flow-induced self-noise of acoustic array microphones was demonstrated in a wind tunnel. Unsteady boundary-layer flow in the wind tunnel induces large pressure fluctuations on exposed, flush-mounted microphone diaphragms, reducing the signal-to-noise capability of microphone arrays. Two important steps were take to reduce this background noise. First, the microphones were recessed […]...
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Construction Vibrations and Their Impact on Vibration-Sensitive Facilities

Abstract An approach is presented for performing site-specific assessment of the impact of construction vibrations on vibration-sensitive facilities. This requires expansion of existing methodologies such that frequency content is included. A case study is included. Introduction Many processes involved in advanced technology applications are highly sensitive to vibrations. Among these processes are precision metrology, high-energy […]...
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Pellicle-Induced Distortions in Advanced Optical Reticles

William H. Semke, Lowell K. Siewert, Andrew R. Mikkelson, Eric A. Risius, Ning Tang, Roxann L. Engestad, Edward G. Lovell, Jun-Fei Zheng, Dao Giang, "Pellicle-Induced Distortions in Advanced Optical Reticles," Proceedings of SPIE 20th Annual BACUS Symposium on Photomask Technology, Vol. 4186, pp. 207-216, Monterey, CA, 2000....
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Vibration Control Design of High Technology Facilities

High technology equipment such as that used for the production of advanced integrated circuits, for precision metrology, and for microbiological or optical research, requires environments with extremely limited vibrations. Ground motions, personnel activities, and the extensive support machinery typically present in high technology facilities may produce unacceptably severe vibrations, unless mitigation of these vibrations is […]...
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Environmental Noise Control for Semiconductor Manufacturing Facilities

This paper summarizes the authors' experience in modeling and controlling environmental noise from more than 30 semiconductor manufacturing plants ("wafer fabs") within the past six years. This type of facility typically has a large number of concentrated noise sources because of the unusually large amount of intake and circulation air required to maintain cleanroom conditions, […]...
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A Frequency-Dependent Soil Propagation Model

Vibration analyses of advanced technology facilities typically must consider frequency as well as amplitude of vibration. A soil propagation model is proposed which will allow the use of site-specific, measureable, frequency-dependent attenuation characteristics. A method is given which allows in-situ determination of those frequency-dependent properties. This approach is applied to the estimation of setback distances […]...
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Effects of Acoustic Noise on Optical Equipment

Optical tools respond to internal vibration that can be excited by the external acoustic environment. The degree to which this occurs depends on many factors, but primarily the correspondence between the resonance characteristics of the tool and the frequency content of the acoustic environment in which it operates. Adverse noise environments, such as those often […]...
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Generic Vibration Criteria for Vibration-Sensitive Equipment

The vibration criterion (VC) curves, commonly used in the design of facilities which house vibration-sensitive instruments and tools, were developed by the author and his colleagues, in the early 80's, published by SPIE in 1991 and by IEST in 1993. Each of the criterion curves A through E is associated with a "line width" or […]...
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Dynamic Characteristics of Structures Extracted from In-situ Testing

The paper discusses two primary areas of interest in a structural evaluation. First, in-situ measurements are used to confirm the predicted structural stiffnesses and resonance frequencies. Second, the evaluation characterizes the manner in which vibrations are propagated through the structure. Methodologies are presented for carrying out these measurements, and typical data are given. H. Amick, […]...
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Vibration issues in Facility Refurbishing

Vibration is a major source of contamination in any Fab facility and can have disastrous effects on plant output. When a Fabrication plant needs to be updated, the existing structure of the buildings may require extensive alteration to meet the new criteria of future operation. The sources of vibration both external and internal to the […]...
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Noise and Vibration Characteristics of Cleanroom Fan-Filter Units

Fan-filter units are an increasingly popular alternative to packaged air handlers and fan-tower recirculation air systems. They are used in mini-environments and general cleanrooms, especially in retrofit cleanrooms with limited height. This paper presents noise and vibration data measured on 8 fan-filter units. It also presents measurement methods and performance criteria for fan-filter units. Colin […]...
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Noise of Cleanroom Recirculation Air Systems

The commonly used recirculation air systems for microelectronics cleanrooms are described in this paper. The sound attenuation along the air flow paths are discussed along with noise control concerns. Also presented are the typical sound pressure levels measured in operating cleanrooms. Mei Q. Wu and Colin G. Gordon, "Noise of Cleanroom Recirculation Air Systems," (with […]...
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Vibration Data Representation for Advanced Technology Facilities

Vibration control in vibration-sensitive advanced technology facilities generally involves interaction between a vibration consultant and several other engineering disciplines. It is important that the other disciplines have a rudimentary understanding of the consultant's measurement methodologies and design approaches. Practitioners have developed a specialized analytical approach which shares some commonality with traditional civil engineering dynamics, but […]...
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Dynamics of Stiff Floors for Advanced Technology Facilities

Vibration control in vibration-sensitive advanced technology facilities generally involves design of a stiff floor for the vibration-sensitive area. The authors have found that the range of floor stiffness required for semiconductor facilities and laboratories falls on a continuum between "soft" and "stiff" floors. A significant variation in properties can be observed along this continuum. This […]...
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Dynamics of Advanced Technology Facilities: A Historical Perspective

The purpose of this paper is to set in perspective some of the issues involved in the dynamic of advanced technology facilities. By dynamics we mean vibration performance and vibration response. Through much of the paper, attention is focused on the microelectronics industry since vibration here is of critical importance and since this industry, more […]...
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Seismic Isolation of Semiconductor Production Facilities

Semiconductor facilities engaged in development, production, and mask-making for computer chips are extremely expensive, of which 3/4 might be the cost of the delicate equipment used to make the products (chips, masks, etc.). Much of this equipment is vibration-sensitive, and building designers go to great lengths to minimize the vibrations to which the equipment is […]...
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On Generic Vibration Criteria for Advanced Technology Facilities: with a Tutorial on Vibration Data Representation

Abstract The design of vibration-sensitive advanced technology facilities generally involves considerable attention to structural and mechanical aspects. In most cases, the vibration control measures contribute significantly to a facility’s cost. The selection of a vibration criterion for use in design is an important step in the design process. Many process equipment manufacturers have provided tool-specific […]...
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Active Vibration Control in Fabs

As device geometries go down, the need to isolate sensitive process tools from vibration increases. Building construction techniques and passive control methods can keep most of the vibrations under control, but low-frequency vibrations are still a problem. Adding active vibration control to the tool itself can cancel those problems. Kim, J. J., and H. Amick, […]...
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Vibration Control in Microelectronics Cleanrooms

In this tutorial we shall try to unravel some of the mysteries of cleanroom vibration: sources; methods of propagation; measurements; criteria and specifications; control and isolation.  The plan is to provide attendees with some of the tools necessary to understand the issues involved in vibration control.  Colin Gordon, “Vibration Control in Microelectronics Cleanrooms,” tutorial given […]...
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Analytical/Experimental Study of Vibration of a Room-Sized Airspring-Supported Slab

This paper reports the results of the finite element analysis and in-situ testing of a large-scale (4m x 10m) pneumatically isolated concrete slab. The slab was constructed as a design prototype for next-generation metrology laboratories at the National Institute of Standards and Technology (NIST) in Gaithersburg, MD. Data include computed and measured modeshapes and natural […]...
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Optimizing the Placement of a Road between Two Research Buildings – a Case Study

A problem arose during the design of major site renovations of a research campus that serves several research organizations. Prior to the site planning, two tenant organizations had progressed far into the design of new laboratory facilities. Each facility had a demonstrable sensitivity to vibration; unfortunately, there had been little coordination of the vibration requirements […]...
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Vibration Prediction and Control in Microelectronics Facilities

The importance of vibration in microelectronics production can be appreciated when one considers the extreme sensitivity of the "tools" and systems used in the chip fabrication process and the large amount of mechanical energy that is consumed in a modern cleanroom.  The great difference in the ratio of "power consumed" to "sensitivity" lies at the […]...
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NIST – Advanced Technology Laboratories: Metrology Laboratories & Vibration Control

The focus of this paper will be on laboratory design and issues related to vibration mitigation based upon the recent experience of Henningson, Durham & Richardson, Inc. (HDR) and its consultant, Acentech Incorporated, in designing new Advanced Technology Laboratories (ATLs) for the National Institute of Standards & Technology (NIST). Issues related to site selection, laboratory […]...
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Monitoring Of Vibration in Vibration-Sensitive Facilities

Vibration monitoring is a valuable tool in the operation of facilities which house vibration-sensitive equipment. Monitoring can detect trends in the vibration environment that may signal the need for remedial action before vibration-related problems are encountered. Monitoring is invaluable in situation where construction work is carried out within, or close to, the facility. The monitor […]...
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An investigation of dynamic soil-structure interaction as it relates to the design of foundation systems for microelectronics fabrication facilities

In recent years, vibration has become increasingly important as a factor to consider in the design of microelectronics fabrication facilities. As the demand for higher precision tools increases, the importance of vibration control also increases. In fact, at the present time, many aspects of structure/foundation design are controlled by vibration considerations rather than the traditional […]...
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A Review of Several Methods for Processing Vibration Data

For many areas of acoustics, standards organizations or regulatory bodies have mandated vibration or noise criteria and defined the appropriate processing methods. No such standards exist for vibration-sensitive facilities at this time except as defined by equipment manufacturers, facility owners, and/or vibration consultants. The existing criteria from these groups differ widely in form. This paper […]...
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Design of Stiff, Low-Vibration Floor Structures

Dynamic loading of a floor can excite vibrations that may adversely affect production or research activities using equipment supported on that floor. These loads may be caused by mechanical systems or personnel activities. One way to minimize vibrations is with a slab-on-grade floor, but often this is not possible due to constraints such as lot […]...
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The Influence of Bases and Benches on the Performance of Vibration-Sensitive Equipment

In most state-of-the-art microelectronics facilities, process equipment (tools), including vibration-sensitive equipment, is set on a structure to bring the equipment to the level of the raised access floor. Depending on their design these bases can amplify, through resonance, the vibration amplitudes that travel from the structural floor to the equipment base. Similarly, benches that are […]...
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Protecting vibration environments with zoning and land-use ordinances

Historically, the primary purposes of municipal land use zoning ordinances are to protect and promote a desired quality of life and to ensure that incompatible land uses do not occur. Typical environmental quality considerations include water, air, solid waste, and noise. Seldom, if ever, are vibrations considered; when they are, it is often in the […]...
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Noise Control

D. Pekrul, “Noise Control,” Chapter 2.6 in Handbook of Facilities Planning: Volume 2—Laboratory Animal Facilities, Theodorus Ruys, editor, Van Nostrand Reinhold, 1990....
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A Review of Noise Issues in Semiconductor Clean Rooms

The production of microelectronic semiconductor products requires a facility that is environmentally controlled and virtually free from contaminants. Airborne contaminants are controlled through the use of laminar-flow clean rooms whose air-handling systems provide highly-filtered air at rates of up to 100 air changes per hour, depending upon the class.  The air-handling systems in general and […]...
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Structural Systems

D. Pekrul and T Ruys, “Structural Systems,” (includes vibration and vibration control), Chapter 5.2 in Handbook of Facilities Planning: Volume 1—Laboratory Facilities, Theodorus Ruys, editor, Van Nostrand Reinhold, 1990....
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Vibration Considerations in Zoning

The primary purposes of municipal land use zoning ordinances are to protect and promote a desired quality of life and to ensure that incompatible land uses do not occur. Zoning considers aspects of community planning such as aesthetics, housing needs, protection and development of natural resources, population density, compatibility of adjacent land uses, and environmental […]...
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Noise Prediction and Control in Microelectronics Clean Rooms

Modern clean rooms of the sort used by the microelectronics industry in the fabrication of integrated circuits are typically quite noisy with levels lying in the range PNC 55 to 75. The noise can degrade the performance of production and test equipment. It also interferes with speech and telephone use and adds generally to the […]...
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Specifying and Interpreting a Site Vibration Evaluation

Many pieces of semiconductor production and test equipment are highly sensitive to vibration. Equipment manufacturers often provide environmental vibration limits and recommend, even require, a site vibration evaluation prior to installation of a system. Suppose a company is planning to install one of these systems. What does the manufacturer's vibration specification really mean? What should […]...
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Vibration and Noise Control in State-of-the-Art Clean Rooms

Vibration and noise may be ranked along-side other sources of microcontamination insofar as their effect on the IC fabrication process is concerned. In this paper we will discuss the design goals that are currently used. We will review the techniques that are available to quantify and control vibration and noise. Gordon, C. G. and H. […]...
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Vibrating Buildings

Please click on the Document Title above to see detail. Amick, H., "Vibrating Buildings," Development Magazine, pp. 43-45 (May/June 1988)....
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The Design of Low-Vibration Buildings Two Case Histories

Two case histories are presented that illustrate two aspects of the design problems.  The first is entitled “The Role of Special Foundations in the Design of Low Vibration Buildings.”  The Second is entitled “The Role of Sprung Floors in the Design of Low Vibration Environments.” Colin G. Gordon, “The Design of Low-Vibration Buildings Two Case […]...
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The Design of Low-Vibration Buildings for Microelectronics and Other Occupancies

In this paper I present an overview of the factors and problems that must be considered in designing low-vibration buildings. Subjects covered include vibration criteria for different occupancies, sources of vibration and response predictions, and major design factors for vibration control. Colin G. Gordon, “The Design of Low-Vibration Buildings for Microelectronics and Other Occupancies,” First […]...
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A Study of Low-Frequency Ground Vibration in Widely Differing Geographic Areas

The low-frequency ambient vibration existing on the ground is an important parameter in the siting of buildings that will contain equipment and processes that are sensitive to vibration. Such equipment is commonly used in "wafer fabrication plants" in which integrated circuit "micro-chips" are manufactured. Over the past 10 years or so, BBN Laboratories has undertaken […]...
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Cost-Effective Design of Practically Vibration-Free High-Technology Facilities

Advanced electro-optical equipment, such as that used in the production of integrated circuits, requires clean environments with extremely limited vibrations.  Ground motions, personnel activities, and mechanical equipment tend to produce unacceptably severe vibrations in high-technology facilities, unless suitable precautions are taken. Ungar, E. E., and Gordon, C. G., “Cost-Effective Design of Practically Vibration-Free High-Technology Facilities,” […]...
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Vibration Criteria for Microelectronics Manufacturing Equipment

The trend toward integrated circuits consisting of smaller, more tightly packed, elements has led to the requirement for greater precision and stability in microelectronics manufacturing and inspection equipment.  There exists the need for a better quantitative understanding of the effects of environmental vibrations on this type of equipment, in order to enable microelectronics facility designers […]...
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Vibration Challenges in Microelectronics Manufacturing

The manufacture of smaller, more tightly packed, integrated circuits requires facilities designed to meet stringent vibration requirements.  Vibration control is complicated by the need for extensive process support equipment and some service personnel in the vicinity of the sensitive machines.  Facility criteria that have been developed on the basis of earlier facility experience have tended […]...
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Power Transformer Noise—Prediction and Control

Power transformers located in outdoor substations can be a significant source of environmental noise disturbance, especially during nighttime hours.  The dominant characteristic of transformer noise is the low frequency  “hum” generated within the magnetic core as a result of the magnetostrictive properties of the core steel.  The core-generated noise consists of the harmonics of the […]...
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Fan Noise and its Prediction

When designing ventilation systems, one is often unable to obtain very specific details either of the fan to be used or of its noise as measured by the fan manufacturer under controlled conditions.  A number of empirical prediction formulae have been developed in the past and are frequently used by system designers and consultants in […]...
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Noise Generation by Fluid Flow Through Pipes

Much of the mid- and high-frequency noise in process plants derives from the flow of fluids through valves, orifices, and other pipework-located discontinuities.  The myriad of sources involved generates, within the plant, a sound field that is diffuse and uniform.  In this paper the author develops a tentative parametric formulation by which the generalized fluid […]...
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The Problem of Duct-Generated Noise and its Prediction

In this paper we will present some of the more fundamental notions of the phenomena classified as “subsonic aerodynamic noise.”  In light of these, we wish to discuss the mechanisms of noise generation responsible for the self-noise of sound-trap[s, dampers, diffusers and other duct-located flow discontinuities.  Furthermore, we will suggest, on the basis of some […]...
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