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Photoacoustic spectroscopy has been shown to be a promising tool for non-invasive blood glucose monitoring. However, the repeatability of such a method is susceptible to changes in skin condition, which is dependent on hand washing and drying due to the high absorption of infrared excitation light to the skin secretion products or water. In this paper, we present a method to meet the challenges of mid-infrared photoacoustic spectroscopy for non-invasive glucose monitoring. By obtaining the microscopic spatial information of skin during the spectroscopy measurement, the skin region where the infrared spectra is insensitive to skin condition can be locally selected, which enables reliable prediction of the blood glucose level from the photoacoustic spectroscopy signals. Our raster-scan imaging showed that the skin condition for in vivo spectroscopic glucose monitoring had significant inhomogeneities and large variability in the probing area where the signal was acquired. However, the selective localization of the probing led to a reduction in the effects of variability due to the skin secretion product. Looking forward, this technology has broader applications not only in continuous glucose monitoring for diabetic patient care, but in forensic science, the diagnosis of malfunctioning sweat pores, and the discrimination of tumors extracted via biopsy.

Current biometrics rely on images obtained from the structural information of physiological characteristics, which is inherently a fatal problem of being vulnerable to spoofing. Here, we studied personal identification using the frequency-domain information based on human body vibration. We developed a bioacoustic frequency spectroscopy system and applied it to the fingers to obtain information on the anatomy, biomechanics, and biomaterial properties of the tissues. As a result, modulated microvibrations propagated through our body could capture a unique spectral trait of a person and the biomechanical transfer characteristics persisted for two months and resulted in 97.16% accuracy of identity authentication in 41 subjects. Ultimately, our method not only eliminates the practical means of creating fake copies of the relevant characteristics but also provides reliable features.

We present a novel biometric authentication system enabled by ratiometric analysis of impedance of fingers. In comparison to the traditional biometrics that relies on acquired images of structural information of physiological characteristics, our biological impedance approach not only eliminates any practical means of making fake copies of the relevant physiological traits but also provides reliable features of biometrics using the ratiometric impedance of fingers. This study shows that the ratiometric features of the impedance of fingers in 10 different pairs using 5 electrodes at the fingertips can reduce the variation due to undesirable factors such as temperature and day-to-day physiological variations. By calculating the ratio of impedances, the difference between individual subjects was amplified and the spectral patterns were diversified. Overall, our ratiometric analysis of impedance improved the classification accuracy of 41 subjects and reduced the error rate of classification from 29.32% to 5.86% (by a factor of 5).

We have developed an enhanced sandwich immunogold assay for highly sensitive detection of cardiac troponin I (cTnI) in human serum. In this assay, the immunoreaction undergoes in sample solution between cTnI antigen and gold nanoparticles conjugated with detection antibodies of cTnI (immunogolds). Then, a capture antibody of cTnI immobilized on a standard 96-well plate captures the immunogold complex, followed by silver staining of the immunogold for the purpose of signal amplification. Compared to the direct assay where the immunoreaction occurs between the target and the capture antibody coated on the well, we found the enhanced assay shows greatly improved sensitivity by two orders of magnitude and a linear relation of the quantitative plot. Because the immunogold concentration affect greatly the sensitivity of the cTnI detection, we also studied the performance of direct and enhanced immunogold assay depending on the concentration of immunogold conjugates. By using the enhanced assay with the optimized procedure, we could achieve the detection of cTnI in human serum as low as 15 pg/mL. We also verified the enhanced immunogold assay by measuring the concentration of clinical samples for a healthy person and patients. This development can allow us to apply the assay not only for the analysis of other cardiac markers as well as disease-related biomarkers but also for the optimization of other chip-based silver enhanced colorimetric sensors.

An Nd:YAG laser is generally used as the optical source for photoacoustic imaging (PAI) systems, which support a high-power pulsed laser. However, PAI systems based on Nd:YAG lasers have several disadvantages, such as instability against impact and vibration, poor mobility, and large size. To overcome the limitations, we demonstrate a PAI system using a master oscillator power amplifier (MOPA) fiber laser and an arrayed ultrasound transducer. The fabricated MOPA fiber laser has a variable repetition rate in the range of 1–50 kHz, a pulse width of 10–70 ns, and an output power of 160 μJ. Furthermore, it is stable to impact and vibration, mobile, and compact with a size of 427×250×170 mm3. We achieved PAI 150 times faster using MOPA fiber laser than using Nd:YAG laser with the arrayed ultrasound transducer composed of 128 elements. Therefore, we believe that the PAI system based on the MOPA fiber laser has significant potential for use as a clinical ultrasound imaging system.

Glucose measurements using photoacoustic spectroscopy have been highlighted to be a modality for non-invasive glucose monitoring. Previous photoacoustic spectroscopy for glucose measurements have used a resonant acoustic cell with a broadband capacitive microphone to increase sensitivity. However, a resonant characteristic of a microphone has not been investigated yet due to the working frequency range much lower than the resonance frequency of the microphone membrane. We, here, present a photoacoustic spectroscopy system that utilizes an ultrasound resonance of a microphone to increase sensitivity. We found that matching the resonance of a photoacoustic cell with the resonance of a microphone can increase signal-to-noise ratio and our system can distinguish the glucose concentration in liquid.

Gas-sensor array technology, which has been much utilized in the field of food technology by the name of 'electronic nose' is drawing attention in diagnosing lung cancer based on the analysis of the exhaled human breath. Much understanding has been accomplished about the composition of the volatile organic compounds (VOCs) of the human exhaled breath, in spite of some variations depending on research groups due mainly to lack of the standardization of the sensing procedures. Since VOCs may be produced during the process of cellular metabolism, difference in the cellular metabolism between healthy cells and lung cancer cells are expected to be reflected on the composition variation of the exhaled VOCs. Several studies have attempted to apply the gas-sensor array technology to lung cancer analysis using many different types of sensors including metal oxide, carbon black-polymer composite, surface acoustic wave, and gold nanoparticles. In this mini-review VOC as biomarkers, sensor array technology and application of the array technology for the diagnosis of cancer disease have been described.

Complementary metal oxide semiconductor (CMOS)-based image sensors have received increased attention owing to the possibility of incorporating them into portable diagnostic devices. The present research examined the efficiency and sensitivity of a CMOS image sensor for the detection of antigen-antibody interactions involving interferon gamma protein without the aid of expensive instruments. The highest detection sensitivity of about 1 fg/ml primary antibody was achieved simply by a transmission mechanism. When photons are prevented from hitting the sensor surface, a reduction in digital output occurs in which the number of photons hitting the sensor surface is approximately proportional to the digital number. Nanoscale variation in substrate thickness after protein binding can be detected with high sensitivity by the CMOS image sensor. Therefore, this technique can be easily applied to smartphones or any clinical diagnostic devices for the detection of several biological entities, with high impact on the development of point-of-care applications.

We demonstrate the application of ‘top-down’ fabricated Si nanochannel field effect transistor biosensors in measuring the configuration of charged proteins immobilized on the Si surface. We have immobilized monoclonal antibodies of PSA (anti-PSA) on the p-type Si channel surface, and monitored the channel conductance in response to the variation of ionic strength (salt concentration) and pH level of the buffer solution. The dependency of channel conductance on the salt concentration is consistent with the screening of protein charges by dissolved counterions, enabling quantitative estimation of the distance from the Si surface to anti-PSA molecules based on calculated Debye screening lengths (λD) for each salt concentration. The effect of salt concentration on the pH-dependency of channel conductance has also been studied, and explained in terms of the net charge of anti-PSA as a function of pH.

In this study, we have developed a new detection method using Si field effect transistor (FET)-type biosensors, which enables the direct monitoring of antigen-antibody binding within very high-ionic-strength solutions such as 1×PBS and human serum. In the new method, as no additional dilution or desalting processes are required, the FET-type biosensors can be more suitable for ultrasensitive and real-time analysis of raw sample solutions. The new detection scheme is based on the observation that the strength of antigen-antibody-specific binding is significantly influenced by the ionic strength of the reaction solutions. For a prostate specific antigen (PSA), in some conditions, the binding reaction between PSA and anti-PSA in a low-ionic strength reaction solution such as 10 µM phosphate buffer is weak (reversible), while that in high-ionic strength reaction solutions such as 1×PBS or human serum is strong.

In order to identify changes in the levels of key proteins in response to the onset or development of a disease, the research fields of proteomics and genomics seek to develop new biomarkers. Specifically, simple and fast biomarker screens have a central role in many areas of healthcare, including disease diagnosis and drug discovery. Biologically modified field-effect transistor (BioFET) is one of the most attractive approaches because of the on-chip integration of the sensor array, fast response, high reliability and low-cost mass production. However, the BioFETs used to detect macromolecules have been operated only in buffer solution with low salt concentrations because of the Debye screening length of blood or serum. Here we report a novel detection technique for direct label-free immunodetection of cancer markers in human serum using a Si-FET that was fabricated by conventional photolithographic processes. The proposed sensing method shows no dissociation of antigen-antibody binding as in general immunoassays, unlike the previous reports on Si-FET sensors. This method therefore overcomes the Debye length problem of immunodetection in human fluids, such as serum, that are generally encountered by FET-based biosensors. Our results demonstrate specific label-free and real-time immunodetection of a cancer marker at a concentration of 0.2 ng/mL in human serum, quantitative detection of the marker from 0.2 to 114 ng/mL, and successful multiplexed sensing of three different cancer markers. We believe that connecting our simple electrical detection method, which does not require pretreatment of serum, with well-established whole blood filter technology will contribute to the development of new point-of-care testing (POCT) sensors.

High-performance three-dimensional (3-D) stacked poly-Si complementary metal-oxidesemiconductor (CMOS) inverters with a high-quality laser-crystallized channel were fabricated. Lowtemperature crystallization methods of an a-Si lm using excimer-laser annealing (ELA) and sequential lateral solidi cation (SLS) were performed. The n-channel metal-oxide-semiconductor (NMOS) thinlm transistors (TFT) at the lower CMOS layer were fabricated on an oxidized bulk Si substrate and p-channel metal-oxide semiconductor (PMOS) TFT at the upper CMOS layer were fabricated on an interlayer dielectric lm. Considerably uniform silicon grains were obtained by laser annealing. Sub-threshold swings of the fabricated NMOS TFTs at the lower layer and PMOS TFTs at the upper layer were 78 mV/dec. and 86 mV/dec., respectively. The eld e ect mobilities of the NMOS and the PMOS TFTs were 42.5 cm2/V s and 76 cm2/V s, respectively. The on/o current ratio of both TFTs was larger than 107. 3-D stacked poly-Si CMOS inverter showed excellent electrical characteristics and can be used the vertical integrated CMOS applications.

In this paper, a Schottky barrier polycrystalline silicon thin-film transistor (SB TFT) with erbium silicide source/drain is demonstrated using low temperature processes. A low temperature oxide is used for a gate dielectric and the transistor channel is crystallized by a metal-induced lateral crystallization process. An n-type SB TFT shows a normal electrical performance with subthreshold slope of 239 mV/dec, ION/IOFF ratio of 5.8 × 104 and ION of 2 μA/µm at VG = 3 V, VD = 2.5 V for 0.1 μm device. A process temperature is maintained at less than 600 °C throughout the whole processes. The SB TFT is expected to be a promising candidate for a next system-on-glass technology and an alternative 3D integration technology.

Three-dimensionally stacked CMOS inverters were fabricated by using the poly-Si thin film transistor (TFT) with hafnium-oxide (HfO"2) gate dielectric and Pt gate electrode. For fabrication of 3-D stacked CMOS inverters consist of poly-Si NMOS/interlayer dielectric film (ILD)/poly-Si PMOS, a reduced process temperature is necessary to avoid the degradation of NMOS at lower poly-Si layer fabricated prior to PMOS at upper poly-Si layer. The high quality of laser crystallized poly-Si film was obtained with smooth surface and excellent crystallinity. The 3-D stacked CMOS inverters fabricated by stacking the poly-Si NMOS TFT and PMOS TFT showed good output characteristics, DC voltage transfer characteristics, transient characteristics and voltage gain for applications of the vertical integrated CMOS circuits.

The fabrication methods and characteristics of polycrystalline silicon (poly-Si) thin film transistor (TFT) stacked complementary metal oxide semiconductor (CMOS) inverters were demonstrated the feasibility for high performance logic circuit applications was verified. The laser crystallization processes were compatible with the poly-Si TFT stacked CMOS inverters and the laser crystallized poly-Si films showed uniform grain size with low surface roughness and excellent crystallinity. In order to fabricate three-dimensional (3-D) stacked poly-Si CMOS inverters, the p-channel MOSTFTs (PMOS) at upper poly-Si layer were stacked on the n-channel MOSTFT (NMOS) at lower poly-Si and interlayer dielectric (ILD) layer. The HfO2 gate dielectrics and Pt metal gates were applied to the upper PMOSTFT to avoid the degradation of lower NMOSTFT. The CMOS inverters fabricated by stacking the poly-Si TFTs revealed good characteristics for the 3-D integrated CMOS applications.

3D stacked poly-Si CMOS inverters with a high quality laser crystallized channel were fabricated on bulk Si wafers. In order to fabricate 3D stacked poly-Si CMOS inverters, the PMOS thin-film-transistor (TFT) at upper poly-Si layer were stacked on the NMOS TFT at lower poly-Si layer and interlayer dielectric film. After laser crystallization, grains in poly-Si films were very uniform and the dominant crystalline orientation was (1 1 1) direction. The sub-threshold swing of NMOS and PMOS TFTs was very good, showing 78 mV/dec. and 86 mV/dec., respectively. And the maximum/minimum current ratio of both TFTs was larger than 10 7 which is equivalent to those at the bulk or SOI MOSFET. The DC voltage transfer characteristics and transient characteristics of stacked poly-Si CMOS inverter were good enough for the vertical integrated CMOS applications. We verified the feasibility of 3D stacked CMOS inverter circuit by poly-Si TFT technology.

Ultra shallow and abrupt n+–p junctions were formed on a silicon-on-insulator (SOI) using solid phase diffusion from arsenic-doped spin-on dopant source with various rapid thermal annealing (RTA) conditions. Their doping profiles and electrical characteristics were investigated and compared with those of junctions prepared from phosphorous-doped spin-on-dopant. Analysis of arsenic doped n+–p junctions prepared at the drive-in temperature of 950 °C revealed that the junction depth and junction abruptness are 27 nm and 8.5 nm/dec., respectively, which are superior to phosphorus-doped junctions. Moreover, the SOI n-type metal-oxide-semiconductor field effect transistor (MOSFET) with the gate length of 90 nm which source and drain extensions were doped from arsenic spin-on-dopant had good short channel properties.

For Si nanocrystals, which are formed by Si ion implantation into a SiO2 layer, the effects of crystal size and interface states on the photoluminescence property are investigated. The Si-implanted SiO2 samples are annealed in an N2 ambience at different temperatures to obtain Si nanocrystals of different sizes. The sample annealed at 1100°C shows a strong and broad photoluminescence (PL) peak at 700 nm (1.77 eV). The observed PL spectrum redshifts when the annealing temperature increases, blue shifts when the samples are oxidized, and redshifts followed by blue shifts when the average size of the Si nanocrystals increases and then decreases with etch depth of the SiO2 layer. Low-temperature annealing in an H2 ambience increases the PL intensity but does not change the PL spectral distribution. Experimental observations indicate that the size of the Si nanocrystal determines the quantum state for carrier excitation and that the interface states at the Si nanocrystal/SiO2 interface provide the nonradiative recombination centers.

We have successfully used hydrophobic direct wafer bonding along with hydrogen-induced layer splitting of germanium to transfer 700 nm thick, single-crystal germanium (100) films to silicon (100) substrates without using a metallic bonding layer. The metal-free nature of the bond makes the bonded wafers suitable for subsequent epitaxial growth of layered solar cells at high temperatures without concern about metal contamination of the device active region. Contact mode atomic force microscopy images of the transferred germanium surface generated by the formation of micro-bubbles and micro-cracks along the hydrogen-induced layer-splitting interface reveals minimum rms surface roughness of between 10 nm and 23 nm. Electrical measurements indicated ohmic I-V characteristics for germanium layers bonded to silicon substrates with ∼400 Ω cm−2 resistance at the interface. Triple-junction solar cell structures grown on these Ge/Si heterostructure templates by metal-organic chemical vapor deposition show comparable photoluminescence intensity and minority carrier lifetime to a control structure grown on bulk Ge. The use of a molecular beam epitaxy Ge buffer layer to smooth the cleaved surface of the Ge heterostructure has been shown to smooth the rms surface roughness from ∼11 nm to as low as 1.5 nm with a mesa-like morphology that has a top surface roughness of under 1.0 nm giving a promising surface for improved solar cell growth on solar cell structures.

We propose a compact and easy to use photoacoustic imaging (PAI) probe structure using a single strand of optical fiber and a beam combiner doubly reflecting acoustic waves for convenient detection of lymph nodes and cancers. Conventional PAI probes have difficulty detecting lymph nodes just beneath the skin or simultaneously investigating lymph nodes located in shallow as well as deep regions from skin without any supplementary material because the light and acoustic beams are intersecting obliquely in the probe. To overcome the limitations and improve their convenience, we propose a probe structure in which the illuminated light beam axis coincides with the axis of the ultrasound. The developed PAI probe was able to simultaneously achieve a wide range of images positioned from shallow to deep regions without the use of any supplementary material. Moreover, the proposed probe had low transmission losses for the light and acoustic beams. Therefore, the proposed PAI probe will be useful to easily detect lymph nodes and cancers in real clinical fields.

We propose an approach to match the resonant characteristics of a photoacoustic cell with that of a microphone in order to enhance the signal-to-noise ratio in the photoacoustic sensor system. The synergetic resonance matching of a photoacoustic cell and a microphone was achieved by observing that photoacoustic cell resonance is merged with microphone resonance, in addition to conducting numerical and analytical simulations. Using this approach, we show that the signal-to-noise ratio was increased 3.5-fold from the optimized to non-optimized cell in the photoacoustic spectroscopy system. The present work is expected to have a broad impact on a number of applications, from improving weak photoacoustic signals in photoacoustic spectroscopy to ameliorating various sensors that use acoustic resonant filters.

The present paper examines the efficiency of a complementary metal-oxide semiconductor (CMOS) using an indium nanoparticle (InNP) substrate for the high-sensitivity detection of antigen/antibody interactions at concentrations as low as 100 pg/ml under normal light. Metal NPs coated with antigen/antibody layers act as a dielectric layer on the conducting sphere, which enhances the number of photons hitting the sensor surface through a light-scattering effect. This photon number is proportional to the digital number observed with the CMOS sensor for detecting antigen/antibody interactions.

Energy-filtered reflection high energy electron diffraction and reflection electron energy loss spectroscopy expand the usefulness of reflection high energy electron diffraction for quantitative structure determination and surface spectroscopy during film growth. Several implementations of energy-filtered reflection high energy electron diffraction are discussed, along with the progress and prospects for structure determination. New developments in parallel detection reflection electron energy loss spectroscopy (PREELS) enable the use of this method to obtain surface-spectroscopic information in real time during thin film growth, greatly expanding the range of surface information available during growth.

Carbon incorporation in Si and SiGe heteroepitaxial structures offers exciting opportunities in the design of novel, Si-based electronics. Recent results suggest that in order to realize the potential of this material system, methods for achieving high carbon concentrations (in excess of 5 at.%) without sacrificing crystalline quality must be developed. We have investigated the use of Sb as a surfactant to assist in the incorporation of carbon during growth of Si and SiGe epitaxial layers by molecular beam epitaxy. For samples in which Sb is not used, reflection high-energy electron diffraction (RHEED) shows that the wafer surfaces roughen soon after the carbon is introduced. As growth proceeds, the layers eventually twin and become defective, especially for thicker layers and higher carbon concentrations (>2%). Roughening occurs at even lower carbon concentrations for the case of SiGeC growth as we have grown Si 1−x−y Ge x C y /Si 1−y ′ C y ′ heterostructures with y ′> y , and observe RHEED patterns are streaked during the Si 1−y ′ C y ′ deposition but spotted during the Si 1−x−y Ge x C y deposition. The presence of ≤1 monolayer of Sb on the surface of the substrate prior to epitaxy is shown in this work to substantially reduce roughening of the growth front, resulting in a dramatic reduction in defect density with minimal Sb incorporation ( 17 cm −3 ). Transmission electron microscopy and secondary ion mass spectrometry data relating to the quality of the layers and the amount of Sb incorporation will be discussed.

A novel ultrathin body SOI MOSFET with a recessed source-drain (S/D) structure is proposed to reduce the S/D extension (SDE) resistance and the feasibility on the proposed device is checked. A recessed buried oxide under the SDE regions is completely filled with the heavily doped polysilicon, which can lead to a low SDE resistance. A recessed S/D SOI MOSFET with 30 nm gate length and 5 nm thick undoped channel, was successfully fabricated and showed the good SCE immunities; little punch-through, the drain-induced barrier lowering of 140 mV/V, and the subthreshold slope of 79 mV/dec.

We have proposed the planar backing array electrodes implementation of a 2D ultrasonic transducer, which can minimize the complexity of backing electrodes interconnection with two dimensional transducer elements. The implementation consists of specially designed two layered planar top electrodes, instead of the complex circuit boards three-dimensionally interconnected with piezo-elements. Bias electrodes apply the voltage and control electrodes select the elements at which we want to apply the bias by shielding the field stretched on other elements. Potential distribution in a piezo-element was simulated to see the feasibility of the new concept using field shielding by two layered top electrodes array. The results indicate that the structural implementation of two layered electrode array is very important and specially designed two layered electrodes are enough to control the perfect ON/OFF state, showing that most of the voltage (>98%) applied across the sensor element can be shielded.

A plasma-doping technique for fabricating nanoscale silicon-on-insulator (SOI) MOSFETs has been investigated. The source/drain (S/D) extensions of the tri-gate structure SOI n-MOSFETs were formed by using an elevated temperature plasma-doping method. Even though the activation annealing after plasma doping was excluded to minimize the diffusion of dopants, which resulted in a laterally abrupt S/D junction, we obtained a low sheet resistance of 920 /spl Omega///spl square/ by the elevated temperature plasma doping of 527 /spl deg/C. A tri-gate structure silicon-on-insulator n-MOSFET with a gate length of 50 nm was successfully fabricated and revealed suppressed short-channel effects.

We present a novel blood filter device which is actuated by simple magnetic squeezing to layered membranes. The filter gives a good performance in high plasma recovery yield (∼25%), nearly-perfect filtering efficiency (∼100%), low blood consumption (

We propose a new type of photosensitive biosensor with a CMOS compatible Si photodiode integrated circuit, for the high-sensitive detection of small mycotoxin molecules requiring competitive assay approach. In this work, a photodiode is connected to the gate of a field effect transistor (FET) so that the open circuit voltage ( V OC ) of the illuminated photodiode is transferred into the drain/source current ( I DS ) of the FET. The sensing scheme employs competitive binding of toxin molecules (within the sample solution) and toxin–BSA conjugates (immobilized on the photodiode surface) with Au-nanoparticle-labeled antibodies, followed by silver enhancement to generate opaque structures on the photodiode surface. By utilizing the non-linear dependence of the V OC on the light intensity, we can maintain a sufficiently high signal resolution at low toxin concentrations (with most of the incident light blocked) for the competitive assay. By monitoring the I DS of the FET whose gate is driven by the V OC , quantitative detection of Aflatoxin B1 has been achieved in the range of 0–15 ppb.

The sensitivity of 'top-down' fabricated Si nanochannel field effect transistor (FET) biosensors has been analyzed quantitatively, as a function of the channel width and doping concentration. We have fabricated 130-, 150-, and 220 nm-wide Si FET channels with 40 nm-thick p-type silicon-on-insulator (SOI) layers doped at 8 x 10(17) and 2 x 10(18) cm(-3), and characterized their sensitivity in response to the variation of surface charges as hydrogen ion sensors within buffer solutions of various pH levels. Within the range of channel width and doping concentration investigated, the pH sensitivity of Si channels is enhanced much more effectively by decreasing the doping concentration than by reducing the channel width, which suggests a practical strategy for achieving high sensitivity with less effort than to reduce the channel width. Similar behavior has also been confirmed in the immunodetection of prostate specific antigen (PSA). Combined with excellent reproducibility and uniformity of the channel structure, high controllability of the doping concentration can make the 'top-down' fabrication a very useful approach for the massive fabrication of high-sensitivity sensor platforms in a cost-effective way.

Modified ISFETs having an extended gate on the thick dielectric has been developed to obtain the extremely high sensitivity. The capacitance of the extended gate is controlled to be very small via the thickness of the insulator layer so that it may be ignored when compared with the gate capacitance of the transistor. As the result, the gate voltage may be fully dependent on the surface charge of the extended gate. The surface immobilization of the monoclonal antibody of microalbumin (mab-MA) on the extended gate is confirmed by the specific binding test of modified Au nanoparticles (NPs), resulting in a high density Au nanoparticles of about 800 NPs/um 2 . When the microalbumin protein of 1 ng/ml on the mab-MA surface of the extended gate is injected, the extremely high sensitivity of 1800% is observed.

We report the strong visible light emission from silicon (Si) nanocrystals (NCs) embedded in a Si carbide (SiC) film. Compared to Si NC light-emitting diode (LED) by employing the Si nitride (SiNx) film as a surrounding matrix, the turn-on voltage of the Si NC LED with the SiC film was significantly decreased by 4 V. This was attributed to a smaller barrier height for injecting the electrons into the Si NCs due to a smaller band gap of SiC film than a SiNx film. The electroluminescence spectra increases with increasing forward voltage, indicating that the electrons are efficiently injected into the Si NCs in the SiC film. The light output power shows a linear increase with increasing forward voltage. The light emission originated from the Si NCs in a SiC film was quite uniform. The power efficiency of the Si NC LED with the SiC film was 1.56 times larger than that of the Si NC LED with the SiNx film. The Si NCs in a SiC film show unique advantages and are a promising candidate for application in optical d...

The effect of rapid thermal annealing (RTA) and post-RTA annealing (PRA) on the electrical characteristics of both strained Si and conventional SOI n-MOSFETs was investigated. The authors demonstrated that post-RTA heat treatment rather than typical RTA is inevitable to obtain enhanced DC characteristics in strained Si n-MOSFET. This is attributed to the suppression of channel surface roughness owing to post-RTA

Real-time measurements of GexSi1 – x/Si(001) composition and segregation dynamics in Sn/Si(001) in molecular beam epitaxy are demonstrated using parallel detection reflection electron energy loss spectroscopy. Parallel detection enables quantitative acquisition of low-loss spectra in a time of < 500 µs and surface composition determination in GexSi1 – x/Si(001) via Ge L2,3 core loss analysis to a precision of approximately 2% in time of order 1 s. Segregation and trapping kinetics of monolayer thickness Sn films during Si epitaxy on Sn-covered Si(100) has also been studied using the Sn M4.5 core loss.

We fabricated narrow fins structures and non-planar MOSFETs like FinFETs and triple-gate MOSFETs using plasma doping with substrate heating under 350··, and measured their I-V characteristics. Fins and MOSFETs using low-temperature doping process show good current drivability and low subthreshold slope. However, without post high-temperature thermal annealing, this process could not avoid generating defects and traps as well as mobile protons on the gate and gate oxide interface and junctions, and therefore degraded device reliability. The results of ultra-small MOSFET research show possibility of new memory devices with these traps and ions in devices.

This paper explores the effect of silicon-on-insulator (SOI) thickness scaling on its electrical properties. It is observed, for the first time, that the sheet resistance of ultra-thin SOI is lower than that of thick SOI under the same conditions of plasma doping and thermal annealing at low RTA temperature. This shows that dopant profile distribution and activation efficiency are different with different SOI thickness and different RTA temperature. In this work, we investigated the sheet resistance of SOI and made a comparative study of change in drain saturation current of a long channel FD SOI-MOSFET, fabricated with various SOI thickness and RTA temperatures, for the understanding of thermal scaling of ultra-thin SOI.

A novel plasma doping technique for fabricating a nano-scale silicon-on-insulator (SOI) MOSFETs have been investigated. The S/D extensions of the tri-gate structure. SOI n-MOSFETs were formed by using elevated temperature plasma doping method. The activation annealing after plasma doping was excluded to minimize the diffusion of dopants, which resulted in laterally abrupt S/D junction. We obtained low damage shallow junctions and sheet resistance of 920 /spl Omega/ //spl square/ by the elevated temperature plasma doping of 527/spl deg/C. A tri-gate structure SOT n-MOSFET with a gate length of Sub-50 nm was successfully fabricated and revealed suppressed short channel effects.