In this work, the metal-oxide-metal (MOM) capacitor in the scaled CMOS process has been modeled at high frequencies using an EM simulator, and its layout has been optimized. The modeled parasitic resistance consists of four components, and the modeled parasitic inductance consists of the comb inductance and many mutual inductances. Each component of the parasitic resistance and inductance show different degrees of dependence on the finger length and on the number of fingers. The substrate network parameters also have optimum points. As such, the geometric dependence of the characteristics of the MOM capacitor is investigated and the optimum layout in the constant-capacitance case is proposed by calculating the results of the model. The proposed MOM capacitor structures for 50fF at f =60GHz are L =5μm with M =3, and, L =2μm with M =5 and that for 100fF at f =30GHz are L =9μm with M =3, and L =4μm with M =5. The target process is 65-nm CMOS.

Small delay caused by a resistive open is difficult to test since circuit delay varies depending on various factors such as process variations and crosstalk even in fault-free circuits. We consider the problem of discriminating a resistive open by anomaly detection using delay distributions obtained by the effect of various input signals provided to adjacent lines. We examined the circuit delay in a fault-free circuit and a faulty circuit by applying electromagnetic simulator and circuit simulator for a line structure with adjacent lines under consideration of process variations. The effectiveness of the method that discriminates a resistive open is shown for the results obtained by the simulation.

We present a smart steering wheel that detects the gripping position and area, as well as the distance to the approaching driver's hands by measuring the resonant frequency and its resistance value in an LCR circuit composed of the floating capacitance between the gripping hand and the electrode of the steering, and the body resistance. The resonant frequency measurement provides a high sensitivity that enables the estimation of the distance to the approaching hand, the gripping area of a gloved hand, and for covering the steering surface with any type of insulating material. This system can be applied for drowsiness detection, driving technique improvements, and for customization of the driving settings.

This study is aimed at clarifying the mechanism of wear process for Ag plating. The samples of different hardness Ag plating on copper alloys were prepared as coupon and embossment specimens, which simulated terminal contacts. During the sliding test, the contact resistance and the friction coefficient versus sliding distance are measured. The surface observation and surface roughness of the Ag films after wear tests were investigated. As results, the hard Ag plating film (120 Hv) exhibited higher contact resistance comparing to the soft Ag plating film (80 Hv). The soft Ag film delivered wider wear trace on coupon specimens compared to the hard one. Moreover, the observation of tribofilms formed on the Ag films after wear tests suggested that a mixed-type of adhesive and abrasive wears occurred for both of soft and hard Ag films. Furthermore, the fretting corrosion resistance of Ag plating samples with different hardness was also investigated. As results, the wear resistance of hard Ag film was stronger than that of soft Ag film.

At the present time, as downsizing of connectors causes thin gold plated layer and low contact load, serious problem of degradation of contact resistance property is induced. For these contacts, corrosion of the contacts surface under environment and high temperature as soldering and reflow process should be existed. Oxidation of base metal atoms which are diffused from under layer and additives occurs. Contact resistance increases for both surface contamination and low contact load. In order to resolve these problems and wear of surface, application of contact lubricants is useful and effective. However, degradation of the lubricants under such reflow process as high temperature possibly occurs. Therefore, in this study, from view point of change of lubricant quality as viscosity, weight loss, polymerization, oxidation and molecular orientation were clarified. For increase in contact resistance, orientation of lubricant molecular acts as important factor was found. The other factors of the lubricant hardly does not effect on contact resistance.

This paper proposes 0-1-A-Ā LUT, a new programmable logic using atom switches, and a delay-optimal mapping algorithm for it. Atom switch is a non-volatile memory device of very small geometry which is fabricated between metal layers of a VLSI, and it can be used as a switch device of very small on-resistance and parasitic capacitance. While considerable area reduction of Look Up Tables (LUTs) used in conventional Field Programmable Gate Arrays (FPGAs) has been achieved by simply replacing each SRAM element with a memory element using a pair of atom switches, our 0-1-A-Ā LUT achieves further area and delay reduction. Unlike the conventional atom-switch-based LUT in which all k input signals are fed to a MUX, one of input signals is fed to the switch array, resulting area reduction due to the reduced number of inputs of the MUX from 2k to 2k-1, as well as delay reduction due to reduced fanout load of the input buffers. Since the fanout of this input buffers depends on the mapped logic function, this paper also proposes technology mapping algorithms to select logic function of fewer number of fanouts of input buffers to achieve further delay reduction. From our experiments, the circuit delay using our k-LUT is 0.94% smaller in the best case compared with using the conventional atom-switch-based k-LUT.

In this paper, we have investigated the characteristics of PdYb-silicide layer formed by the silicidation of Pd/Yb/n-Si(100) stacked structures for the first time. Pd (12-20 nm)/Yb (0-8 nm) stacked layers were deposited on n-Si(100) substrates by the RF magnetron sputtering at room temperature. Then, 10 nm-thick HfN encapsulating layer was deposited at room temperature. Next, silicidation was carried out by the RTA at 500°C/1 min in N2 followed by the selective etching. From the J-V characteristics of fabricated Schottky diode, Schottky barrier height (SBH) for electron was reduced from 0.73 eV of Pd2Si to 0.4 eV of PdYb-silicide in case the Pd/Yb thicknesses were 14/6 nm, respectively.

We have studied the formation of Ti-nanodots (NDs) by remote H2 plasma (H2-RP) exposure and investigated how the embedding of Ti-NDs affects the resistive switching properties of Si-rich oxides (SiOx) because it is expected that NDs will trigger the formation of the conductive filament path in SiOx. Ti-NDs with an areal density as high as 1011 cm-2 were fabricated by exposing a Ge/Ti stacked layer to the H2-RP without external heating, and changes in the chemical structure of Ge/Ti stacked layer with the Ti-NDs formation were evaluated by using hard x-ray photoemission spectroscopy (HAXPES) and x-ray photoelectron spectroscopy (XPS). Resistive switching behaviors of SiOx with Ti-NDs were measured from current-voltage curves and compared to the results obtained from samples of SiOx with a Ti thin layer.

A comprehensive model is presented for estimating the bit error rate (BER) of write disturbance in a resistive memory composed of a cross-point array. While writing a datum into the selected address, the non-selected addresses are biased by word-line (WL) and bit-line (BL). The stored datum in the non-selected addresses will be disturbed if the bias is large enough. It is necessary for the current flowing through the non-selected address to be calculated in order to estimate the BER of the write disturbance. Since it takes a long time to calculate the current flowing in a large-scale cross-point array, several simplified circuits have been utilized to decrease the calculating time. However, these simplified circuits are available to the selected address, not to the non-selected one. In this paper, new simplified circuits are proposed for calculating the current flowing through the non-selected address. The proposed and the conventional simplified circuits are used, and on that basis the trade-off between the write disturbance and the write error is discussed. Furthermore, the error correcting code (ECC) is introduced to improve the trade-off and to provide the low-cost memory chip matching current production lines.

This paper focus on the development of a single portable roadside magnetic sensor for vehicle classification. The magnetic sensor is a kind of anisotropic magnetic device that do not require to be embedded in the roadway-the device is placed next to the roadway and measure traffic in the immediately adjacent lane. A novel feature extraction and comparison approach is presented for vehicle classification with a single magnetic sensor, which is based on four different feature sets extracted from the detected magnetic signal. Furthermore, vehicle classification has been achieved with three common classification algorithms, including support vector machine, k-nearest neighbors and back-propagation neural network. Experimental results have demonstrated that the Peak-Peak feature set with back-propagation neural network approach performs much better than other approaches. Besides, the normalization technology has been proved it does work.

The electrical lubricants have been accepted to reduce friction of contacts and to prevent degradation of contact resistance. However, as the lubricant has an electrical insulation property it seems that application to contact surface is unsuitable for contact resistance. These mechanisms in contact interfaces have not fully understood. In this paper, relationships between contact resistance and contact load were examined with both clean and lubricated surfaces. Orientation of the lubricant molecules was observed by high magnification images of STM and AFM. There was no difference in contact resistance characteristics for both clean and lubricated surfaces in spite of lubricants thickness. The molecules were orientated perpendicular to the surface. This fact turns over an established theory of adsorption of non-polar lubricant to surface.

We have investigated PtHf silicide formation utilizing a developed PtHf-alloy target to realize low contact resistivity for the first time. A 20 nm-thick PtHf-alloy thin film was deposited on the n-Si(100) by RF magnetron sputtering at room temperature. Then, silicidation was carried out by rapid thermal annealing (RTA) system at 450-600°C/5 min in N2/4.9%H2 ambient. The PtHf-alloy silcide, PtHfSi, layers were successfully formed, and the Schottky barrier height (SBH) for electron of 0.45 eV was obtained by 450°C silicidation. Furthermore, low contact resistivity was achieved for fabricated PtHSi such as 8.4x10-8 Ωcm2 evaluated by cross-bridge Kelvin resistor (CBKR) method.

In this work, the bias polarity dependent resistive switching behaviors in Cu/Si3N4/p+ Si RRAM memory cell have been closely studied. Different switching characteristics in both unipolar and bipolar modes after the positive forming are investigated. The bipolar switching did not need a forming process and showed better characteristics including endurance cycling, uniformity of switching parameters, and on/off resistance ratio. Also, the resistive switching characteristics by both positive and negative forming switching are compared. It has been confirmed that both unipolar and bipolar modes after the negative forming exhibits inferior resistive switching performances due to high forming voltage and current.

A novel activation method for a B dopant implanted in a Si substrate using a soft X-ray undulator was examined. As the photon energy of the irradiated soft X-ray approached the energy of the core level of Si 2p, the activation ratio increased. The effect of soft X-ray irradiation on B activation was remarkable at temperatures lower than 400°C. The activation energy of B activation by soft X-ray irradiation (0.06 eV) was lower than that of B activation by furnace annealing (0.18 eV). The activation of the B dopant by soft X-ray irradiation occurs at low temperature, although the activation ratio shows small values of 6.2×10-3 at 110°C. The activation by soft X-ray is caused not only by thermal effects, but also electron excitation and atomic movement.

A cryptographic hash is an important tool in the area of a modern cryptography. It comprises a compression function, where the compression function can be built by a scratch or blockcipher. There are some familiar schemes of blockcipher compression function such as Weimar, Hirose, Tandem, Abreast, Nandi, ISA-09. Interestingly, the security proof of all the mentioned schemes are based on the ideal cipher model (ICM), which depends on ideal environment. Therefore, it is desired to use such a proof technique model, which is close to the real world such as weak cipher model (WCM). Hence, we proposed an (n, 2n) blockcipher compression function, which is secure under the ideal cipher model, weak cipher model and extended weak cipher model (ext.WCM). Additionally, the majority of the existing schemes need multiple key schedules, where the proposed scheme and the Hirose-DM follow single key scheduling property. The efficiency-rate of our scheme is r=1/2. Moreover, the number of blockcipher call of this scheme is 2 and it runs in parallel.

Patch clamp measurement technique is one of the most important techniques in the field of electrophysiology. The elucidation of the channels, nerve cells, and brain activities as well as contribution of the treatment of neurological disorders is expected from the measurement of ion current. A current-to-voltage converter, which is the front end circuit of the patch clamp measurement system is fabricated using 0.18µm CMOS technology. The current-to-voltage converter requires a resistance as high as 50MΩ as a feedback resistor in order to ensure a high signal-to-noise ratio for very small signals. However, the circuit becomes unstable due to the large parasitic capacitance between the poly layer and the substrate of the on-chip feedback resistor and the instability causes the peaking at lower frequency. The instability of a current-to-voltage converter with a high-resistance as a feedback resistor is analyzed theoretically. A compensation circuit to stabilize the amplifier by driving the N-well under poly resistor to suppress the effect of parasitic capacitance using buffer circuits is proposed. The performance of the proposed circuit is confirmed by both simulation and measurement of fabricated chip. The peaking in frequency characteristic is suppressed properly by the proposed method. Furthermore, the bandwidth of the amplifier is expanded up to 11.3kHz, which is desirable for a patch clamp measurement. In addition, the input referred rms noise with the range of 10Hz ∼ 10kHz is 2.09 Arms and is sufficiently reach the requirement for measure of both whole-cell and a part of single-channel recordings.

A gold coated carbon nanotubes composite was used as a contact material in Micro-Electrical-Mechanical-System (MEMS) switches. The switching contact was tested under typical conditions of MEMS relay applications: load voltage of 4 V, contact force of 1 mN, and load current varied between 20-200 mA. This paper focuses on the wear process over switching lifetime, and the dependence of the wear area on the current is discussed. It was shown that the contact was going to fail when the wear area approached the whole contact area, at which point the contact resistance increased sharply to three times the nominal resistance.

This work addresses two key topics in the field of energy harvesting and wireless power transfer. The first is the optimum signal design for improved RF-DC conversion efficiency in rectifier circuits by using time varying envelope signals. The second is the design of rectifiers that present reduced sensitivity to input power and output load variations by introducing resistance compression network (RCN) structures.

Ni nanodots (NDs) used as nano-scale top electrodes were formed on a 10-nm-thick Si-rich oxide (SiO$_{mathrm{x}}$)/Ni bottom electrode by exposing a 2-nm-thick Ni layer to remote H$_{2}$-plasma (H$_{2}$-RP) without external heating, and the resistance-switching behaviors of SiO$_{mathrm{x}}$ were investigated from current-voltage ( extit{I--V}) curves. Atomic force microscope (AFM) analyses confirmed the formation of electrically isolated Ni NDs as a result of surface migration and agglomeration of Ni atoms promoted by the surface recombination of H radicals. From local extit{I--V} measurements performed by contacting a single Ni ND as a top electrode with a Rh coated Si cantilever, a distinct uni-polar type resistance switching behavior was observed repeatedly despite an average contact area between the Ni ND and the SiO$_{mathrm{x}}$ as small as $sim$ 1.9 $ imes$ 10$^{-12}$cm$^{2}$. This local extit{I--V} measurement technique is quite a simple method to evaluate the size scalability of switching properties.

We investigate the origin of non-ideal transfer characteristics in graphene-based three-branch nano-junction (TBJ) devices. Fabricated graphene TBJs often show asymmetric nonlinear voltage transfer characteristic, although symmetric one should appear ideally. A simple model considering the contact resistances in two input electrodes is deduced and it suggests that the non-ideal characteristic arises from inequality of the metal-graphene contact resistances in the inputs. We fabricate a graphene TBJ device with electrically equal contacts by optimizing the contact formation process and almost ideal nonlinear characteristic was successfully demonstrated.