Hf-doped and NH/sub 3/-nitrided high-K gate dielectric thin film with least drain current degradation and flatband voltage shift

A novel technique to form high-K dielectric of HfSiON by doping base oxide with Hf and nitridation with NH/sub 3/, sequentially, is proposed. The HfSiON gate dielectric demonstrates excellent device performances such as only 10% degradation of saturation drain current and almost 45 times of magnitude reduction in gate leakage compared with conventional SiO/sub 2/ gate at the approximately same equivalent oxide thickness. Additionally, negligible flatband voltage shift is achieved with this technique. Time-dependent dielectric breakdown tests indicate that the lifetime of HfSiON is longer than 10 years at V/sub dd/=2 V.     

Dynamic behavior of a distributed incinerator power system under output power variation

In Taiwan, the sales revenues of power generation from incinerator power plants with heat recovery power generation sold to the power company were up to NT$4.5bn, making the incinerator power generation play an important role in reduction of impact on environment and substitution of energy in power generation. Studying the dynamic behavior of incinerator power systems under output power variation is thus an essential task for the scheduling, operation, and expansion of incinerator power plants, such as, for cooperating with a scheduling program based on pricing signals to capture energy trading timing economically and to operate the incinerator power system securely. Although there are many studies on incinerator power generation, they seldom discuss the power generation system characteristics. In this paper, mathematical dynamic models for a distributed incinerator power system were derived and implemented using Matlab/Simulink, and dynamic characteristics of the system were further simulated and discussed under two operating modes: increment and decrement of power generation. These developed models can provide dynamic characteristics for these two modes, serving as an important analytic tool for cooperating with a scheduling program based on pricing signals to capture energy trading timing economically and to operate the incinerator power system securely. Copyright © 2014 John Wiley & Sons, Ltd.     

High-quality ultrathin (1.6 nm) nitride/oxide stack gatedielectrics prepared by combining remote plasma nitridation and LPCVDtechnologies

Ultrathin nitride/oxide (N/O) gate dielectric stacks with equivalent oxide thickness of 1.6 nm have been fabricated by combining remote plasma nitridation (RPN) and low pressure chemical vapor deposition (LPCVD) technologies. NMOSFETs with these gate stacks exhibit good interface properties, improved subthreshold characteristics, low off-state currents, enhanced reliability, and about one order of magnitude reduction in gate leakage current to their oxide counterparts     

A comprehensive note on “Lot‐sizing decisions for deteriorating items with two warehouses under an order‐size‐dependent trade credit”

To reduce inventory and increase sales, the supplier frequently offers the retailer a permissible delay in payments if the retailer orders more than or equal to a predetermined quantity. In 2012, Liao et al. proposed an economic order quantity model for a retailer with two warehouses when the supplier offers a permissible delay linked to order quantity. In this paper, we attempt to overcome some shortcomings of their mathematical model. Then, we apply some existing theoretical results in fractional convex programs to prove that the annual total variable cost is pseudoconvex. Hence, the optimal solution exists uniquely, which simplifies the search for the global minimum solution to a local minimum solution. Finally, we run a couple of numerical examples to illustrate the problem and compare the optimal solutions between theirs and ours.     

A novel method to improve cell endurance window in source-side injection split gate flash memory

To enhance cell endurance window of a split gate flash memory, we used a ramp pulse with long rising time to replace the conventional square pulse for programming. The change is based on the study of the electric field at electron injection point (E_G) related to programming time. Statistic measurements on various samples including different technologies, cell locations (even or odd) and rise times were done. The results confirm that the read currents shift under erase state (ΔI_r1) could be improved significantly with an acceptable programming speed by the proposed method.For example, as increasing the rising time from 0.1 μs to 20 μs for the conventional square pulse and the ramp pulse respectively, after 1 M cycling the ΔI_r1 is reduced from 64.8% to 36.2% with an acceptable minimum programming time of 12.5 μs.     

Heteroepitaxial silicon-carbide nitride films with different carbon sources on silicon substrates prepared by rapid-thermal chemical-vapor deposition

Cubic crystalline silicon-carbon nitride (Si_1−x−yC_xN_y) films have been grown successfully using various carbon sources by rapid-thermal chemical-vapor deposition (RTCVD). The characteristics of the Si_1−x−yC_xN_y films grown with SiH₃CH₃, C₂H₄, and C₃H₈ are examined and compared by x-ray photoelectron spectroscopy (XPS) spectra, scanning electron microscopy (SEM) images, and transmission electron microscopy (TEM) patterns. The XPS spectra show that the differences of chemical composition and chemical-bonding state are co-related to the C bonding type of the different carbon source. The SEM images and TEM analysis indicate that the better Si_1−x−yC_xN_y film can be obtained using C₃H₈ gas as the carbon source. In addition, correlations between the growing stages to the microstructure of the cubic-crystalline Si_1−x−yC_xN_y films have been illustrated in detail.     

Design and implementation of 1‐D median filter with variable window size

Abstract

The design and implementation of a one‐dimensional median filter is presented. The algorithm determines the median of a given set of samples W based on bit‐sequential extraction. The circuit is designed to operate on 8‐bit sample sequences. The structure of the circuit is very efficient in its hardware requirements of variable window size of seven, five or three samples.     

A reliable transmission protocol for ZigBee-based wireless patient monitoring

Patient monitoring systems are gaining their importance as the fast-growing global elderly population increases demands for caretaking. These systems use wireless technologies to transmit vital signs for medical evaluation. In a multihop ZigBee network, the existing systems usually use broadcast or multicast schemes to increase the reliability of signals transmission; however, both the schemes lead to significantly higher network traffic and end-to-end transmission delay. In this paper, we present a reliable transmission protocol based on anycast routing for wireless patient monitoring. Our scheme automatically selects the closest data receiver in an anycast group as a destination to reduce the transmission latency as well as the control overhead. The new protocol also shortens the latency of path recovery by initiating route recovery from the intermediate routers of the original path. On the basis of a reliable transmission scheme, we implement a ZigBee device for fall monitoring, which integrates fall detection, indoor positioning, and ECG monitoring. When the triaxial accelerometer of the device detects a fall, the current position of the patient is transmitted to an emergency center through a ZigBee network. In order to clarify the situation of the fallen patient, 4-s ECG signals are also transmitted. Our transmission scheme ensures the successful transmission of these critical messages. The experimental results show that our scheme is fast and reliable. We also demonstrate that our devices can seamlessly integrate with the next generation technology of wireless wide area network, worldwide interoperability for microwave access, to achieve real-time patient monitoring.     

Determination of deep ultrathin equivalent oxide thickness (EOT)from measuring flat-band C-V curve

In this letter, a novel and simple method to determine deep ultrathin oxide thickness by measuring the MOS capacitance under the flat-band condition is reported. The mechanism of this method has been profoundly studied. The results determined by this method show good agreement with those using capacitance-voltage (C-V) simulation, ellipsometer, and high-resolution transmission electromicroscopy (HRTM) analysis for thin oxides (2~3 nm). The thickness of pure oxide extracted by this method in this experiment can be down to 1.4 nm despite the obvious C-V distortion     

The hetero-epitaxial SiCN/Si MSM photodetector for high-temperature deep-UV detecting applications

A visible-blind ultraviolet (UV) photodetector (PD) with metal-semiconductor-metal (MSM) structure has been developed on a cubic-crystalline SiCN film. The cubic-crystalline SiCN film was deposited on Si substrate with rapid thermal chemical vapor deposition (RTCVD). The optoelectron performances of the SiCN-MSM PD have been examined by the measurement of photo and dark currents and the currents' ratio under various operating temperatures. The current ratio for 254-nm UV light of the detector is about 6.5 at room temperature and 2.3 at 200/spl deg/C, respectively. The results are better than the counterpart /spl beta/-SiC of 5.4 at room temperature, and less than 2 for above 100/spl deg/C, thus offering potential applications for low-cost and high-temperature UV detection.