Detection and classification of defect patterns on semiconductor wafers

The detection of process problems and parameter drift at an early stage is crucial to successful semiconductor manufacture. The defect patterns on the wafer can act as an important source of information for quality engineers allowing them to isolate production problems. Traditionally, defect recognition is performed by quality engineers using a scanning electron microscope. This manual approach is not only expensive and time consuming but also it leads to high misidentification levels. In this paper, an automatic approach consisting of a spatial filter, a classification module and an estimation module is proposed to validate both real and simulated data. Experimental results show that three types of typical defect patterns: (i) a linear scratch; (ii) a circular ring; and (iii) an elliptical zone can be successfully extracted and classified. A Gaussian EM algorithm is used to estimate the elliptic and linear patterns, and a spherical-shell algorithm is used to estimate ring patterns. Furthermore, both convex and nonconvex defect patterns can be simultaneously recognized via a hybrid clustering method. The proposed method has the potential to be applied to other industries.     

Potential effects of ultrafiltration process and date powder on textural,sensory, bacterial viability,antioxidant properties and phenolic profile of dromedary Greek yogurt

The aim of this study was to improve textural and antioxidant capacity of dromedary yogurt using ultrafiltration process and date powder. Ultrafiltration increased total solids content of dromedary milk within the range considered optimal to develop yogurt. Texture profile of Greek yogurt fortified with date powder (GYD) improved considerably compared to control. Sample of GYD are more appealing to consumer than control. LC-ESI-MS analysis of GYD extracts allowed the identification of fifteen phenolic compounds, among which quinic acid and cirsiliol were found to be the major phenolic acid and flavonol, respectively. GYD exhibited the highest DPPH•-radical scavenging activity, Fe²⁺ chelating capacity and Fe³⁺ reducing power. The follow-up of physical and microbiological stability of GYD and control during cold storage showed that date powder significantly increased bacterial counts and decreased syneresis. Therefore, ultrafiltration and date powder could be valued as effective tool to solve the poor consistency of dromedary milk products.     

Investigation of OSN properties of PDMS membrane for the retention of dilute solutes with potential industrial applications

Few commercially available membranes can be used for organic solvent nanofiltration (OSN). Applying OSN in chemical industries is nevertheless of high interest to cut with energy consumption linked to solvent recycling and soluble catalysts recovery. A commercial membrane, PERVAP4060, was used to investigate the retention of dilute solutes in toluene feeds and to mimic metathesis medium. The studied solutes were R-BINAP a neutral polyaromatic molecule used in metathesis chemistry, tetraoctylammonium bromide (ToABr), a charged molecule used as a homogeneous catalyst and n-hexadecane. Retention of polar ToABr (95%) was higher than that of neutral R-BINAP (80%). The transfer mechanism, either pore flow or solution-diffusion, was discussed. All the results obtained suggested that the transport is governed by the solution-diffusion mechanism. The measured retentions could be explained in terms of solubility affinities and diffusion coefficients. The stability and performances of PERVAP4060 were well established, showing the strong potential for industrial applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48359.     

Design and performance evaluation of amplifier modules in stackable ROADMs for low-cost CWDM access networks

Coarse wavelength division multiplexing (CWDM) network has proven to be promising lower cost network architecture for a significant cost advantage over dense wavelength division multiplexing due to the lower cost of lasers and the filters used in CWDM modules. A compatible amplifier module having bidirectional amplification capability was deployed for introducing inside stackable reconfigurable optical add/drop multiplexers in realizing large-scale CWDM networks. The amplifier module for use in the bidirectional IP transmission confirmed that the insertion losses of the nodes and the losses of the fibers connecting the nodes can be compensated effectively, allowing the network administrator to increase the number of nodes and fiber length of the network. However, the noise generated from the amplification due to amplified spontaneous emission must be considered in network design issues. In this paper, optical power penalties due to the bidirectional amplification were estimated by conducting experimentation on minimum detectable power of optical transceivers. After analyzing the power penalty issue, an IP-over-CWDM ring network was implemented and the performance of network was evaluated by monitoring the power and packet transmissions before and after the amplifier module was turned on.     

Approximate expressions of packet error probability,throughput and delay for cognitive radio networks using fixed and adaptive transmit power

Telecommunication Systems - In this paper, we derive upper bound of Packet Error Probability (PEP), upper bound of delay and lower bound of throughput in cognitive radio networks. Our analysis is...     

Electronic,Magnetic, Electric and Magnetocaloric Properties of the Multiferroic Orthorhombic YMnO3

Journal of Superconductivity and Novel Magnetism - Multiferroic oxide materials have attracted much intention in recent years due to their application in different fields such as magnetic...     

An integrated cyber security risk management framework and risk predication for the critical infrastructure protection

Neural Computing and Applications - Cyber security risk management plays an important role for today’s businesses due to the rapidly changing threat landscape and the existence of evolving...     

Kernelized relative entropy for direct fault detection in industrial rotary kilns

The objective of this work is to use a 1‐dimensional signal that reflects the dissimilarity between multidimensional probability densities for detection. With the modified Kullback‐Leibler divergence, faults can be directly detected without any normality assumption or joint monitoring of related test statistics in different subspaces such as the T² and SPE in principal component analysis–based methods. To relieve the difficulty associated with asymptotic high‐dimensional density estimates, we have estimated the density ratio rather than the densities themselves. This can be done by approximating the density ratio with kernel basis functions and learn the weights from the available data. The developed algorithm is generic and can be applied to any industrial system as long as process historical data is available. As a case study, we apply this algorithm to a real rotary kiln in operation, which is an integral part of the cement manufacturing plant of Ain El Kebira, Algeria.