bluuebunny/crossref_metadata_2025 huggingface dataset:
Failure Mechanism by Organic Contaminants in Si Device Fabrication
Authors: Kim Kwang-Salk , Kim Ja-Young , Lee Ki-Sang , Kang Hee-Bok , Lee Bo-Young
Published: October 2008

Adverse influences of organic contaminants on electronic devices have been studied and the results are reported. Contamination of silicon wafers by organic compounds during their manufacturing processes has been clearly demonstrated by a few surface analytical techniques. Silicon wafers were intentionally contaminated by one of the major contaminants, bis(2-ethylhexyl) phthalate; its incorporation into the silicon oxide layer during thermal oxidation of silicon and its influences on device performances have been evaluated in detail by monitoring the breakdown voltages. During thermal oxidation of the contaminated silicon surface, the atomized carbon species produced from pyrolysis of organic contaminants help grow the oxide thicker, expand the silicon oxide lattice, and degrade the silicon oxide, which was shown by transmission electron microscopy and secondary ion mass spectroscopy, and finally exert adverse influences on the device performance.
Study of Organic Contaminants Analysis using TD-GCMS on Silicon Wafer Surfaces
Authors: Taira Toshikazu , Shiramizu Yoshimi , Watanabe Masaharu , Kawai Nobuyuki
Published: October 2008

We are reviewing about the method of analyzing wafer surface organic contamination. Although TD/GC-MS is to be used by the SEMI method used now, it is because it is whether all organic compounds are analyzed appropriately and a question. This time, we clarified the problem in experimenting.
Measurements of Dislocation Locking by Near-Surface Ion-Implanted Nitrogen in Czochralski Silicon
Authors: Alpass Charles , Murphy John , Jain Amitabh , Wilshaw Peter R.
Published: October 2008

A modified dislocation unlocking technique is used to measure dislocation locking due to nitrogen implanted into Czochralski silicon. The results show that near-surface dislocations can be locked by implanted nitrogen. The magnitude of the locking measured suggests that nitrogen transport proceeds by a dissociative mechanism, where transport occurs by the splitting of immobile dimers into fast monomers, rather than movement of nitrogen dimers. In other experiments, nitrogen-doped float-zone silicon is investigated using the standard dislocation unlocking technique. The results give an activation energy for effective nitrogen diffusion in silicon of 3.24{plus minus}0.25eV at 500 to 750{degree sign}C. Using the assumption that the dislocation locking strength per nitrogen atom is the same as that of oxygen, a value of 200,000cm2s-1 can be inferred for the effective diffusivity pre-factor. If analysed using the dissociative model, an activation energy of 1.1 to 1.4eV is found for nitrogen monomer diffusion, with a diffusivity pre-factor of 30cm2s-1.
Theoretical Analysis of Thermally Induced Structural Deformation and Relaxation of Silicon Wafer
Authors: Kumar B. H. , Roy Shantanu , Pitney John A. , Torack Tom , Kommu Srikanth
Published: October 2008

This work is focussed on the modeling and simulation of structural deformation of silicon wafers during their initial heat-up in a CVD reactor chamber, prior to the chemical vapor deposition process. The wafer structural deformation can lead to some detrimental defects that are unacceptable for semiconductor device processing. In this work, we have developed a numerical model to simulate the wafer structural deformation as a function of some key process parameters. The main objective of this simulation work is to provide guidance on the optimal process conditions at which the wafer deformation and the resulting defects can be minimized.
Cathodoluminescence Assessment of Low Temperature Gettering in Silicon and a Novel Technique for Estimating Bulk Minority Carrier Lifetime in Silicon
Authors: Fraser Kieth , Falster Robert , Wilshaw Peter R.
Published: October 2008

The effect of low temperature anneals ({less than or equal to}500C) on Cz-Si minority carrier lifetime has been investigated using near-band-edge cathodoluminescence (CL) The low temperature anneals are intended to produce efficient gettering by taking advantage of the increasing supersaturation of impurities as temperatures are reduced. It is found that the anneals affect the CL efficiency through several different mechanisms and that annealing under "dirty" conditions does not introduce significant amounts of electrically active impurities into the material. In order to aid the interpretation of experimental results, modelling of the effect of different sample parameters on CL is carried out. Using this theoretical work, an experimental method is developed for measuring minority carrier lifetime using CL which is independent of surface recombination.
300mm Wafer Stain Formation by Spin Etching
Authors: Sato Keisuke , Mashimoto Satomi , Watanabe Masaharu
Published: October 2008

Stain film (porous silicon) formation by immersion is reported. The Stain film formation on 300mm wafers by surface treatment is accomplished using SPIN ETCH. It is found that stain film has resistivity.
The Way of Making Monoisotopic FZ-Si Crystals for the New kg Mass Unit Standard and for Basic Research
Authors: Riemann Helge P. , Abrosimov Nikolai , Hallmann-Seiffert Birgit , Kaliteevski Alexei , Godisov Oleg , Gusev Anatoly , Bulanov A. D. , Pohl Hans-Joachim , Becker Peter
Published: October 2008

The naturally based redefinition of the kg unit being aimed by the Avogadro project ultimately requires a precise 1kg-sphere of mono isotopic silicon with practically perfect crystallinity. Silicon isotopes (28, 29, 30) can be effectively separated by the ultra-centrifugation technique. A large amount (ca.10kg) of gaseous 28SiF4 was extraordinarily highly enriched up to 99.996% using ca. 240 specially interconnected centrifuges over 6 months. Then, 28SiF4 was transformed to 28SiH4 and purified by cryo distillation. Polycrystalline 28Si was pyrolytically deposited to a cylindrical 6kg rod. After multiple FZ-purification, a dislocation-free 28Si FZ crystal of 4,5 kg mass was grown, just enough for two 1kg spheres and auxiliary samples. The enrichment was still 99,994%. Similarly, small (10-20g) 29Si and 30Si crystals were prepared for basic research needs. Si28 enables dramatic line narrowing improving deep and shallow defect spectroscopy. Under magnetic field, electronic and nuclear spins embedded in a zero-spin 28Si matrix could be individually determined.
High-Performance Organic Thin-Film Transistors for Flexible AM-OLED Displays
Authors: Tokito Shizuo
Published: October 2008

The electrical performance of an organic thin-film transistor (OTFT) based on pentacene was improved significantly through the control of both layer surfaces and device interfaces. Moreover, a 5.8-inch flexible organic light-emitting diode (OLED) display consisting of the OTFT and OLED devices on a thin plastic substrate was demonstrated. While operating the OTFT backplane at relatively low voltages below 15 V, good average field-effect mobility levels of 0.1cm2/Vs were exhibited. The flexible AM-OLED panel displayed distinct color moving images at a frame rate of 60 Hz.
Fabrication of Flexible TFTs on a Heat-Resistant Transparent Polymer using the Standard a-Si TFT Process above 300ºC
Authors: Hattori Takashi , Kato Midori , Wakagi Masatoshi , Yoshida Takehiko , Hatano Mutsuko
Published: October 2008

A method for fabricating thin-film transistors (TFTs) on flexible substrates using a spin-coated heat-resistant transparent polyimide analog polymer, polybenzoxazole (PBO), was developed. Since this material is heat-resistant up to 350ºC, it can withstand the conventional above-300ºC a-Si TFT process. With XeCl excimer laser exposure, the PBO layer with a-Si TFTs could be easily separated from the glass substrate without any damage to the TFTs.
The Characteristics of Hot-Carrier Stressed Bottom-Gate Polycrystalline Silicon Thin-Film Transistors Employing Alternating Magnetic-Field-Enhanced Rapid Thermal Annealing
Authors: Lee Won-Kyu , Shin Hee-Sun , Cho Kyusik , Choi Joonhoo , Kim Chi-Woo , Han M. -K.
Published: October 2008

We have evaluated the reliability of the bottom-gate (BG) polycrystalline silicon (poly-Si) thin-film transistors (TFTs) by employing alternating magnetic-field-enhanced rapid thermal annealing (AMFERTA) under the hot-carrier stress condition. The on-current was reduced due to the trap state creation caused by hot-electrons near drain junction. The off-current was suppressed due to the negative charge trapping near drain junction region. The temperature annealing after hot-carrier stress removed an amount of trap states in the drain junction. However, the tapped negative charges still remained near the drain junction. This charged region acts like lightly doped drain. Therefore, the sufficient annealing condition might be restored to the reduced on-current level without increasing off-current.
Analysis of the Hysteresis Behavior in Poly-Si TFTs Using On-the-Fly Measurement
Authors: Kawamura Tetsufumi , Uchida Hisatoshi , Matsumura Mieko , Kageyama Hiroshi , Hatano Mutsuko
Published: October 2008

The hysteresis behavior in p-type poly-Si TFTs causes malfunctions in analog circuits. To analyze the hysteresis, we adopted the On-the-Fly measurement that was used in the analyses of the negative bias temperature instability of Si LSIs. We modified the measurement for poly-Si TFTs and monitored the hole trapping from the fully detrapped states in order to quantitatively evaluate the hysteresis. A TFT annealed at 550oC had smaller trapping than a TFT annealed at 490oC due to fewer Si-OH bonds.
Reliability Analysis of Single Grain Si TFT using 2D Simulation
Authors: Baiano Alessandro , Tan Jaming , Ishihara Ryoichi , Beenakker Kees
Published: October 2008

Single grain thin-film transistors (SG-TFTs) fabricated inside a location-controlled grain by µ-Czochralski process have as high as SOI performance despite low-temperature process. Reliability of SG-TFTs is a very important issue. The degradation effects of SG-TFTs under bias-stress conditions are mostly mobility degradation, threshold voltage changing, subthreshold characteristic degradation. These effects need to be modeled in order to predict the reliability for any bias-stress conditions applied to the device. To obtain that, extraction parameters strategy of degradation model has to be found out. The degradation model is thus confirmed for different bias-stress conditions.
A Vertical Thin Film Transistor Based on Low Temperature Technology (T<600oC)
Authors: Toure Himi D. , Gaillard Thierry , Coulon Nathalie , Bonnaud Olivier
Published: October 2008

A new concept of vertical Thin Film Transistor (TFT) family called Thin Film Transistor Comb (TFTC) using only low temperature process (less than 600{degree sign}C) based on polycrystalline silicon (polysilicon) has been fabricated. This structure, compatible with glass substrate, can have up to 5 teeth and allows increasing channel width simultaneously to a better control and reduction of channel length, leading to an increase of the average current and device densities. In contrast to other vertical TFTs, the channel of TFTCs is made of non-intentionally doped silicon between two layers in-situ doped polysilicon, all deposited by low pressure chemical vapor deposition. Analyses of characteristics of main studied pattern, a comb with 3 teeth, show a high on-current, a threshold voltage of 1.6V, a transconductance of 97µS, a very low gate leakage current, but in the first layout a high off-current due to the large area of the drain and source overlapping.
Formation of Si Nanocrystals in SiOx Films Induced by Thermal Plasma Jet Annealing and Its Application to Floating Gate Memory
Authors: Okada Tatsuya , Higashi Seiichiro , Kaku Hirotaka , Furukawa Hirokazu , Miyazaki S.
Published: October 2008

Polycrystalline Si (poly-Si) thin film transistors (TFTs) have been utilized for logic and analog circuits in display applications. For further improvement in functionality, non-volatile memory operation of TFT has been anticipated. In MOSFET applications, Si nanocrystals embedded in SiO2 matrix are used as charging nodes in floating gate memory devices. Si nanocrystals are advantageous in terms of better retention characteristics compared to poly-Si floating gate because charged dots are electrically separated each other and charge escape via SiO2 defects are suppressed to a small number. Recently, good performance of low-temperature processed TFT memory using Si nano crystals formed by plasma enhanced chemical vapor deposition (PECVD) has been reported.
Microcrystalline Si1-xGex Deposited by Magnetron Sputtering
Authors: Hiroe Akihiko , Goto Tetsuya , Teramoto Akinobu , Ohmi Tadahiro
Published: October 2008

Microcrystalline Si1-xGex (x~0.8) films have been deposited by RF magnetron sputtering with source frequency of 100MHz. Crystallinity of deposited films has been evaluated by spectroscopic ellipsometry. Detailed investigation on the deposition behavior has been carried out, and it was found out that threshold temperature for crystalline phase formation is about 300oC. At the substrate temperature of 300oC crystallinity depends on film thickness, i.e. as film becomes thicker, crystallinity increases from less than 5% to about 60%. On the other hand, at substrate temperature of 350oC, crystalline formation begins to take place almost from the beginning of deposition. Nucleation site density is lower for 300oC, which in turn results in the higher surface crystallinity compared with the films deposited at 350oC. Substrate bias effect on deposition behavior was also investigated. Substrate bias improves the crystallinity of the films deposited at 300oC while it actually damages crystalline phase formed at 350oC.
Etching Treatment of MILC Poly-Si TFTs Using CF4 Plasma to Improve Electrical Performance
Authors: Chang Chih-Pang , Wu YewChung Sermon , Chen Chien-Chih , Lai Ming-Hui
Published: October 2008

In this study, CF4-plasma was employed to improve the electrical performance of metal-induced lateral crystallization (MILC) polycrystalline silicon thin film transistors (poly-Si TFTs). It was found that CF4-plasma minimize effectively the trap-state density during etching surface of channel, leading to superior electrical characteristics such as high field-effect mobility, low threshold voltage, low subthreshold slope, low leakage current, and high on/off current ratio.
Improvement of Electrical Characteristics in SPC-Si TFT Employing H2 Plasma Treatment
Authors: Park Sang-Geun , Kim Sun-Jae , Lee Jeong-Soo , Kim Chang-Yeon , Han M. -K.
Published: October 2008

We fabricated PMOS SPC-Si TFTs which exhibit better uniformity than ELA poly-Si TFTs, and superior electrical stability compare to a-Si:H TFTs. We applied various H2 plasma treatments on solid phase crystallized silicon (SPC-Si) active layer prior to SiO2 gate insulator deposition, in order to improve the interface of SPC-Si. When the H2 plasma treatment with 100W power of PE-CVD was applied in the SPC-Si for 5 minutes, the electrical characteristics of the fabricated SPC-Si TFT was improved. It showed VTH of -3.91V, field effect mobility of 22.68cm2/Vs and subthreshold swing of 0.64 while the VTH of the other SPC-Si TFT was larger than -5V. We also showed that the stability of SPC-Si TFT was better than that of both poly-Si TFT and a-Si:H TFT.
All-solution-processed Organic Thin-film Transistors using Inkjet-printed Silver Electrodes
Authors: Kim Jinwoo , Jeong Jaewook , Park Sung J. , Kwon Soon-Ki , Kim Jang-Joo , Hong Yongtaek
Published: October 2008

We report all-solution-processed organic thin-film transistor using inkjet-printed silver electrodes, spin-coated cross-linked poly(4-vinylphenol) (PVP) as a gate dielectric material, and spin-coated 6,13-bis(triisopropylsilylethynyl) pentecene (TIPS-pentacene) as an active layer. Edge-scalloping effect was observed for printed silver source/drain electrodes and analyzed to obtain effective channel length of this device. We obtained a mobility up to 0.08 cm2/Vs, which is as high as that of spin-coated TIPS-pentacene OTFT deposited on conventionally deposited metal and/or insulating layers, without current crowding at source/drain contact. We also studied inkjet-printed TIPS-pentacene OTFT using silver source/drain electrodes printed on thermally grown silicon dioxide gate dielectric layer on heavily doped p-type silicon wafer. This device showed a mobility of 0.06 cm2/Vs, threshold voltage of -3.4V, subthreshold swing of 2.41V/dec, and on/off ratio of 105.
Flexible High Mobility Pentacene Transistor with High-k/low-k Double Polymer Dielectric Layer Operating at -5 V
Authors: Lee Kwang H. , Lee Kimoon , Lee GyuBaek , Oh Min Suk , Choi Jeong-M. , Im Seongil , Jang Sungjin , Kim Eugene
Published: October 2008

We report on the fabrication of pentacene-based thin-film transistors (TFTs) with double polymer dielectric composed of 30 / 45 nm-thin low-k poly-4-vinyphenol (PVP) and 110 nm-thick high-k poly(vinylidene fluoride/trifluoroethylene) [P(VDF-TrFE)] dielectric on polyethersulfone (PES) films. Our 140 and 155 nm-thick double (high-k/low-k) polymer showed a good dielectric strength of 1 and 1.5 MV/cm, a high capacitance of 31 ~ 34 and 27 nF/cm2 with k = ~ 5, respectively. Based on 140 and 155 nm-thick double polymer dielectric, our flexible pentacene TFT displayed a high saturation mobility of 1.39 and 1.23 cm2/V s, a threshold voltage of -2.3 and -2.0 V, respectively, and on/off ratio of 103, stably operating under -5 V.
Organic Field-effect Transistors Based on 2,9-Disustituted Pentacenes
Authors: Kunugi Yoshihito , Busujima Yuka , Ikari Mitsuaki , Okamoto Kazuo , Ogino Kenji
Published: October 2008

Organic field-effect transistors based on vapor deposited films of 2,9-diethylpentacene (C2-PEN), 2,9-dibutylpentacene (C4-PEN), 2,9-dioctylpentacene (C8-PEN) and 2,9-bis(perfluorobutyl)-pentacene (C4F9-PEN) were successfully fabricated. All the alkylpentacene based OFETs showed typical p-channel FET characteristics, and the best field-effect mobility of 0.05 cm2V-1s-1 with on/off current ratio of ~104 was obtained for the C2-PEN based OFET. Interestingly, the filed-effect mobility decreased as alkyl-chain length becomes longer. According to the molecular orbital (MO) calculations, the 2,9-dialkylpentacenes form doubly bent molecular structures in which the all-anti alkyl groups are not lie on the same plane as that of the pentacene core. The alkyl-chains may hinder the intermolecular interactions and overlap, meaning the poor intermolecular charge transfer. It was found that the substitution of p-type pentacene core with perfluoroalkyl groups affords n-type material. According to the MO calculation, LUMO energy level (-2.94 eV) of C4F9-PEN are fairly lower than that of pentacene.
Stability Improvement of Gallium Indium Zinc Oxide Thin Film Transistors by Post-Thermal Annealing
Authors: Jung Ji-Sim , Son Kyoung-Seok , Kim Tae-Sang , Ryu Myung-Kwan , Park Kyung-Bae , Yoo Byung-Wook , Kwon Jang-Yeon , Lee Sang-Yoon , Kim Jong-Min
Published: October 2008

The effects of post-thermal annealing on the stability of Ga2O3-In2O3-ZnO (GIZO) thin film transistors (TFT) were investigated by comparing the GIZO TFTs annealed for 3 hour and for 65 hours under high-field bias stress, light illumination, and long-term storage in air. We found that the poor stability of the GIZO TFTs under these stresses was remarkably improved after 65 hours' post-thermal annealing at 250 OC. The improvement of the stability is ascribed to the reduction of the trap sites in the GIZO layer and curing of weak atomic bonds otherwise susceptible to breaking during the stress.
Low Temperature Post-Annealing of ZnO Thin-Film Transistors with High-k Gate Dielectrics
Authors: Chen Henry J. H. , Yeh Barry B. , Chou Wei-Yang
Published: October 2008

This work addresses the thin film analysis of ZnO and electrical characteristics of ZnO TFTs with HfO2 high-k gate dielectrics after low temperature post-annealing. The SIMS analysis shows that the diffusion of Zn atoms into the HfO2 will occur after 300 oC annealing and the related electrical characteristics indicates that the 200 oC annealing will be the optimized annealing condition for the ZnO/HfO2/ITO based TFTs. The ZnO TFTs after optimized annealing condition exhibited transistor behavior over the range 0-7 V; the field effect mobility, subthreshold slope and on/off ratio were measured to be 1.3 cm2V-1s-1, 0.5 V/decade and ~106, respectively.
Effect of Passivation Layer on the Reliability of Flexible a-Si:H TFTs
Authors: Chou Yi-Teh , Liu Po-Tsun , Tsai Shang-Yao , Su Chih-Yu , Peng I-Hsuan
Published: October 2008

We investigated the stability of a-Si:H TFTs under mechanical strain with and without silicon nitride (SiNx:H) passivation. The process temperature of these flexibledevice, including the passivation layer, was well-controlled below 200°, and the substrate was using stainless steel foil. The strain stress was applied cylindrically parallel to the active channel path of TFTs. The stability measurement was performed by DC gate bias stress and lasted up to 104 seconds. By using electrical parameter fitting, the Vth metastability mechanism was dominated by state creation effect. Our result indicated the device with passivation layer was improved, and the Vth had less variation under both outward and inward bending. By exerting 190° post-annealing process after SiNx:H deposited, the Vth was shifted left and the reliability of flexible TFTs became better than without post-annealing process. That's related to the passivating effect of hydrogen ion under passivation layer and post-annealing process.
Development of Integrated Electronics on Silicon-on-Glass (SiOG) Substrate
Authors: Manley Robert , Fenger Germain , Meller Patricia , Hirschman Karl , Kosik Williams Carlo A. , Dawson-Elli David , Couillard J. Gregory , Cites Jeffrey
Published: October 2008

Development of integrated electronics on the silicon-on-glass (SiOG) substrate is presented. The SiOG material technology, under development by Corning Incorporated, consists of anodic bonding and an implant-induced separation to transfer a single crystalline silicon film onto a glass substrate. The silicon-glass interface region is characterized by an ultra-strong and thermally stable bond, and includes an in situ barrier layer that is free of mobile ions. Key aspects of the low temperature (< 600 {degree sign}C) CMOS device fabrication process are described, with an emphasis on the design tradeoffs involved to maintain process simplicity (i.e. 6-level mask count, and no VT adjustment). The discussion also provides specific details of the device structure and operation, including mechanisms that compromise device performance identified through electrical simulation.
Compensation Pixel Circuit Using LTPS TFT For AMOLED Displays
Authors: Liu Po-Tsun , Chu Li-Wei , Huang Yi-Lin
Published: October 2008

We propose a new 4T1C active-matrix organic light-emitting diode displays (AMOLEDs) pixel circuit using LTPS thin-film transistors is verified by SPICE simulation successfully. The pixel design compensates the variation of threshold voltage between 1 ~ -1V with 1.6% current non-uniformity. Besides, a proposed new external driving method and we combine power & data line for driving can reduce the number of switch transistors in a pixel and circuit complexity.
Screen-printed Algal Biosensor with Flow Injection Analysis System for Toxicity Test
Authors: Shitanda Isao , Takamatsu Satoshi , Itagaki Masayuki , Watanabe Kunihiro
Published: October 2008

A screen-printing algal biosensor was fabricated for a toxicity test. An algal ink was prepared by mixing algal cells, carbon nanotube and sodium alginate solution. The algal ink was printed on the carbon electrode surface using screen printing technique. The electrode was immersed in CaCl2 solution for gelation. Photosynthetically generated oxygen of the immobilized algae was monitored amperometically. Responses of the algal biosensor to a toxic compound, 6-chloro-N-ethyl-N-isopropyl-1,3,5-triazine-2,4 diamine (atrazine) were evaluated as inhibition ratios of the reduction current.
Immunoassay for Insulin Using Highly-Sensitive Hydrogen Peroxide Sensors Based on Charge Accumulation Systems
Authors: Yasukawa Tomoyuki , Ohta Eiji , Mie Yasuhiro , Niwa Osamu , Mizutani F.
Published: October 2008

A coulometric signal accumulation system to detect a trace concentration of hydrogen peroxide (H2O2) has been applied to develop a novel electrochemical enzyme immunosensing system for insulin, an important hormone for clinical diagnosis of diabetes. Glucose oxidase (GOx)-labeled anti-insulin IgG antibody was trapped on the substrate immobilized with insulin by an indirect competitive immunoassay. H2O2 generated by the enzymatic reaction with the trapped conjugate was detected by the coulometric signal accumulation system. The H2O2 generated oxidized [Os(bpy)2Cl]+ to [Os(bpy)2Cl]2+ in a horseradish peroxidase (HRP)-containing polymer layer on an electrode under the open-circuit condition, and then the [Os(bpy)2Cl]2+ accumulated was reduced by applying a negative potential. The accumulation brought about a large current response and a low detection limit for H2O2 (0.5 nM). The enhanced sensitivity for H2O2 enabled the determination of a trace concentration of insulin with the immunoassay using the antibody modified with GOx, a H2O2-producing enzyme.
Surface Plasmon Resonance (SPR) based Immunosensor for Sensitive Detection of Thyroxine
Authors: Kim Sook Jin , Dhesingh Ravi Shankaran , Kawaguchi Toshikazu , Miura Norio
Published: October 2008

Surface plasmon resonance (SPR) based immunosensor for rapid and sensitive determination of thyroxine (T4), which is one of major thyroid hormones, has been investigated. Here, a mixed self-assembled monolayer (SAM) of poly(ethylene) glycols (PEG) aromatic dialkanethiols was employed for fabricating sensor surface. As a methodology for low-molecular-weight (lmw) compounds, indirect inhibition that assures the detection of lmw analytes was used for sensitive detection of T4. With these methodologies, T4 could be detected down to 1 ppb (ng ml-1) level with the present SAM-based SPR immunosensor.
Simultaneous On-chip Surface Plasmon Resonance Measurement of Disease Marker Protein and Small Metabolite
Authors: Kurita Ryoji , Nakamoto Kohei , Sekioka Naoyuki , Niwa Osamu
Published: October 2008

Disease marker protein and a correction marker were simultaneously measured in a poly-dimethylsiloxane based microchannel. Two gold films in the microchannel were modified with antibody and redox polymer containing horseradish peroxidase (HRP). Creatininase, creatinase, and sarcosine oxidase were immobilized in the upstream. At first, marker protein and creatinine were simultaneously measured by surface plasmon resonance (SPR) and electrochemical methods, respectively. Then, we measured two analytes only by SPR method. We could measure glycoprotein, prostate specific antigen (PSA) (MW=33 kDa) and creatinine (MW= 113) both by SPR angle shifts caused by immuno- and redox reactions, indicating that urinary PSA concentration could be normalized with creatinine concentration by single injection.
Immuno-chromatographic Test-strip for Skin Cathepsin L Analysis
Authors: Yamaguchi Masaki , Kosaka Shoshi , Tahara Yusuke , Date Akira
Published: October 2008

The objective is to develop a methodology to analyze cathepsin L (Cat L) activity derived from the stratum corneum as an index of skin conditions. In this paper, a disposable type immuno-chromatographic test-strip (test-strip) is proposed for Cat L analysis. A fabricated test-strip for Cat L analysis consists of a sample pad, a conjugate pad, a nitrocellulose membrane and absorption pad. After dropping a sample, it was needed 90 s to reach the solution at the test-line on the test-strip. Three min after dropping, a reddish purple colored band was appeared as the test-line. The band visually observed clearly when the concentration of Cat L of the standard solution over 0.01 U/l. It was indicated a possibility of the disposable type immuno-chromatographic test-strip for the analysis of Cat L of skin.
Study of Ferrocene-modified G4 PAMAM Dendrimer for Reagentless Biosensor Develoment
Authors: Deriu Daniela , Favero Gabriele , D'Annibale Andrea , Mazzei Franco
Published: October 2008

A fourth generation amine-terminated dendrimer (G4-PAMAM) was chemically functionalized through ferrocene (Fc) tethered groups (length of tether = C11). The electrochemical properties of the new dendrimer molecule immobilized by using polyazetidine prepolymer (PAP) onto multi-walled carbon nanotubes (MWCNTs) screen printed electrode (SPE) surface, have been evaluated; then the Fc modified SPE was coupled to glucose oxidase (GOx) for the development of a reagentless glucose biosensor. The analytical performances of this device has been studied providing a linear response for one decade in the range 0.7 - 7.0 mM glucose with an RSD always below 4 %.
Highly Sensitive Detection of Influenza Virus Hemagglutinin by Electrochemiluminescence Using Immunoliposome
Authors: Egashira Naoyoshi , Morita Shin-ichi , Mitoma Yoshiharu , Hifumi Emi , Uda Taizo
Published: October 2008

An immunoliposome encapsulating a Ru complex with two aminopropyl moieties was prepared to rapidly detect the hemagglutinin (HA) protein of influenza virus. Under optimal conditions, the electrochemiluminescence method using the liposome gave a calibration curve that enabled to detect 3 x 10-13 g/mL of the HA. Alternatively, the method using Ru complex-labeled antibody can detect 1 x 10-8 ng/mL HA and the sensitivity was far lower than that of the above method.
Centrifugal Flow Device for High-throughput Detection of Cancer Marker CEA
Authors: Matsunaga Nobuyuki , Furutani Shunsuke , Kubo Izumi
Published: October 2008

A centrifugal flow disk was developed to allow the evaluation of cancer marker. Carcinoembryonic antigen (CEA), which is a major marker of cancer, was measured by an enzyme-linked immuno sorbent assay (ELISA) on the centrifugal flow disk. In this study we developed a rapid and sensitive assay system of the high-throughput detection of cancer marker. Anti CEA mouse monoclonal antibody was immobilized on micro beads. Micro chambers on the disk were filled with antibody-immobilized micro beads. The amount of the beads was 0.5 - 1 x 104 in one chamber. Sample solution containing CEA was applied to the micro chamber and the second antibody conjugated with HRP was applied. By the detection of chemiluminescence of the HRP reaction, the dynamic range of CEA determination was 0.0072 to 0.18 ng/ml with the use of 1 x 104 beads. The detection could be completed within 30 min.
Measurement of Endocrine Disruptors in Plastic Container (Styrofoam) by Capillary Electrophoresis Amperometric Method
Authors: Ha Kon , Joo Gi-sung , Jha Sandeep Kumar , Lee Hyun Ho , Yoon Tae-Sik , Kim Yong-Sang
Published: October 2008

A capillary electrophoresis amperometric detector was fabricated using Prussian blue (PB) modified indium tin oxide (ITO) electrode and twisted micro-channel configuration. These devices were used for detection of endocrine disruptors, such as bisphenol A (BPA) and butylphenol after their effective separation in microchannel. The microchip could detect as low as 1 µM of test analyte. This approach was further applied in detection of these contaminants in Styrofoam food container used in many East Asian countries for packaging of instant noodle, a popular fast food.
Voltammetry of the Pb/Pb2+ Redox Couple using a Gold Microcantilever Electrode
Authors: Bange Adam F. , Brown Gilbert , Senesac Larry R. , Thundat Thomas G.
Published: October 2008

Microfabricated silicon microcantilevers were coated with gold on one side and wired to a potentiostat so that electrochemical measurements could be made using the cantilever surface as an electrode. The microcantilever bending was measured optically as the surface potential was scanned and electrochemical reactions occurred on the surface. The microcantilever bending due to differential surface stress was used to sense Pb(II) using cyclic voltammetry (CV) and linear sweep stripping voltammetry (LSSV).
Mass Sensitive, Lorentz-Force Actuated, MEMS Preconcentrator and Chemical Sensor
Authors: Manginell Ronald P. , Adkins Douglas , Moorman Matthew , Hadizadeh Rameen , Copic Davor , Porter Daniel , Anderson John , Wheeler David , Pfeifer Kent , Rumpf Art
Published: October 2008

The mass-sensitive smart preconcentrator (SPC) consists of a Lorentz-Force-actuated MEMS resonator with an integral heater and surface coating for the collection of chemical analytes. Control circuitry is used to drive the SPC to resonance and measure its oscillation frequency. The frequency shift produced by adsorption of analyte on the SPC surface is inversely proportional to the mass of analyte collected. Thus, the SPC can measure when it has collected sufficient analyte for a downstream detection system. The limit of detection (LOD) of the SPC is less than 50 ppb for DMMP (dimethyl-methyl-phosphonate). At 1 ppm, less than 1 second collection of DMMP is sufficient to trigger analysis. An analytical model of operation of the SPC is used to predict the motion of the paddle and the shear modulus of silicon.
A Novel Microfluidic Whole Cell Biosensor Based on Electrochemical Detection for Water Toxicity Analysis
Authors: Ben-Yoav Hadar , Shacham-Diamand Yosi , Freeman Amihai , Biran Alva , Pedahzur Rami , Belkin Shimshon , Buchinger Sebastian , Reifferscheid Georg
Published: October 2008

Over the last few years, the physical dimensions of microchip devices have decreased, enhancing the interest in the integration of various devices and complex operations onto a compatible "lab on a chip" system with desirable characteristics and capabilities. This work presents a novel µ-fluidics whole cell biosensor for water toxicity analysis. The biosensor is based on bacterial cells genetically "tailored" to generate an electrochemical bio-signal in the presence of toxic materials. The µ-chip was electrochemically characterized, and demonstrated the potential toxicity analysis with a model toxicant. A novel concept of bacterial biosensors deposition by means of electrophoretic force was examined for the first time. Preliminary results demonstrated the ability to detect electrochemical signal generated by the deposited bacterial cells indicating the potential use for patterning of bacterial cells on solid-state surfaces for the use in bio-sensing.
Advanced Conductivity Detection for Microfluidics
Authors: Hoffmann Werner E. , Muehlberger Holger , Hwang Wonhee , Petrova Ludmila P. , Mootz Torsten , Saumer Monika , Guber Andreas E. , Saile Volker
Published: October 2008

The renaissance of the traditional contactless conductivity detec-tion (CCD) for ion analysis by transferring its principle to microchips for modern lab-on-a-chip applications is calling for further improvements to make use of all its inherent advantages. This contribution summarizes some progress in basic understanding, technological development and extended application.
Topographic Effects of Microstructured Biosensors
Authors: Wanzenboeck Heinz D. , Forouzan Sahar , Bertagnolli Emmerich , Guell Iris , Wirth Michael , Gabor Franz
Published: October 2008

Biosensors utilizing whole, living cells often rely on the adhesion of cells to the sensor surface. The effect of microstructures on human epithelial cells has been investigated. Microstructures were fabricated in a silicon substrate utilizing optical lithography and deep reactive ion etching. Human colon carcinoma cells (Caco-2) as used in pharmacological transport studies were grown on top of the microstructured substrates. A tendency of cells to adhere to edges was observed. Experimental data indicates, that cells are capable of bridging gaps. The influence of microstructure geometry on the proliferation rates of cells is discussed.
Development of Microelectrodes for Integrated CMOS Chemical Sensors
Authors: Cao Feifei , Greve David , Oppenheim Irving
Published: October 2008

Measurements of chlorine concentration are very important in municipal water systems. We report here on our progress toward the fabrication and testing of microelectrodes for chlorine sensing. We designed a three-electrode cyclic voltammetry test system and studied the performance of electrodes with different sizes and at different scan rates. Cyclic voltammograms from the test are analyzed. The further application of the microelectrodes for integrated CMOS sensors is discussed.
Measurement of Total Concentration of Hydrocarbon by Using Zirconia-based Sensor Attached with ZnCr2O4 Sensing-Electrode
Authors: Fujio Yuki , Plashnitsa Vladimir , Elumalai Perumal , Miura Norio
Published: October 2008

A mixed-potential-type sensor was fabricated by using yttria-stabilized zirconia (YSZ) and various zinc-based oxide sensing-electrodes (SEs) aiming at detection of hydrocarbons (HCs) in automobile exhausts. Among the various zinc-based oxide-SEs examined, ZnCr2O4 was found to give highly selective and sensitive response to C3H6 (propene) at 550oC even in the presence of 5 vol.% H2O. The Δemf (electromotive force) of the sensor showed almost linear dependence with the logarithm of C3H6 concentration. The sensitivity to 100 ppm C3H6 was found to hardly affect by the change in concentration of water vapor or O2. In addition, it was found that the sensitivity of the present sensor varied linearly with the carbon number of various HCs examined.
High Temperature Mixed-potential-type Ammonia Sensor Using Stabilized Zirconia and Oxide-based Sensing Electrode
Authors: Elumalai Perumal , Plashnitsa Vladimir , Fujio Yuki , Miura Norio
Published: October 2008

A mixed-potential-type planar sensor using yttria-stabilized zirconia (YSZ) and oxide-based sensing-electrode (SE) was fabricated and examined for detection of NH3 at high temperature. It was found that the sensor attached with NiO/Au-SE exhibited good sensitivity and excellent selectivity to NH3 at 800oC under the wet condition (5 vol.% H2O). While the cross sensitivities to the other examined gases were about {plus minus}5 mV or negligible, the sensitivity to 100 ppm NH3 was about -34 mV. The Δemf of the sensor varied almost linearly with the NH3 concentration in the examined range of 20-100 ppm. The stability of the sensor response was found to be quite stable for the test period of about 50 days.
Development of a Zirconia-Based Electrochemical Sensor for the Detection of Hydrogen in Air
Authors: Brosha Eric L. , Mukundan R. , Lujan Roger , Garzon Fernando H.
Published: October 2008

Mixed potential sensors utilizing a machined, dense indium-tin oxide working electrode (In2O3:SnO2; 90%:10%), a Pt wire counter electrode, and porous YSZ electrolyte were prepared using ceramic tape casting methods. The response of these devices to hydrogen concentrations up to 2% in air were studied from 600 to 740{degree sign}C. The sensor response exhibited a reversible behavior and a fast response time with sensitivity increasing with decreasing temperature. GC analysis confirmed significant heterogeneous oxidation of the H2 on heated furnace tube wall surfaces thus driving sensor response at H2 concentrations greater than a few hundred ppm. The transition to a cold wall, miniature platform heater significantly reduced hydrogen oxidation although some flow rate dependence remains.
Zeolite Modified Discriminating Gas Sensors
Authors: Binions Russell , Davis Helen , Afonja Ayo , Dungey Sheena , Lewis Dewi , Williams David , Parkin Ivan
Published: October 2008

The use of zeolites to enhance the response and discriminating power of solid state metal oxide semiconductor gas sensors is demonstrated. Thick film sensors were prepared by screen printing layers of tungsten trioxide (WO3) or chromium titanium oxide (CTO) with various zeolites as over-layers. The sensors' gas response was tested against carbon monoxide and ethanol in varying concentrations. The results show that in some cases the gas response is greatly enhanced and in other cases diminished; discriminatory behaviour that will be useful in electronic noses.
Hydrogen Sensing Properties of an Anodized TiO2 Film Equipped with a Pd-Pt Electrode
Authors: Nakaoka Masaki , Hyodo Takeo , Shimizu Yasuhiro , Egashira Makoto
Published: October 2008

An anodized TiO2 sensor equipped with a Pd-Pt electrode was subjected to heat treatment in air (air-treated) and additionally in N2 (N2-treated), and then its responses to H2 balanced with air or N2 were investigated under dry and wet conditions. Among the conditions tested, the N2-treated sensor showed the largest H2 response in dry N2 atmosphere. But, H2 response of the air-treated sensor increased with the existence of water vapor, while that of the N2-treated sensor decreased with the existence of water vapor. As a result, H2 response of the air-treated sensor in wet air was quite comparable with that of the N2-treated sensor in wet N2. Thus, it was revealed that the existence of water vapor reduced the pretreatment- and measurement atmosphere-dependent H2 response of the sensor.
Detection of SO2 at High Temperature with Electrically Biased, Solid-Electrolyte Sensing Elements
Authors: West David , Montgomery Fred , Armstrong Tim
Published: October 2008

Design and operation of sensing elements for the detection of sulfur dioxide (SO2) at high temperature (800-900 oC) is described. The sensing elements consisted of three (two oxide and one Pt) electrodes on yttria-stabilized zirconia substrates. To operate the elements, a constant current (usually on the order of 0.1 mA) was driven between two of the electrodes and the voltage between one of these electrodes and the third electrode was monitored and used as the sensing signal. In one example, 31 ppm SO2 caused an approximately 40% change in the element output, and 2 ppm of SO2 could be easily detected. The cross-sensitivity to several interferents such as NOx was evaluated and found to be relatively small in comparison to the SO2 response.
Sulfur Dioxide Gas Sensor Based on Al3+ and O2- Ion Conducting Solid Electrolytes
Authors: Tamura Shinji , Nagai Tsukasa , Inaba Yuichi , Imanaka Nobuhito
Published: October 2008

A new solid electrolyte type sulfur dioxide (SO2) gas sensor was developed by the combination of trivalent Al3+ ion conducting (Al0.2Zr0.8)20/19Nb(PO4)3 solid and divalent O2- ion conducting yttria stabilized zirconia (YSZ) with 0.8Gd2O2SO4-0.2NaAl(SO4)2 as an auxiliary sensing electrode. Since the present sensor exhibited such a superior sensing performance of continuous and rapid response obeying the theoretical Nernst relationship, it is greatly expected to be a practical SO2 gas sensing device.
Odor Source Localization for Early Fire Detection by using MOS-type Gas Sensor Array with Infrared Vision
Authors: Takei Yoshinori , Fuma Toru , Kawai Hiroyuki , Uneda Michio , Nanto Hidehito , Koyama Shin
Published: October 2008

This paper shows that a mobile robot for odor source localization toward early stage fire detecting is demonstrated. The odor source localization system is developed by using an arrayed metal oxide semiconductor (MOS)-type gas sensors. The system can track a plume generated by the odor source. Furthermore, for early stage of fire detection, heat source detection is investigated by using a CMOS camera with an infrared pass filter. We will show that the developed sensing system can work to guide the robot to the odor source.
Smart Sensor Systems for Aerospace Applications: From Sensor Development to Application Testing
Authors: Hunter G. , Xu J. , Dungan L. , Ward B. , Rowe S. , Williams J. , Makel D. B. , Liu Chung-Chiun , Chang C.
Published: October 2008

The application of Smart Sensor Systems for aerospace applica-tions is a multidisciplinary process consisting of sensor element development, element integration into Smart Sensor hardware, and testing of the resulting sensor systems in application environments. This paper provides a cross-section of these activities for multiple aerospace applications illustrating the technology challenges in-volved. The development and application testing topics discussed are: 1) The broadening of sensitivity and operational range of sili-con carbide (SiC) Schottky gas sensor elements; 2) Integration of fire detection sensor technology into a "Lick and Stick" Smart Sensor hardware platform for Crew Exploration Vehicle applica-tions; 3) Extended testing for zirconia based oxygen sensors in the basic "Lick and Stick" platform for environmental monitoring ap-plications. It is concluded that that both core sensor platform tech-nology and a basic hardware platform can enhance the viability of implementing smart sensor systems in aerospace applications.
Chemical Threat Point Sensors Based on Infrared Spectrophotometry and Adsorptive Preconcentrators
Authors: Carter M. , Marotta Christopher , Trimboli Joseph , Pierce Michael
Published: October 2008

This paper reports progress toward development of a field-deployable monitor for detecting chemical threats such as chemical warfare agents (CWAs) and toxic industrial chemicals (TICs) by their infrared (IR) spectrochemical signature. Our work has focused on development of the chemical sensor, particularly of adsorbent media for preconcentration of low concentrations of threat vapors. We prepared and tested a wide variety of fluorinated epoxy polymer films to evaluate the effects of film properties on preconcentration, response time and stability. We also identified several inorganic adsorption layers which we found to have dramatically different interactions with the DMMP compared to the polymers.
Development of Electrochemical Blister Agent Sensor Using Carbon Fiber or Paper Electrode Modified with Au Nano Particles
Authors: Nishiyama Katsuhiko , Yamada Hiroyuki , Matsuura Hiroaki , Asada Ryuji , Nakano Nobuo , Seto Yasuo , Taniguchi Isao
Published: October 2008

We report that an electrochemical sensor to detect blister agents such as mustard gas (HD) using the carbon electrode modified with gold nanoparticles. Carbon fiber or carbon paper electrode modified with Au nanoparticles showed relatively high sensitivity for HD and the sensitivity of the sensor depended on the kind of carbon materials, the amount of modified gold, and the electrode potential. The linear relationship of the current vs. [HD] was obtained with the range from 1 to 9.6 mg m-3 of HD. By using the sensor prepared in this study, we can detect 1.5 mg m-3 of [HD], which is required concentration for a mobile gas sensor.
Fabrication of Poly-Silicon Sensor Device and Its Application to Ammonia Detection
Authors: Wu Cheng-Yen , Chou Yen-I , Lai Shih-Ming
Published: October 2008

In this study, the solid-state ammonia sensor based on poly-Si resistance wire was newly developed and preliminarily characterized. Experimental results showed that the poly-Si ammonia sensor exhibited the superior and reliable ammonia sensing performance in the concentration range from 5 to 500 ppm at low temperatures within 50-100 oC.
Organic Molecular Sensor with Plasmon Antenna
Authors: Yanagisawa Masahiro , Shimamoto Naonobu , Nakanishi Takuya , Saito Mikiko , Osaka Tetsuya
Published: October 2008

An organic molecular sensor with a plasmon antenna was developed. A coaxial Ag grating antenna was designed by a finite differential time domain (FDTD) calculation and fabricated by a lift-off process. When pumping light was irradiated onto the sensor, a surface plasmon wave was generated and focused at the center of the antenna; this wave produced a strong electric field. By coating a cystamine self-assembled monolayer (SAM) onto the sensor, strong Raman scattering light produced by a surface-enhanced Raman scattering (SERS) effect was observed at the center of the device. The Raman spectrum showed good agreement with that of cystamine on a Ag surface. The Raman intensity at the center of the device increased significantly and was more than 2,000 times that outside the device. Our optical sensor can detect an unknown single molecule and can be incorporated into other sensors such as gas sensors and biosensors.