functional thin films and nanostructures for sensors. synthesis, physics, and applications

Functional Thin Films and Nanostructures for Sensors Integrated Analytical Systems Series Editor: Dr Radislav A Potyrailo GE Global Research, Niskayuna, NY For other titles published in this series, go to www.springer.com/series/7427 Anis Zribi • Jeffrey Fortin Editors Functional Thin Films and Nanostructures for Sensors Synthesis, Physics, and Applications Editors Anis Zribi United Technologies Corporation Fire and Security Kidde Detection Technology Research Development and Engineering Colorado Springs, CO USA Jeffrey Fortin GE Global Research Center Micro and Nano Structures Technologies Niskayuna, NY USA ISBN: 978-0-387-36229-8 e-ISBN: 978-0-387-68609-7 DOI: 10.1007/978-0-387-68609-7 Library of Congress Control Number: 2008944096 © Springer Science+Business Media, LLC 2009 All rights reserved This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights Printed on acid-free paper springer.com To our families and parents Olena, Nadia Michelle, Abi, Libby Foreword In recent years, there has been a convergence of fundamental materials science and materials processing methods This convergence, although highly interdisciplinary in nature, has been brought about by technologies such as bandgap engineering and related techniques that have led to application-specific devices such as lab-on-achip and system-on-a-chip The demand for reduced device size, device portability, and low power dissipation coupled with high speed of operation continues to dictate terms and conditions for the evolution of nanotechnology The present trend in approaches to systems manufacturing continues to focus on integration of multifunctionalities on the same chip These functionalities include, for example, onboard laser sources, sensors, and amplifiers Both the military and civilian markets continue to drive the research and development component In recent years, the emergency preparedness guidance systems have added excitement and curiosity to this expanding industry The outgrowth of technologies of interest for emergency preparedness includes the development of terahertz sources and detectors and systems for detection of explosives and concealed weapons, among others Sensors made from bulk materials have been around for a long time Enormous advances in the processing technologies of thin films have led to the ability to manufacture application-specific functional thin films These include transparent electrodes and antireflection films such as indium tin oxide, which serve as interface components between humans and electronic devices, or optical circuit elements used in optical communication networks, or as contacts and antireflection coatings in solar cells Products are also being developed with magneto-optical, electrochromic, or UV material for their use as functional thin films in optics Photonic crystals contain a variety of functional thin films; they require processing of thin films under very stringent control of their structure and properties For microelectromechanical systems (MEMS), in addition to silicon-based technology, ferroelectric thin films are being used in the fabrication of microactuators and micromotors, capacitors, and other thin-film devices Functional thin films are being used in the manufacture of devices such as surface acoustic wave (SAW) devices for high-frequency telecommunications filtering, infrared detectors, pressure sensors, accelerometers, force sensors, vibration, thickness, and chemical sensors and biosensors The reduction in size from bulk to micro- and nanostructured transducers, while promising high sensitivity, high speed, and increased selectivity, vii viii Foreword requires new design considerations that should consider factors such as integration with other devices and device lifetime Functional thin films offer an enormous infrastructure for a highly interdisciplinary integration of inorganic/semiconducting, organic/bio, and electronic/optoelectronic sensor systems The field is constantly evolving and will continue to so by absorbing novel materials approaches such as carbon nanotubes, high Tc superconductors, ferroelectrics, and thermoelectrics The chapters in this book are designed to give the reader the big picture, from the design phase to the implementation and realization of a transducer Every effort has been made to include the state-of-the-art in each chapter The intended audience is scientists, researchers, and engineers, however, graduate students will find the book to be very useful in their research and understanding of sensors and beyond The editors and contributors are leading researchers in industry and academia in their subject areas Newark, New Jersey February 2008 N M Ravindra Series Preface In my career I’ve found that “thinking outside the box” works better if I know what’s “inside the box.” Dave Grusin, composer and jazz musician Different people think in different time frames: scientists think in decades, engineers think in years, and investors think in quarters Stan Williams, Director of Quantum Science Research,Hewlett Packard Laboratories Everything can be made smaller, never mind physics; Everything can be made more efficient, never mind thermodynamics; Everything will be more expensive, never mind common sense Tomas Hirschfeld, pioneer of industrial spectroscopy Integrated Analytical Systems Series Editor: Dr Radislav A Potyrailo, GE Global Research, Niskayuna, NY The book series Integrated Analytical Systems offers the most recent advances in all key aspects of development and applications of modern instrumentation for chemical and biological analysis The key development aspects include: (i) innovations in sample introduction through micro- and nanofluidic designs; (ii) new types and methods of fabrication of physical transducers and ion detectors; (iii) materials for sensors that became available due to the breakthroughs in biology, combinatorial materials science, and nanotechnology; and (iv) innovative data processing and mining methodologies that provide dramatically reduced rates of false alarms A multidisciplinary effort is required to design and build instruments with previously unavailable capabilities for demanding new applications Instruments with more sensitivity are required today to analyze ultratrace levels of environmental pollutants, pathogens in water, and low vapor pressure energetic materials in air ix x Series Preface Sensor systems with faster response times are desired to monitor transient in vivo events and bedside patients More selective instruments are sought to analyze specific proteins in vitro and analyze ambient urban or battlefield air For these and many other applications, new analytical instrumentation is urgently needed This book series is intended to be a primary source of both fundamental and practical information of where analytical instrumentation technologies are now and where they are headed in the future Looking back over peer-reviewed technical articles from several decades ago, one notices that the overwhelming majority of publications on chemical analysis has been related to chemical and biological sensors and has originated from departments of chemistry in universities and divisions of life sciences of governmental laboratories Since then, the number of disciplines has dramatically increased because of the ever-expanding needs for miniaturization (e.g., for in vivo cell analysis, embedding into soldier uniforms), lower power consumption (e.g., harvested power), and the ability to operate in complex environments (e.g., whole blood, industrial water, or battlefield air) for more selective, sensitive, and rapid determination of chemical and biological species Compact analytical systems that have a sensor as one of the system components are becoming more important than individual sensors Thus, in addition to traditional sensor approaches, a variety of new themes has been introduced to achieve an attractive goal of analyzing chemical and biological species on the micro- and nanoscale M Willander et al Responsivity, a.u 198 μ = 30x104cm2 /Vs = 12x104cm2 /Vs = 6x104cm2 /Vs 1000 100 10 0.5 1.5 Frequency, THz 2.5 Fig 8.13 Normalized responsivity as function of THz radiation frequency calculated for detectors based on lateral Schottky junction with different electron mobility in the 2DEG channel The same ratio but for a resonant detector with an ungated channel (see Fig 8.12a) is given Rw ≈ 2 R0 ⎡sinh (pnw / 4Wu ) + cos2 (pw / 2Wu2 )⎤ ⎣ ⎦ (8.45) where (compare with Equation (8.43)) Wu = p e2 ∑ kmL (8.46) is the fundamental plasma frequency in the ungated 2DEG channel, as shown in Fig 8.13 Due to the large amplitude of the plasma oscillations forced by the incoming THz signal, the nonlinearities in question lead not only to the occurrence of the rectified component of the terminal current (or the pertinent voltage) but to the occurrence of higher harmonics Hence, the devices under discussion in this section can be used for plasma-assisted resonant detection as well as frequency multiplication Comments The concepts discussed above can result in the development of novel THz heterostructure devices such as detectors and frequency multipliers of THz radiation However, the device proposals considered not exhaust all interesting new ideas; Sensing Infrared and Terahertz Regions by Functional Films 199 see, for example, Govorov et al (1998, 1999), Ryzhii et al (2002 a-b), and Hanabe et al (2005) The specific features of plasma waves in the 2DEG channel can be used not only in the devices like those discussed above The linearity of plasma wave dispersion ( Re w α q ), relatively large plasma wave phase and group velocity (S » 108cm/s), and the possibility to control the plasma wave propagation and the interaction plasma waves between each other by locally applied voltage open up wide prospects to create new systems for processing of THz signals (in particular, delay lines, interferometers, etc.) Ultrasensitive THz Detector Using Cold-Electron Bolometer Cosmology experiments in the last few years (BOOMERanG, WMAP) have discovered that the universe consists of 73% dark energy, 23% dark matter, and only 4% ordinary matter The most shocking news is the acceleration of the universe by unknown forces (Breakthrough of the Year: Illuminating the Dark Universe 2003) Experiments to resolve the nature of these mysterious dark components will require a new generation of ultrasensitive detectors to get a more detailed picture of the cosmic microwave background radiation (Breakthrough of the Year: Illuminating the Dark Universe 2003) A new principle to realize an ultrasensitive THz detector was proposed by Kuzmin et al (Kuzmin 2000; Kuzmin et al 1998; Kuzmin and Golubev 2002) A novel concept of the cold-electron bolometer (CEB) is based on strong direct electron cooling of the absorber removing all incoming power from the supersensitive absorber to the readout system with considerably higher dynamic range This concept is purposed to overcome the main contradiction of supersensitive detectors: overheating by background power load due to high sensitivity of the detector Moreover, additional artificial dc heating of the TES (transition-edge sensor) for electrothermal feedback will be replaced by effective electron cooling (see Fig 8.14) This could entail a time Cold-Electron Bolometer (CEB) P0 -removed by SIN junctions Transition-Edge Sensor (TES) Ptotal = P0 + Pbias, Pbias = Pmax signal time electron cooling! (a) Te cool 100 mk Tph Pbias- heating! (b) P0 230 mk Te P0 100 mk Tph Fig 8.14 Comparison of the CEB and TES concepts (Kuzmin 2004) 230 mk Te heat Te 200 M Willander et al significant breakthrough in the development of supersensitive THz detectors due to the following In both concepts the background power load leads to overheating of the small absorber to the same temperature for a comparable volume of absorbers (V = 0.05 mm3) However, in turning point “2”, the CEB can cool down the electron temperature T back to phonon temperatures or lower due to direct electron cooling In contrast, the TES needs an additional dc heating to Tc for electrothermal feedback The advantage of cooling in comparison with heating is evident for supersensitive detectors • Achieving high sensitivity with direct electron cooling of an absorber with electron temperatures lower than bath temperature with the corresponding improvement of noise properties • CEB creates a new opportunity to avoid saturation by removing background power from the absorber (strong electrothermal feedback) by means of direct electron cooling The CEB can be easily fabricated on planar substrates in the form of multipixel arrays with possible multiplication using a SQUID or HEMT readout The CEB concept is in the process of development for a new generation of balloon-borne telescopes OLIMPO, CLOVER, and PILOT The goal of the first stage will be to achieve a noise equivalent power (NEP) of the order of 10–18 W/Hz1/2 with a SQUID readout system at 300 mK in voltage-biased mode The most developed superconducting bolometer (built in the 1970s) is the transition-edge sensor Some progress has been achieved after the introduction of electrothermal feedback (Lee et al 1996) Currently, the TES is the most widespread bolometer with a SQUID readout system available for multiplexing However, the TES has severe problems with saturation and the most drastic problem is artificial overheating by dc power for the feedback (after point “2” in Fig 8.14b) Additional heating requirements make all efforts in the area of deep cooling very challenging and not look promising in terms of attaining the limit performance of the bolometer In contrast to this overheating, the new concept of a cold-electron bolometer with direct electron cooling (Fig 8.15) was introduced by Kuzmin et al (Kuzmin 2000; Kuzmin et al 1998; Kuzmin and Golubev 2002) The CEB is the only active concept suggesting the removal of incoming background power from the supersensitive region of the absorber (point “2” in Fig 8.14a) This concept is likely to prevail in the long run over concepts requiring heating of the TES because it returns the system to the lowest temperature (noise) state In this state, the system shows the most responsivity to incoming THz signals and improved noise properties All the power of the signal is detected in measurements This bolometer can be especially effective for operation in the presence of a realistic background power load Theoretical estimations and preliminary experiments show that it is possible to realize the necessary sensitivity of better than 10−18 W/Hz1/2 with an antennacoupled CEB at a temperature of £0.3 K (Kuzmin and Golubev 2002) Additional advantages of such detectors include the possibility to operate in a wide range of Sensing Infrared and Terahertz Regions by Functional Films 201 Fig 8.15 Capacitively coupled CEB with SIN tunnel junctions for temperature measurements and electron cooling (strong electrothermal feedback) [Kuzmin 2004] An AFM picture of the right part of the bolometer shows SIN junction and a part of the large antenna Fig 8.16 Record electron cooling achieved at Chalmers University in real bolometer configuration due to improved quasiparticle trapping: (a) Au trap just near the junctions; (b) improved shape of superconducting electrode; (c) usual cross geometry [Kuzmin et al 2004, Agulo et al 2004] background load, easy integration in arrays, and the possibility of polarization measurements The effect of nonequilibrium electron cooling of CEB has been demonstrated by Nahum et al (Kuzmin 2004) for normal metal strip connected to SIN tunnel junctions The results of the Jyväskylä group on electron cooling from 300 to 110 mK are attracting strong interest from ESA The proposed NASA/ESA missions SPIRIT, SPECS, SAFIR, and “Far IR ProtoGalaxy Imager” will determine the highest level of requirements for bolometers in the nearest future No existing technology could satisfy these requirements Technological breakthrough is needed, first of all, to approach these requirements The proposed CEB concept could be a good candidate to become a leading concept in this development The latest achievement of the Chalmers group is a record electron cooling from 290 to 93 mK (Fig 8.16) due to improved trapping of hot quasi-particles in a super- 202 M Willander et al conductor (Masi et al 2004; Kuzmin and Mauskopf 2005) The achieved cooling results give a good basis for realization of high-performance CEBs working at real conditions of background power load Optimization of the CEB in Presence of the Background Power Load Model: Here we assume that the SIN tunnel junctions are voltage-biased, and the current is measured by SQUID The sensitivity of the device is then characterized by the current responsivity SI, which is the ratio of the current change detected by the SQUID and the change in the power load of the bolometer caused by a detected signal: ∂I ∂I∂T SI = w = (8.47) ∂P ∂Pw −i w cv L + 5SLTe + ∂T Here cn = gTe is the specific heat capacity of the normal metal; S L Te4 is the thermal conductance between electron to the phonon subsystems in the normal metal, ∑ is a material constant, ∧ is a volume of the absorber, Te and Tph are the electron and phonon temperatures of the absorber; ∂P / ∂T is the thermal conductance of the NIS junction, and P(t) is the incoming radio frequency power The noise is captured by the noise equivalent power, which is the sum of three different contributions, and is defined as 2 NEPtotal = NEPe2− ph + NEPSIN + dI SI2 (8.48) Here, NEPe2− ph = 10 kB SL (Te6 + Tph ) (8.49) is the nonequilibrium noise associated with electron–phonon interaction; NEP2SIN is the noise of the SIN tunnel junctions, and the last term dI is the noise of an SI amplifier (SQUID), dI , which is expressed in pA/Hz1/2 (Kuzmin et al 2004; Agulo et al 2004) The noise of the NIS tunnel junctions, NEP2SIN, has three components: shot noise 2eI/S2I, the fluctuations of the heat flow through the tunnel junctions, and the correlation term between these two processes: NEPSIN = dPw2 − 2 dPw dIw dIw + SI SI (8.50) Sensing Infrared and Terahertz Regions by Functional Films 8x10 203 −18 NEP NEP (W/Hz1/2 ) Goal: NEP=10−18 W Po= 0, R=6 k Ω 10−13 W, k Ω 10−13 W, 0,5 k Ω 0.75 Po- microwave background load 1/2 δ ISQUID= 50 fA/Hz 0.80 0.85 0.90 V/Δ 0.95 1.00 1.05 Fig 8.17 NEP in presence of various background power loads and various efficiencies of direct electronic cooling for bath temperature 100 mK (Kuzmin and Golubev 2002) It is necessary to take into account the effect of the electron cooling of the metallic strip by the NIS tunnel junctions Effect of background power load: Our analysis of the effect of background power load on noise performance for different configurations of CEB bolometers shows that the optimal configuration of the bolometer is a CEB with voltage-biased SIN tunnel junctions and a SQUID readout (Kuzmin et al 2004) The volume of the absorber is equal to 0.05 mm3, which is typical for our experiments The current noise of SQUID is equal to 50 fA/Hz1/2 in our simulations The results are shown in Fig 8.17 for two levels of microwave background power: P0= and 0.1 pW The latter figure is a realistic background power load P0 for a bandwidth of 10% at frequencies in the range of 300–1000 GHz for background temperature Tbg= K The first curve without background load (P0= 0) produces NEP = × 10−19 W for typical junction resistance (R) equal to kW A considerable increase of the NEP to × 10−18 W/Hz1/2 is obtained for P0= 0.1 pW The electron temperature also increases from 100 to 230 mK Decreasing R to 0.5 kW improves the efficiency of the electronic cooling and returns the NEP to the acceptable level of × 10−19 W/Hz1/2 and Te to the level of 100 mK The NEP goal for the future projects is 10−18 W/Hz1/2 (Kuzmin 2000; Kuzmin et al 1998; Kuzmin and Golubev 2002) and can be achieved with these system parameters Concept of an optimal bolometer: We have analyzed the optimal CEB in the presence of the final background power load (P0 = 0.1 pW) for fixed parameters of the SQUID-amplifier (10 fA/Hz1/2) at T = 300 mK (Agulo et al 2004) The optimal 204 M Willander et al regime can be realized when thermal “cooling conductance” through the tunnel junctions dominates the “fundamental” electron–phonon conductance In these circumstances, an NEP level of 10−18 W/Hz1/2 at 300 mK can be achieved The dependences of the NEP on a volume of the absorber show that there is no optimal value of NEP for the volume of absorber L The reason for the flattening for small volumes is that we have achieved full transference of P0 to the amplifier, so that the NEPe-ph constitutes less than 50% of the total NEP The critical point of the optimal regime is a point of equality of NEPSIN and NEPe-ph at L = 0.003 mm3 The dependences of the NEP on the resistance of the SIN tunnel junctions R gives the optimum value R around 1.5 kW For higher values of R, the electron cooling is not as effective and responsivity is decreased, increasing noise of the SIN junction (4) and SQUID (2) Decrease of R lower than the optimal point increases the shot noise (reverse proportional to R) without any increase in responsivity because of saturation in transferring power Expected results: Improvement of noise equivalent power of the bolometer receiver due to realization of the optimal concept to the level of NEP ~ 10−18 W/Hz1/2 at 300 mK is expected Ultimate Noise Performance of CEB-General NEP Formula This question has arisen in relation to the highest requirements on NEP for future NASA missions The question is how realistic are these requirements on NEP = 10−20 W/Hz1/2 The ultimate performance of CEB and other concepts has been analyzed (Kuzmin 2004) The NEP is determined by shot noise due to power load Other sources of noise are neglected due to small values For the level of P0 = 10 fW this limit can be achieved using relatively low temperatures (~100 mK) and small volume of the absorber (∧ ≤ 0.002mm3) when we can neglect the electron–phonon noise component A general ultimate NEP formula has been derived (Kuzmin 2004): NEPshot = (2 P0 Equant )1/ (8.51) where P0 – background power load Equant – energy level of P0quantization Equant = kBTe – for normal metal absorber Equant = Δ – for superconducting absorber The ultimate NEP can be estimated for different bolometers for rather low P0 = 10 fW: CEB: Te = 50 mK, NEPshot = 1*10−19 W/Hz1/2 TES: Te= 500 mK, NEPshot = 4*10−19 W/Hz1/2 KID: T = K (Δ= 200 meV), NEPshot = 7*10−19 W/Hz1/2 Sensing Infrared and Terahertz Regions by Functional Films 205 The lowest NEP can be achieved for CEB with the lowest level of quantization However, even these extreme parameters of P0 and Equant show that it is rather unrealistic to achieve NEP = 10−20 W/Hz1/2 as announced in NASA requirements for future missions This formula (8.51) is used for estimation of ultimate parameters of CEB and other bolometers for given parameters of detector systems The work on analysis of ultimate parameters of CEB will be prolonged Preliminary results: Record attowatt sensitivity of the cold-electron bolometer The Chalmers group has made the measurements of the cold-electron bolometer in a current-biased mode They have measured the voltage response to applied low-frequency modulation of the heating current on the normal metal absorber The detector responsivity was 1.5 × 1010 V/W at 35 Hz at 100 mK The frequency dependence of responsivity was tested and was found to decrease with increasing frequency of the modulated signal owing to the inclusion of the signal attenuation due to cryogenic filters The corresponding noise equivalent power of the bolometer was obtained, using an operational amplifier at 300 K from the noise of the bolometer divided by the detector responsivity (Fig 8.18) The record noise equivalent power for the CEB was found to be better than 10−18 W/Hz1/2 at 100 mK and at frequencies higher than 100 Hz for a background power load of 2.6 fW The next step is measurement of NEP in voltage-biased mode For the next breakthrough in our knowledge about dark matter and dark energy, we need a new generation of detectors Priority of this topic can be determined as 96% (dark universe) to 4% (ordinary matter) A cold-electron bolometer is a good candidate to become the leading concept in this development NEP Total NEP Bolo NEP Amp NEP (10−18 w/Hz1/2) 100 frequency (Hz) 1000 Fig 8.18 The dependence of the total, bolometer, and amplifier NEP of the cold-electron bolometer to the modulation frequency We have stepped to the 19th power of CEB sensitivity for frequencies higher than 100 Hz The dashed line represents the value of the NEPs as predicted by the nonequilibrium theory of the CEB 206 M Willander et al Realization of the cold-electron bolometer would be the turning point from artificial heating (TES) to effective electron cooling lower than phonon temperature which should bring clear benefits for supersensitive detectors The famous contradiction between supersensitivity and saturation can be overcome by strong electrothermal feedback removing power to the next stage with higher dynamic range The CEB concept could be implemented for new balloon telescopes OLIMPO, CLOVER, and PILOT Summary We have discussed sensing of two parts of the EM spectra, namely the IR region and the THz region For the IR region we have particularly analyzed QWIP, QRIP, and QDIP and found 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60, 61, 62, 63, 70, 76, 102, 110, 127, 128, 132 Glancing-angle 32, 36, 48, 63, 64, 77, 78 Oblique angle 46, 47, 48, 50, 63 Material Process 21, 31 Pulsed-laser 36 Vapor 31, 32, 33, 35, 36, 37, 45, 77, 78, 149, 152, 187 Electrochemical 32, 41, 63, 69, 77, 78 Thin film 32, 38, 46, 70, 76, 93, 100, 102, 112, 115 Nanostructure 77, 78 Sol-gel 151, 152 Detector Photo 94, 133, 170, 171, 172, 173, 174, 181, 183, 186, 208, 209, 210 Dielectric 10, 15, 16 Diffusion 7, 8, 21, 100, 127, 140, 153 Drift 5, 8, 28, 94, 101, 130, 132, 138 E Electronics 3, 5, 7, 9, 29, 80, 81, 82, 84, 96, 97, 100, 109, 134, 147, 161, 178 Energy 3, 6, 10, 11, 12, 13, 14, 15, 17, 18, 21, 27, 28, 36, 39, 68, 70, 71, 82, 88, 89, 90, 96, 101, 102, 106, 107, 111, 112, 113, 114, 123, 124, 129, 137, 170, 171, 173, 174, 176, 178, 185, 188, 189, 190, 191, 192, 193, 201, 206, 207 Surface 11, 13 211 212 Etching 2, 31, 32, 41, 42, 45, 70, 71, 72, 76, 78, 80, 83, 84, 165 Error Systematic Random F Fabrication 1, 2, 9, 15, 20, 24, 31, 32, 33, 34, 36, 38, 39, 44, 51, 55, 58, 59, 62, 63, 64, 65, 66, 69, 70, 71, 73, 74, 75, 77, 79, 80, 81, 82, 83, 84, 85, 87, 108, 114, 135, 137, 142, 144, 147, 151, 161, 162, 164, 165, 167, 171 Force Dispersion 11, 123 London 11 Van Der Waals 11 Frequency Resonance 2, G Grains 12 H Hysteresis 5, 8, 127, 128 Homogeneity 13, 14 I Index Refractive 11, 16, 67, 99, 133, 134, 137, 150 Inhomogeneity 13, 14 Interactions Ionic 11 Interface 12, 61, 95, 133, 134, 137, 140, 172, 187 L Liquid 11, 12, 13, 14, 28, 32, 34, 38, 39, 41, 44, 67, 75, 89, 95, 105, 109, 110, 116, 120, 122, 123, 139, 167 M Materials Bulk 11, 15 Selection 1, 9, 16, 147 Measurand 3, 4, 5, 6, 7, 8, 9, 10, 17, 18, 19, 21, 22, 23, 24, 25, 26, 27, 28, 74, 198 Index MEMS 2, 16, 19, 21, 22, 24, 29, 68, 69, 74, 75, 76, 79, 81, 82, 84, 87, 88, 106, 129, 148, 149, 151, 152, 153, 161, 167 Metal 11, 12, 14, 15, 16, 21, 22, 36, 39, 44 Miniaturization 2, 106, 137, 138, 140, 142, 161, 167 Modulus Elastic/Young’s 11, 13, 16, 140, 151, 156, 159 Model 9, 12, 13, 14, 15, 16, 19, 39, 63, 132, 137, 138, 142, 144, 145, 176, 181, 190, 191, 192, 193, 195, 204 Multilayers 2, 98 N NanoStructure 1, 2, 3, 7, 12, 13, 15, 16, 17, 27, 31, 32, 37, 38, 41, 44, 49, 50, 51, 52, 53, 55, 59, 60, 62, 63, 64, 72, 73, 74, 76, 77, 78, 79, 81, 83, 87, 129, 134, 137, 169, 170, 187 Technology 16, 43, 63, 64, 81, 82, 83, 85, 208 Scale 11, 12, 13, 14, 15, 60, 61, 62, 63, 80, 81, 82, 85, 137, 140, 144 Materials 11, 12, 13, 14, 63, 81, 114, 129, 134 Morphology Fluid 13, 14, 16 Instrument 10 Particle 11, 15, 16, 27, 31, 32, 41, 44, 45, 62, 76, 77, 78, 80, 81, 107, 134, 135, 139, 140, 144 Regime 11, 13 Noise 3, 6, 7, 8, 10, 18, 24, 94, 95, 96, 110, 111, 119, 129, 135, 137, 138, 150, 161, 187, 202, 204, 205, 206, 207 P Point Melting 11, 12, 16 Polymer 14, 16, 21, 22, 23, 28, 31, 39, 40, 41, 42, 43, 62, 63, 66, 70, 72, 73, 76, 77, 78, 79, 80, 82, 83, 107, 108, 111, 112, 114, 116, 119, 123, 124, 125, 126, 127, 129, 130, 131, 132, 134, 135, 138, 139, 140, 141, 142, 143, 144, 145, 150, 153, 154 Precision 2, 5, 8, 24, 29, 100, 102, 137, 161 Index Process Fabrication 2, 9, 20, 32, 51, 62, 66, 74, 147, 161, 162, 164, 165 Properties Physical 132, 145 Chemical 2, 11 Mechanical 11, 127 Optical 14, 15, 16, 62, 63, 64, 134, 135, 139 Q Quantitative Sensor 4, 5, 132 R Range Dynamic 5, 21, 22, 108, 109, 149, 150, 201, 208 Reliability 5, 10, 15, 108 Repeatability Resolution 5, 7, 8, 24, 66, 67, 68, 70, 80, 81, 84, 108, 134, 135, 137 Rheology 10 S Scaling 2, 8, 9, 10, 11, 13, 15, 16, 28, 31, 32, 47, 50, 58, 69, 83, 110, 112, 132, 143, 144, 162 Selectivity 2, 5, 8, 9, 71, 106, 108, 109, 110, 116, 117, 123, 129, 138, 165 Self-assembly 2, 32, 64, 76, 77, 78, 80, 106 Semiconductor 27, 29, 41, 62, 63, 64, 65, 70, 71, 72, 74, 75, 79, 82, 93, 101, 114, 129, 142, 147, 150, 152, 169, 170, 187, 188, 193, 208, 209, 211 Sensitivity 5, 6, 7, 8, 9, 13, 15, 18, 21, 22, 23, 28, 60, 88, 91, 92, 93, 94, 95, 108, 109, 112, 116, 119, 125, 126, 127, 129, 130, 135, 137, 143, 150, 167, 171, 182, 201, 202, 204, 207, 208 Signal-to-noise ratio 95, 97, 137, 138, 187 Silicon 2, 19, 20, 21, 22, 23, 25, 26, 28, 70, 71, 72, 75, 76, 77, 80, 83, 99, 150, 152, 153, 162, 163, 164, 165, 167, 187 Solid 12, 13, 29, 34, 36, 39, 41, 62, 63, 72, 81, 82, 83, 98, 99, 107, 116, 134, 140, 141, 142, 144, 167, 169, 192 213 Spectrum 3, 15, 18, 26, 89, 90, 91, 96, 101, 102, 103, 173, 174, 175, 196, 197 Stress 8, 18, 19, 20, 21, 24, 27, 29, 65, 74, 147, 148, 150, 152, 154, 157, 158, 159, 160, 163, 164, 166, 167, 190, 193 Surface 2, 3, 11, 12, 13, 14, 19, 21, 24, 27, 29, 35, 38, 41, 45, 46, 48, 49, 50, 55, 59, 60, 61, 68, 69, 70, 71, 72, 74, 75, 81, 83, 89, 96, 98, 102, 107, 112, 113, 125, 130, 132, 134, 135, 138, 140, 142, 144, 149, 159, 164, 167 System 2, 3, 7, 9, 11, 24, 28, 33, 39, 45, 46, 53, 62, 63, 67, 68, 69, 71, 80, 81, 82, 83, 88, 89, 93, 94, 95, 96, 97, 100, 101, 103, 105, 106, 107, 109, 110, 120, 126, 127, 132, 134, 135, 137, 138, 139, 140, 142, 143, 144, 145, 149, 151, 161, 162, 167, 174, 188, 190, 193, 195, 196, 197, 201, 202, 204, 205, 207, 208 T Temperature glass-transition 11, 12, 72, 116 Tension Surface 12, 41 Thin films Functional 2, 3, 13, 76, 78, 87, 148, 150, 161, 166 Time Response 5, 7, 25, 93, 94, 95, 101, 103, 127 Threshold Sensor Transducer 1, 2, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 17, 18, 22, 65, 66, 67, 70, 73, 74, 75, 76, 77, 79, 80, 105, 106, 107, 108, 110, 111, 112, 114, 123, 127, 129, 137, 138, 141, 142, 144, 145, 166 Transduction 3, 6, 9, 10, 15, 17, 18, 19, 21, 22, 24, 25, 27, 28, 105, 106, 107, 109, 110, 113, 114, 116, 123, 129, 132, 138, 147, 148 V Variability 2, 8, 97 Van der Waals 11 Viscosity 11, 13, 14, 16, 18, 39, 41, 44, 195 ... Zribi • Jeffrey Fortin Editors Functional Thin Films and Nanostructures for Sensors Synthesis, Physics, and Applications Editors Anis Zribi United Technologies Corporation Fire and Security Kidde... design considerations related to the use of functional thin films and nanostructures, and specific case studies of functional thin films and nanostructure applications in sensing Part of our motivation... functional thin films and functional nanostructures Thin films and nanostructures play an increasingly important role in state-of-the-art sensors and actuator technologies both as transducers (functional