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It is vital to have an exclusive modification in semiconductor production process because of meeting differentiated customer demands in dynamic and competitive global minuscule semiconductor technology market and the highly complex fabrication process. In this paper, we propose a control system based on the dynamic mixed-effect least-square support vector regression (LS-SVR) control system for overlay error compensation with stochastic metrology delay to minimize the misalignment of the patterning process. Moreover, for the stability of the control system in the presence of metrology delay and to deal with nonlinearity among the overlay factors, the novel Lyapunov-based kernel function is merged with the LS-SVR controller. The proposed controller’s operation has been validated and implemented by a major semiconductor manufacturer in Taiwan. The experiments are verified that mixed-effect LS-SVR controller has the higher validity and higher efficiency in comparison with the exponentially weighted moving average (EWMA) and threaded EWMA controllers which had been previously implemented at the company or applied in similar studies. Note to Practitioners—Due to high production complexity in semiconductor manufacturing process, a meticulous and intelligent process control is needed to achieve higher throughput and customer satisfaction. Monitoring a complex system is challenging because the process components and variables operate autonomously and interoperate with other manufacturing segments. This paper proposes a novel run-to-run (R2R) control system to compensate the overlay error during the photolithography process that efficiently deals with the high-mixed manufacturing environment and metrology delay. [ABSTRACT FROM AUTHOR]

Abstract: Increasing our understanding of typhoon movements remains a priority in the western North Pacific. In this study, the trajectories of typhoons that affected Taiwan between 1986 and 2010 are used for clustering, where each trajectory consists of 6-hourly latitude-longitude positions over two days. We compare the performance of four statistical clustering methods, namely, k-means clustering, fuzzy c-means (FCM) clustering, hierarchical clustering, and normalized cut techniques. The results show that the FCM technique provides sufficient cluster efficiency with a relatively high degree of goodness of fit. FCM identifies six clusters according to the minimum coefficients of variation (CV). The hotspots of the typhoon centers in each cluster are determined by kernel density estimation (KDE). Moreover, the typhoon track belongs to six clusters with different membership degrees in FCM. The typhoon track density map is estimated by combining the KDE hotspot maps associated with the FCM weights. The information could be used in planning for disaster management. [Copyright &y& Elsevier]

Seismic attenuation parameters in Taiwan have been obtained by using a modified "MultipleLapse Time Window Analysis" approach in order to take into account the scatteringanisotropy. MLTWA method exploits the spatio-temporal dependence of the ratio betweencoherent and incoherent seismic intensity to determine the scattering and absorptionproperties of a heterogeneous medium. In addition to the mean free path l (or the scatteringquality factor Qsc), the seismic wave propagation is controlled by a parameter g(independent of l) which determines the angular redistribution of energy upon scattering(scattering anisotropy). Preferentially forward (resp. backward) scattering correspondsto g > 0 (resp. g < 0), with g = 0 for isotropic scattering. We use Monte-Carlosimulations to compute Green functions and sensitivity kernels for Qsc, Qi (absorptionquality factor) and g in media with an heterogeneous crust overlying a transparentmantle. We analyse seismic records of local earthquakes with magnitude greater than 3.5which occurred between 1994 and 2016. For each stations, we collect events withina radius of 100 km and a maximum depth of 40 km. About 350000 waveformswith a S/N ratio greater than 4 in the coda are selected. Seismic energy in three15 s time windows from the S-wave arrival are measured in 3 frequency bands(1-2, 2-4,4-8 Hz). To account for site amplification and source amplitude, wenormalize observed energy by the average energy in a late coda window at 65 s fromthe origin time of the earthquakes. For every station, we analyse the normalizedenergy in the three time widows as a function of the hypocentral distance. In order todetermine the attenuation parameters Qsc−1, Qi−1 and g with related errors, weimplement a Levenberg-Marquardt algorithm. To guide the inversion, we use thesensitivity kernels for the attenuation parameters computed with our Monte-Carloapproach. Overall, Taiwan is more attenuating than most orogens with a mean effective scatteringloss (Qsc∗)−1 = Qsc−1(1 − g) about 0.012 and a mean intrinsic absorption Qi−1 about0.009 at 1.5 Hz. Our maps reveals strong lateral variations of attenuation with scale lengthfrom 10 to 100 km. Scattering loss (Qsc∗)−1 varies over more than one order of magnitudeacross Taiwan (between 0.0022 and 0.16 at 1.5 Hz). By contrast, absorption fluctuations areabout 30%. The more attenuating zones are the Coastal Range and the Costal Plain wherescattering dominates over absorption at low frequency, and inversely at high frequency. Theseregions are also characterized by strong backscattering (g < −0.85) at 1.5 Hz and ratherhigh V P∕V S ratio. Scattering becomes much more isotropic at high frequency.We speculate that the observed strong backscattering at low frequency is relatedto strong impedance fluctuations in the crust induced by the presence of fluids. [ABSTRACT FROM AUTHOR]