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This paper demonstrated the application of several dielectric materials with different dielectric constant (k) (i.e. silicon dioxide (SiO 2 ), aluminium oxide (Al 2 O 3 ), and hafnium oxide (Hf02) with $k$ values of 3.9, 9.0, and 25.0, respectively) on the silicon nanowire (SiNW) surface in order to study their effect on the performance of SiNW field-effect transistor (SiNW-FET) biosensor through simulation tool. The biosensor structure was designed and simulated in Silvaco ATLAS. Different interface charge (Q F ) values representing actual target biomolecules were applied onto different high-k dielectric materials surface covering the SiNW channel between drain and source as transducer for biomolecule interaction. With increase of $k$ values exhibited by different high-k dielectric materials, the output drain currents (I D ) of the biosensor were increased during detection of interface charges, which were applied on the surface of dielectric layers. Therefore, the biosensor's performance toward detection of interface charges was improved especially when Hf02 was used as dielectric layer for the biosensor with device sensitivity and limit of detection (LOD) of 17.32 µA/e·cm2 and 1.82×1010 electronic charge/cm−2, respectively.

C-reactive protein (C-RP), a biomarker for inflammatory validation associated with cardiovascular disease (CVD). Major infection or severe trauma trigger the activation of this protein in the patient's blood. In this paper, the conventional field-effect transistor (FET) is fabricated and followed by direct deposition method of molybdenum disulfide (M O S 2 ) nanosheets. The deposition of MoS 2 nanosheets with the conjugation of 30 nm gold nanoparticles on the 100 µm active channel shows the good response of electrical signals for C-RP detection. Analysis of the MoS 2 and AuNPs was well-supported by atomic force microscopy, scanning electron microscopy, UV-Vis spectroscopy, and high-power microscopy. Finally, the detection limit of 100 fg/mL was attained.

Cardiovascular biomarker appears in blood when the heart experiences extreme anxiety joining deficient of oxygen in the blood. Cardiac Troponin I (cTnI) is one of those biomarkers also known as a highest quality level of biomarker to detect acute myocardial infarction (AMI). In this paper, an aluminium interdigitated electrode is fabricated by using conventional fabrication process followed by deposition of ZnO nanoparticles on top of the device using the sol-gel method. The device deposited with nanoparticles transduce the biological response of the cardiac troponin into electrical signals. The device characterized under Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) to observe the surface morphology. Finally, the device demonstrated for detection of cTnl protein at different concentration (from Ing/mL to 10µg/mL). The result shows that sensor able to detect the cTnl atµg/mL concentrations level of the protein.

A biosensing platform for detection of the prostate cancer's ‘gold standard’ marker, the prostate-specific antigen (PSA) is reported. The developed assay combines the application of gold interdigitated microelectrode as the sensing device, together with the electrochemical impedance spectroscopy (EIS) in Faradaic mode of detection for a highly sensitive quantification of PSA binding on the sensor's surface. The binding test revealed the developed assay's capability in detecting the target in sub-pico range of concentration of 10 ng/ml down to 100 pg/ml of PSA in 100 mM phosphate buffered saline (PBS) solution (pH 7.4), covering the clinically accepted PSA threshold value for the ‘screening’ of prostate cancer at 4 ng/ml of PSA.

The paper presents a top-down method of fabricating polycrystalline silicon (poly-Si) nanowire using the conventional photolithography technique and the deposition of gold (Au) thin film as the contact pad via a thermal evaporator. Photolithography, also called as optical lithography or UV lithography were used to pattern nanowire on the substrate. poly-Si has a dimension of 1 µm after the conventional photolithography process. In furtherance of achieving a nanowire, the photoresist was then developed using a resist developer at several time steps (trimming process) for miniaturization during the development process. Subsequently, Au on a nickel (Ni) electrodes were patterned on both side of the fabricated poly-Si nanowire by lift-off process that comprise of conventional photolithography for pattern transfer and metal deposition via thermal evaporator. In this research, the width of the nanowire that has been obtained was 852.24 nm with height of 33.42 nm. Whilst, for the electrical part it is noticeable that there was an increase in current value when the nanowire been tested in bare condition, with deionized water (DIW), pH 7 and finally with pH 4. The characterization of the poly-Si nanowire dimension was observed using an optical microscopy and electrically characterized by measuring the two-terminal current-voltage (I-V) characteristics.

In this paper, a study on the deposition formation of reduced graphene oxide (rGO) via drop casting onto glass substrates were carried out. Two different solvents (deionised water (DIW) and N-Methyl-2-Pyrrolidone (NMP)) and cleaning reagents (RCA-Standard Clean-1 (RCA-1) and isopropyl alcohol (IPA)) were used for the investigation. The deposition structures were analysed by using high-power and scanning electron microscopes. Ultraviolet-visible (UV-Vis) spectroscopy was used to validate the authenticity of the as-prepared rGO. Results indicated that the as-prepared rGO from DIW was more suitable to be deposited on the glass substrate cleaned with IPA compared to RCA-1, yielding better uniformity and a high density of rGO coverage. Meanwhile, the rGO suspension prepared from NMP and cleaned with RCA-1 was more suitable to be deposited on the glass substrate. The combination of solvents and cleaning reagents affected the glass substrates surfaces where a different in deposition structured were observed. Furthermore, a concentration of 1 mg/mL was considered as a very high concentration to prepare the rGO colloidal suspension where such a concentration results in a poor exfoliation.

This paper describes the Shallow Trench Isolation (STI) stress effect on 45 degree rotated MOSFET layouts. 45 degree rotated PMOS layout with large Sa (active space) shows 15% increase in saturation drain current (I dsat) as compared to the non-rotated ones. On the other hand, PMOS layout with minimum Sa and same rotation show 3.8% I dsat enhancement only. This is because when rotated 45 degree, the channel orientation changes from to axis. This enhances the PMOS I dsat with large Sa. At minimum Sa, the I dsat enhancement is small because the PMOS is at high STI stress. For or non-rotated layouts, the STI stress is observed to increase the I dsat by 14 %. The impact of STI stress effect on PMOS with minimum Sa is negligible at or rotated. For NMOS, no Idsat enhancement or degradation is observed on 45 degree rotated layouts. Finally, we have studied the effect of using 45 degree rotated PMOS in ring oscillator circuit.

This paper are focused to characterize the difference CNTs deposit on Titanium Oxide (TiO 2 ) as metal sensing for formaldehyde molecule detection. The sensor was fabricated by using two types of CNTs which is Single wall carbon nanotube (SWCNT) and Multi wall carbon nanotube (MWCNT) for measuring the most suitable device for detecting the formaldehyde gas. Characterization of difference IDE pattern is demonstrated by various measurements.

Interdigitated Electrode are known as one of the hallmark of biosensors because of its numerous applications. Biosensors projects to be preferable devices especially in hospitals and other medical faculties as well as in other interdisciplinary fields because of its small size and high sensitivity. Since size plays a salient role in sensitivity and selectivity, in this research, 140 nm IDEs and 50μm IDEs were used to test the electrical characterization using current-voltage (I-V) for comparison. The morphological of IDEs were taken by using High Power Microscope with 50x magnification and Scanning Electron Microscope (SEM). Aim of this research is to test electrical characterization on bare aluminium IDEs and IDEs doped with pH solution for both nano Interdigitated Electrode (nIDEs) and also micro Interdigitated Electrodes (μIDEs). Each IDE was tested to achieve a stable pattern of electrical measurements and results were obtained by current-voltage graph. The pH solutions used for this research from pH 2 to pH 12 were dropped on nano IDEs as well as micro IDEs and conductivity was tested using two-point probe and based on the results it was proven that the conductivity of both types of IDEs differs depending on their finger gap size.

Efficient micromixing is required for fast reaction and improved mixing performance for DNA extraction in microfluidic devices. This study outlines a simple, low cost approach for prototyping design and fabrication of PDMS microfluidics micromixers for DNA extraction. The design is plotted using AutoCAD software and the master template is fabricated using a negative photoresist, SU-8, on a microscopic glass slide. PDMS was used for replication of microfluidics channels to create a microfluidics chip due to its biocompatibility as well as other advantages pertaining to high performance of fluid delivery and biochemical reactions. High power microscopy (HPM) results show successful, insignificant difference in size

This paper was studies about the effect of difference fabrication of TiO 2 nanoparticle sensor on surface morphological structure and electrical properties for detection of formaldehyde. Two type of deposition method are used to deposit TiO 2 nanoparticle layer on IDE/Si/SiO 2 substrate. The fabrication of IDE was done by using conventional photolithography process. In the second method, the solution TiO 2 was directly deposited by using e-beam evaporator. The fabricated of sensor was further validated through characterization on morphological surface inspection and electrical properties of the device. The roughness of TiO 2 film was demonstrated that the latter method is preferable due surface uniformity approximately 70 nm in grain size to provide resistance barrier to allow current flow when interface with the formaldehyde. The result was demonstrated by various measurement.

Among many methods to synthesize Zinc Oxide (ZnO) thin films, the most commonly used method is sol gel technique. In this study, we have used sol gel approach deposited on silicon substrate. To investigate the structural and electrical properties of ZnO thin films, silicon substrates were coated at 1, 3, 5 and 7 layers of ZnO thin film. For characterization purposes, SEM and Current-Voltage measurements were observed and recorded to optimize the morphological and electrical aspects of the ZnO respectively. From the results recorded, it is justified that the more grain particles present on the substrate the higher the current conducted. However, an excessive amount of grain particles can cause crowding effect and thus, alter the electrical and surface characteristics of the sample.

Soft lithography describes the moulding of polymers using master templates, a technology that is widely used in microfluidics fabrication. This study outlines a quick and low cost soft lithography processing using negative photoresist (PR) SU-8 on glass substrate to create a master template for subsequent Polydimethylsiloxane (PDMS) replication in overall microfluidics fabrication. Two types of negative PR, SU-8 5 and SU-8 2015 are used in this study to increase the adhesion of the resist. Inkjet transparent mask is used as microfluidic photomask instead of expensive chrome mask and the design was made on AutoCAD software. Results from high power microscopy (HPM) and 3D profilometer show successful fabrication with

Graphene is one of the carbon allotropes that possesses several outstanding properties which is suitable to be used in bio-sensing applications. Reduction of graphene oxide (GO) is the main concern of researchers in preparing better quality of graphene at a lower cost with mass production as the reduced GO partially restores the pristine graphene. The reduced graphene oxide (rGO) is then mixed with multi-walled carbon nanotubes (MWCNTs) to form the three-dimensional arrangement of rGO-CNTs hybrid nanocomposite which can overcome the limitations faced while using rGO or MWCNTs separately in bio-sensing applications. Here we demonstrate the sample preparation of rGO-CNTs hybrid film for biosensing applications. GO was prepared by modified Hummer's method and rGO was obtained by reducing GO with L-ascorbic acid. The characterizations of rGO-CNTs hybrid film were examined via Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Fourier Transform Infrared Spectroscopy (FTIR). The surface morphologies of GO, MWCNTs, GO-CNTs hybrid and rGO-CNTs hybrid films were observed via SEM. The thickness and the surface roughness of MWCNTs, GO, GO-CNTs hybrid and rGO-CNTs hybrid films were examined via AFM. FTIR was carried out to examine the carboxyl functional group in the rGO-CNTs hybrid film.

In this paper, the modeling and simulation of a layered surface acoustic wave device based on ZnO/128° YX LiNbO 3 were conducted using Finite Element Method (FEM) in COMSOL Multiphysics 4.3b platform. The SAWs propagation characteristics were numerically investigated with variation in the ZnO layer thickness. The results show that the SAW device frequency response was varied with the ZnO layer thickness from 166.1 MHz to 150.4 MHz. The free and metalized phase velocities (ν f and ν m ) were calculated and used to calculate the electromechanical coupling coefficient (K2) of the structure. The results show that a large coupling coefficient of 6.05% can be obtained in 500 nm ZnO layer thickness which is in a good agreement with the data published by Nakamura and Hanamoka.

Characterization on a planar nano-device, known as self-switching diode (SSD) aimed for rectification application at high frequencies is reported. Simulation has been conducted on InGaAs-based SSD with 70 nm L-shaped channels using twodimensional (2D) ATLAS simulator. The current-voltage (I-V) characteristic of the device is found asymmetrical, similar to I-V behavior of a diode. The structure geometries of the channel are varied in term of channel length, channel width, and trenches width to observe the I-V behavior of the device. Furthermore, the curvature co-efficient of the SSD has been evaluated by extrapolating the simulated I-V graphs and the rectification performance of each configuration has been observed and concluded. The results obtained can assist the optimization in the design of the SSD to efficiently operate as microwave rectifier, especially in radio frequency harvesting application.

interdigitated electrodes (IDEs) with GO-MWCNTs thin film as sensing membrane have been successfully developed on silicon substrate for DNA detection. The physical surface morphology of GO-MWCNTs were characterized using field emission scanning electron microscopy (FESEM) and the surface structural was determined by X-ray powder diffraction (XRD). The chemical bonding of GO-MWCNTs were examined by using Fourier transform infrared spectroscopy (FTIR). FTIR spectrum successfully shows that the GO-MWCNT hybrid thin film contained carboxyl functional groups by showing peaks at 3375cm −1 and 1690cm −1 for (O-H stretch), and (C=O stretch) respectively. The IDE biosensor was measured on DNA immobilization activities. The current of the IDE after the immobilization at 2V was drop from 0.9mA to 0.75mA. The difference of the current signal is due to the negatively charged backbones of the DNA probes repelled electrons from accumulating at the conducting channel. The IDE current was further decreased when the DNA hybridization took place.

This work investigates the impact of gate-source/drain underlap (L UL ) together with different ground plane (GP) structures on the digital figure-of-merit (FoM) of 25 nm UTBB FDSOI devices using two-dimensional (2D) numerical simulations. It is found for all ground plane structure, longer underlap produces 1) lower off-current (I off ) but at a cost of lower on-current (I on ), thus a lower transconductance (g m ). In terms of the impact of different GP structures, longer underlap shows 1) stronger influence on the I d –V g characteristics 2) an improvement in the DIBL as a result of lower effect of drain potential, compared with no-underlap. In addition, DIBL dependence on various GP structures is higher at shorter underlap as compared to longer underlap. It is shown that to achieve good Short-Channel Effects (SCEs) control and optimal digital results, careful design consideration need to be done in selecting a combination of L UL and GP structures to be adopted in the device design, as there is a trade-off between I off and I on , as well as on the DIBL.

In this paper, the device performance in ultrascaled junctionless (JLT) over junction transistor (JT) are investigated using numerical TCAD Atlas 3D simulator software on 10 nm gate length. The main parameters of interest are analogue and radio frequency figure-of-merits. Result shows no significant advantage of JLT for analog and RF applications as compared to normal junction MOSFETs transistor. Slightly higher gate-to-gate capacitance in JLT architectures related to high doping in the channel, which is not beneficial for RF applications.

The paper reports on numerical simulation of underlap field effect transistor (FET) device architecture on silicon-on-insulator (SOI) for a robustness used in biosensors application. By using the Silvaco ATLAS device simulator, the simulation is aimed at elucidating the effect of length of underlap, location of underlap, device etching profiles, and effect of back-gate biasing on the magnitude of drain current (I D ). It is shown that the longer underlap and an etched silicon profile introduced higher parasitic resistance, thus decreasing the I D response. The I D response is higher for device with underlap between the gate-drain terminals as compared to gate-source terminals. Positive back-gate bias increases and shifts the current, and reduced the threshold voltage required to turn on the device.

An electrode has been fabricated for detection of HIV-1 Tat protein. Functionalized carboxylated multiwalled carbon nanotube (COOH-MWCNT) has been deposited by spray technique on the electrode to act as amplification layer and immobilization site for aptamer. Aptamer has been proved that it is highly specific for the detection of its target molecule. In this paper, we demonstrated the immobilization of split aptamer on MWCNT-modified electrode by interaction of carboxyl functional group from MWCNT and amine functional group from aptamer. The implementation of split RNA aptamer as a recognition element is promising for detecting HIV-1 Tat peptide. Detection has been conducted in control sample and HIV-1 Tat protein sample. The intercalation of aptamer and protein has given changes to the electrical signal and quantified by picoammeter showing decrease in current value of 3.74nA compared to control which different only 1.64nA.

This paper presents the fabrication and characterization of metal oxides based sensor for detection of formaldehyde gas. Three different metal oxides are considered (i.e. TiO 2 , ZnO and SnO 2 ) as transducer for the optimum sensitivity and selectivity detection. The metal oxides are deposited on the top on aluminum/glass substrate using sol-gel technique. Comparison performance has been made and found that SnO 2 gives better sensitivity detection of formaldehyde molecule as compared with TiO 2 and ZnO. At this stage, the test validation is done by dipping the electrode in 100 ppm formaldehyde liquid solution. Further, we show that SnO 2 provides better selectivity toward the detection of formaldehyde and compared to acetone, ethanol, formaldehyde, isopropanol and methanol. Lastly, we demonstrate that, our sensor capable to detect down to 0.010 ppm of formaldehyde liquid. This excellent capability is achieved due to good uniformity and high surface-to-volume (approximately 70 nm) of SnO 2 surface morphology characterized by using AFM.

Colorimetric analysis has been used to determine the biomolecules interaction in a solution with that can be indicated from color changes that can be observed either by spectrophotometer or naked eyes. Gold nanoparticles (GNP) which originally exist as pink color solution will aggregate and turn to purple color when mixed with salt solution. It was used as the basic solution and it mixed with aptamer probe and when NaCl salt solution was added to the mixture, the color changes was observed from pink to purple in the presence of HIV-1 Tat protein target. GNP are capable of adsorbing small oligonucleotides due to their propensity for electrostatic attractions, hydrophobic absorption, and covalent binding. In this experiment, GNP adsorbed the aptamer probe covering its surface preventing salt solution from interacting with GNP. Colorimetric detection is use to prove the interaction that happened in the mixing solution of aptamer and protein by observing the color changes with the presence of target and measuring the absorbance of wavelength of the solution. The wavelength shift has been observed due to changes in color. The value of wavelength for GNP observed was 522nm and shifted in wavelength can be observed in the presence of tat protein at 531.83nm while for tat peptide at 529.84nm

This paper presents the electrical properties of ZnO deposited on Al interdigitated electrodes (IDE) for detection of synthetic formaldehyde liquid at different concentration. Firstly, the 50-nm gap size of Al IDE pattern was designed and fabricated. The ZnO solution was prepared and deposited on entire surface consisting of Al IDE and SiO 2 (in between the IDE fingers) structure through sol-gel method. The surface was characterized by using scanning electron microscopy (SEM) and the electrical characteristics was measured by using source meter (keithley 6487). Result shows that the IDE with ZnO device sensor is capable to detect various formaldehyde liquid concentration (5 ppm, 3 ppm and 1.5 ppm).

As a present work, a capacitive electrochemical biosensor i.e. Interdigitated Elecrode (IDE) was successfully designed and fabricated with aluminium as its contact pad deposited on a semi-conductor (silicon) surface using a thermal evaporator. For the fabrication method, lift-off photolithography process is applied followed by morphological and electrical characterizations. Meanwhile, the design of the IDE mask was done by the aid of AutoCAD software with miniaturization for future work of Ganoderma boninense detection. The electrical performance of the microelectrode sensor proved to be remarkable and for further studies, surface modification need to be done for sensing of biomolecules especially the target DNA Ganoderma. This study has proven that with the simple process of photolithography, IDEs can be fabricated within few hours and with low cost.

A planar nanodevice, known as the self-switching diode (SSD) has been demonstrated to rectify electromagnetic signals at microwave and terahertz frequencies. This diode has a non-linear current-voltage (I-V) characteristic due to the structure of the device which consists of asymmetric nanochannel. To further explore the properties of SSD rectifiers, in this work, silicon-based SSDs with different dielectric materials that filled up the trenches of the devices were simulated using ATLAS device simulator under the temperature range of 250 K–500 K. The results showed that the rectification performance of the SSDs was deteriorated with increasing temperature for all dielectric materials which might be due to the thermal-activated electronic transport behavior of the devices.

Characterization on an InGaAs-based self-switching diode (SSD) aimed for rectification application at high frequencies is reported. Simulation on the current-voltage (I-V) characteristic of L-shaped 70 nm channel SSD has been conducted using ATLAS two-dimensional (2D) simulator for different insulating channel materials with relative permittivity ranging from 1.0 to 9.3 under temperature range of 300 K–600 K. A similar I-V curve to diode behavior has been observed. Furthermore, the curvature co-efficient of the SSD has been evaluated by extrapolating the simulated I-V graphs and the effects of both permittivity and temperature to the rectification properties are observed. The results obtained can assist the design of SSD to efficiently operate as microwave rectifier, especially in radio frequency harvesting application.

A planar nanodevice, known as the self-switching diode (SSD), has a nonlinear current-voltage (I-V) characteristic which can be exploited as a high-speed rectifier in a wide range of applications. This diode-like I-V behaviour is achieved due to the structure of the device which consists of an asymmetric nanochannel. In this work, the rectification properties of silicon-based SSDs with different geometry of the nanochannel were reported. The characterization have been performed by means of ATLAS device simulator. The results obtained can be used to facilitate in improving the rectifying performance of the device.

This paper reports on the development of a piezoresistive microcantilever sensor read-out circuitry to detect acceleration, biological or chemical activities. Laser micromachining technique is used in fabricating the piezoresistive microcantilever sensor as well as assisting in the cantilever beam and piezoresistor shape formation. In order to test the sensor performance, a Wheatstone bridge which acts as resistive sensor is integrated with three other resistors and the fabricated sensor. A set of amplifier circuit consisting of INA128 is developed to amplify and extract the electrical signal component of the bridge circuit. The resistance and output voltage characteristic of the Wheatstone bridge is investigated, where the percentages difference between the calculated and measured output voltage is very low and similar to each other. The sensor response to vibration is also studied using an electro-dynamic vibration system. The system is designed specifically to enable the accessibility of a small resistivity change due to outside reaction.

In this paper, the effect of silicon body thickness (TSi) and silicon body width (WSi) variation on DC characteristics in 100 nm gate length silicon-on-insulator (SOI) junctionless (JL) and junction transistors has been investigated by using numerical simulations. The digital figure-of-merits characteristics such as threshold voltage (VTH), on-current, subthreshold voltage, and drain-induced-barrier-lowering are the main parameters that have been investigated. Based on the simulations, the JT device is less sensitive to variation of TSi and WSi compared to JLT.

This paper presents real time detection of formaldehyde gas by using the properties of tin dioxide (SnO2) thin film on a formaldehyde gas sensor. SnO2 thin film is coated on aluminum IDE electrodes which is fabricated on a glass substrate by using sol-gel technique and annealed to get the crystallization of SnO2. The surface morphologies of the SnO2 thin film is examined and studied through atomic force microscopy (AFM). For the real-time detection, formaldehyde gas was inject inside the gas chamber. The hot plate with the temperature of 200 °C inside the gas chamber is used to evaporate the formaldehyde gas, subsequently exposing it to the surface of SnO2 thin film. Electrical conductivity of the SnO2 thin film is increased and allowed current to flow through it. The potential difference at the gas sensor is measured using voltmeter. During real time detection, various amount of formaldehyde liquid which are 0.1 μl, 0.3 μl, and 0.5 μl are injected into the gas chamber, thus produced potential differences of 0.8 V, 2.2 V and 3.5 V, respectively.

This paper presents the preparation and characterization of zinc oxide (ZnO) thin film prior deposition on the channel of field-effect transistor with back gate biasing (FET-BG) for biosensing application. Sol-Gel technique is a chosen method for the preparation of the ZnO seed solution, followed by the deposition process through spin coating technique on the silicon dioxide (SiO2). Prior to that, the SiO2 layer is grown on a silicon die. The ZnO seed solution is deposited at various numbers of coating layer (1, 3, and 5 coating layers), baked, and annealed prior to characterization of its surface morphological, structural, crystalline phase, and electrical characterization. The results obtained give a significant evidences for the future deposition process of the ZnO thin films as the FET-BG biosensor device on the silicon-on-insulator (SOI) wafer.

In this paper, we present the fabrication and electrical characterization of field-effect transistor-based sensor with integrated graphene oxide (GO) on channel between source and drain. We aim to demonstrate the optimum condition in electrical performance for field-effect transistor-based biosensor device. Graphene oxide prepared by using modified hummers method was deposited on the channel with different amount to act as amplification layer on the FET. The structural properties of GO were examined using photoluminensence (PL). A 3D surface profilometer were used to observe the surface morphology of GO-FET. Multi-graphene layer on the FET channel result in increasing the current flow in the device and make it more sensitive to be used as biosensor.

In this paper, the effect of gate workfunction variation on electron concentration at depletion and inversion as a function of applied gate voltage for 100 nm gate length silicon-on-insulator (SOI) junctionless (JLT) and junction (JT) transistors are investigated. It shows that the JLT device is properly function and achieving full-depletion without losing gate controllability at higher gate workfunction of more than 5.0 eV whereas the designated JT device is more wider range, ranging from low, mid-gap or high workfunction.

Nanocrystalline TiO2 anatase thin films have been prepared from alkoxide solution via sol-gel method. The effects of two protic solvents of methanol and ethanol of TiO2 thin films were systematically investigated under room temperature. The films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet spectroscopy (UV-vis), current-voltage (I-V) and capacitance-frequency (C-F) test. The structure growth, morphological, optical and electrical characteristic of the TiO2 thin films were influenced by different factors such as dielectric constant, film thickness, and particle size. XRD confirmed the presence of tetragonal anatase phase in all samples after annealed at 400°C. Furthermore, it was inferred from UV-visible transmittance spectra that although band-gap energy of the films are independent of solvent type, the particle size, film thickness, crystallinity and electrical measurement (I-V and C-F test) of the films are highly affected by the type of solvents.

Biosensors become a main attraction nowadays due to its importance towards human health. Its allow rapid and label-free detection that provides low cost clinical sampling. A FET device was fabricated from silicon-on-insulator (SOI) type of wafer with titanium dioxide (TiO2) thin film as a sensing medium. TiO2 was deposited by using sol-gel solution, spin coated on the device, patterned and anneal. The physical characterization by using AFM and XRD was conducted to confirm the thin film was a TiO2 and electrical characterization was to determine the electrical properties, stability and sensitivity of the devices. From the result AFM and XRD confirm the thin layer was a TiO2 layer with grain boundaries and several peaks of TiO2 anatase crystal structure. The current-voltage (I-V and Vbg-Id) show that the TiO2 thin film has a good electrical properties and sensitivity that very suitable in sensing application especially detecting biomolecules for disease detection.

In this work, we investigate the impact of using different gate dielectric materials i.e HfO2 and Si3N4 as compared to the conventional SiO2 with equivalent oxide thickness (EOT) of 1.2 nm on the digital and analog performance of UTBB SOI MOSFETs of 10 nm gate length with different ground plane (GP) structures under the double-gate (DG) operation-mode by numerical simulations. It is found that Si3N4 provides good digital and analog performance in terms of lower DIBL and higher voltage gain, Av. Meanwhile, GP-A structure which employed p+ doping under the source and drain regions beneath the BOX is able to provide not only high Av but also a stable gain throughout the frequency range as compared to other GP structures. Thus, the configuration of GP-A structure with Si3N4 as the high-k materials is proposed for the design of analog and RF circuits.

Surface Acoustic Wave (SAW) device uses piezoelectric effect to generate acoustic wave on the piezoelectric substrate by using Interdigital Transducers (IDT). Early application was in telecommunication field as filter and resonators. However, due its sensitivity to mass, viscosity and velocity changes on the path between two IDTs, it is used as biosensors. In this project, the focus will be on fabrication and characterization of the IDTs parameter of the SAW device using conventional photolithography and lift-off technique. Finger width, acoustic aperture and number of IDT finger pairs were varied to analyze its effect on the resistance, coupling capacitance, and frequency response. After the lift-off technique, the completed SAW devices were characterized with respect to its parameter for its current-voltage, capacitance-voltage and frequency response. SAW device with more IDT fingers, higher finger width and acoustic aperture produce lower lead resistance and higher capacitance.

Titanium dioxide (TiO2) is one of a metal oxide material group that shows a promising future in biosensors application. TiO2 possess both physical and chemical resistant that can extend a device lifespan. However, etching of TiO2 with very high selectivity is a challenging process in achieving good and desired profile particularly in nanometer scale. In this work, we present the anisotropic etch profile. Three types of ICP-RIE recipes are used i.e. CF4/O2, Ar/SF6 and CF4/Ar. Prior to that, the TiO2 sol-gel is deposited on top of SiO2 layer. All the results are optically and physically characterized by using 3D-surface profilometer and atomic force microscopy (AFM) and finally followed by electrical characterization.

Silicon carbide (SiC) is an important ceramic for engineering and industrial applications in harsh conditions of high temperature oxidative environment. For the synthesis of SiC in manufacturing process, conventional heating process is commonly used. In this study, SiC nanowhiskers are synthesized by microwave heating from mixture of graphite and silica. Graphite and silica in the ratio of 3:1 were mixed in ultrasonic bath using ethanol as medium for one hour. The mixture was then dried on hotplate and cold pressed uniaxially into a pellet die. The pellet was then heated by using laboratory microwaves oven to 1400°C at heating rate of 20 °C /min and temperature was kept for 30 minutes. Scanning electron microscopy (SEM) showed that SiC nanowhiskers were successfully synthesized. X-ray diffraction (XRD) pattern indicated SiC phase was present after the mixture of graphite and silicon dioxide (SiO2) were exposed to microwave irradiation. Electron microscopy analysis showed that the SiC formed was in the form of nanowhiskers.

The biosensor platform of graphene material has grown rapidly in the past few years due to their unique properties in electrical, thermal conductivity, large surface area, high fracture strength, high young modulus and biocompatibility. In this work, the chemically modified graphene oxide solutions were studied for electrical performance toward biosensor applications. The graphene oxide solutions were sprayed manually on top of silicon substrate at various temperatures of 100, 200 and 300 °C, respectively. Out of those temperatures, at 100 °C, the surface morphology of reduction graphene oxide showed a better performance in electrical measurement. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy were carried out to investigate the thermal reduction and the formation of graphene through surface morphology observation. Then a surface modification will conducted using APTES and electrical characteristic of the current-voltage (i-v) were performed.

The surface properties of nanodiamonds play a decisive role in many nanodiamond applications, particularly in biological and medical applications. The surface functional groups largely determine the interactions between nanodiamonds and biomolecules. In this study, a sonication treatment of nanodiamond powder was investigated upon depositing onto silicon substrate via a spray method. The surface morphology of nanodiamond deposited on silicon was observed using a Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM), respectively. Fourier Transform Infrared Spectroscopy (FTIR) was used in order to determine the difference between unmodified nanodiamond and modified nanodiamonds with APTES upon aptamer immobilization. The aptamer modified nanodiamond can be used for development of nano electronic device for detection of biomolecules.

In this work, we investigate the impact of varying silicon-body thickness, Tsi i.e 5 nm, 7 nm, 10 nm and 12 nm on the digital figures-of-merit performance of Ultra-Thin Body and Buried Oxide (UTBB) SOI MOSFETs of 10 nm gate length with different ground plane (GP) structures under the double-gate (DG) operation-mode. We show that degradations of the digital characteristics i.e DIBL, subthreshold-slope (SS) and Ioff occur with an increased in Tsi. Meanwhile, no significant improvement in Ion is observed with the reduction in Tsi whereas thicker Tsi produces a slightly higher transconductance, gm. In terms of the impact of different GP structures, significant variations in DIBL and SS is observed with thicker Tsi as different GP structure is employed, and these variations are gradually suppressed when Tsi is decreased. In other words, advantages of different GP structures are not significantly apparent at thinner Tsi.

Growth of titanium dioxide (TiO2) nanowires was studied on the seed layer of TiO2 through hydrothermal growth method. Here, the growth of nanowires TiO2 on Si (100) substrates by using the two steps method. Different seed layers of TiO2 were prepared by using sol-gel method, deposited by spin coating and annealing, followed by the growth of TiO2 nanowires by using the hydrothermal method. Acetic acid was used as a stabilizer to synthesize a TiO2 seed layer. The aim of this study was to understand the role of polycrystalline size on thin film towards the diameter of nanowires grown as a sensing area in Surface Acoustic Wave (SAW) Biosensor. The morphology and microstructure of the thin film seed layer and TiO2 nanowires were characterized using X-Ray diffraction (XRD), scanning electron microscope (SEM), field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM).

The combination of nano/micro technology, biology and metal oxides materials have seen great advances in the development of transducers and biochips for biological and medical fields. In this work, TiO2 nanoparticles thin films were prepared using sol-gel method and annealed at 400°C to promote nanoparticles crystallization in anatase phase. The influence of surface topologies and uniformity distribution of TiO2 thin films were investigated using AFM, whereby the surface structural was determined by XRD. The conventional photo-lithography technique was applied in the fabrication of micro-gap interdigitated electrodes (IDEs) with 7 μm gap size between the adjacent fingers. This device will be employed as an electrochemical sensor to detect the bio-molecules thru electrical characteristics. The fabricated micro-gap Au/Ti IDEs gap size was further inspected using the scanning electron microscopy (SEM). Purchased pH buffer solutions which varied from pH4 to pH 12 is dropped on the micro-gap IDEs and the effect on it is investigated for the application in pH measurement.

Field effect transistor (FET) with graphene oxide deposited on the channel for biosensor application is fabricated using p-type silicon on insulator (SOI) wafer. The graphene oxide (GO) is deposited by using an effective and low cost technique called spray pyrolysis mechanism on the silicon dioxide layer (i.e. after the silicon with 70 nm is etched). The physical surface topology is characterized using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Results show that the GO flake exist on the deposited area with thickness ranging from 3 nm to 8 nm. For electrical characterization, the device uses a back-gate to modulate the channel. Results show that the GO show better conductivity, stable response and less noise proving that it is suitable for biosensing applications.

The study of MWCNT layer deposition has been conducted by using spray method to investigate the effect of different height and volume towards the surface morphology of the layer formed. Different volume of MWCNT solution which are 0.2 ml, 0.4 ml and 0.8 ml have been sprayed on glass substrate and the intensity of the MWCNT increased concurrent with the rise of the solution volume as observed under SEM. The thickness of the layer has been measured by using Stylus profiler display an increasing thickness pattern with increase in solution volume while with increase in height of the spray towards the substrate, the MWCNT layer formed decreased distantly. The MWCNT layer sprayed with volume of 0.8 ml and height at 10 cm shows efficient tube connection and can be further used in electrical device measurement.

This paper presents the development of gas chamber for testing and characterization of gases with different concentrations. By using glass as the chamber material, it able to provide strong and air-tight structure and prevent odor chemical gases from leaking which can effect the environment. The glass chamber also enables easy monitoring (from the external) of the hardware connections, to ensure that they are always intact and in good condition. The measurement plate in the chamber consists of a copper probe, sensor, heater and conductor. A temperature within the range of 200 °C to 300 °C is required to activate the sensing mechanism. Initial testing shows that the chamber provides well enclose environment for gases detection.

As technology advanced from bulky to the tremendous miniature feature size devices, the patterning process changes according to the technology in order to improving the quality of producing a tiny device. However, in research experiment, costing and ease of use is well preferred rather than high throughput outputs. Hence, such low cost photolithography technique which is a crucial part in fabrication process begins from mask design is introduced. A common mask printing on transparency film via inject printers comes in handy for low cost fabrication together with time saving and easy to generate. The only drawback is that printing dimension must not less than 100μm and definitely the bigger the size, the better the resolution of the transparency mask. On the other hand, the less devices that able to fit in a wafer. Design of this mask drawn using AutoCAD drawing tools using multiple trimmed circles that combined with a pair of contact pad. Tangible printed mask enable the next steps of photolithography to be proceed and patterns occurs upon completion.

The capability to grow the manufacturing grade ultra-thin dielectrics hold the key to the continuous miniaturization of semiconductor devices. While the thermally grown SiO 2 has been used as a gate dielectric ever since the decades of silicon device began, it appears that the electrical and physical properties of pure SiO 2 are not good enough to provide acceptable performance for ultra-thin gate dielectric film. There are many available methods to control the growth of the ultra-thin film. In this paper, we control the growth rate of dry thermal oxidation by incorporating nitrogen gas during the process. The Deal Grove model is universally accepted as the physical model to describe the thermal oxidation process. However, at the initial oxidation stage, this model cannot predict the process satisfactorily. The incorporated nitrogen will neutralize the growth sites at the oxide-silicon interface, which significantly slows down the oxidation process when N 2 gas is used as an oxidizing ambient. It would also affect the linear rate constant for the Deal Grove equation where, linear rate (B/A) is the reaction at the Si/SiO 2 regent that depend on the oxygen and nitrogen gases. The result was compared with the calculated growth rate, which based on the Deal-Grove model to investigate their correlation. Where for the result, it shows that the linear rate constant (B/A) of deal grove model for the dry oxidation of thickness