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This paper proposes a new cumulant-based algorithm to jointly estimate four-dimensional (4D) source parameters of multiple near-field narrowband sources. Firstly, this approach proposes a new cross-array, and constructs five high-dimensional Toeplitz matrices using the fourth-order cumulants of some properly chosen sensor outputs; secondly, it forms a parallel factor (PARAFAC) model in the cumulant domain using these matrices, and analyzes the unique low-rank decomposition of this model; thirdly, it jointly estimates the frequency, two-dimensional (2D) directions-of-arrival (DOAs), and range of each near-field source from the matrices via the low-rank three-way array (TWA) decomposition. In comparison with some available methods, the proposed algorithm, which efficiently makes use of the array aperture, can localize N − 3 sources using N sensors. In addition, it requires neither pairing parameters nor multidimensional search. Simulation results are presented to validate the performance of the proposed method.

Using the data of Chinese cross‐border mergers and acquisitions (M&As) from 2003 to 2017, we investigate the influence of the internal financial conditions of enterprises on the short‐term market performance of Chinese cross‐border M&As by applying improved DuPont financial analysis, an event study and regression analysis and further explore the moderating effect of payment method in Chinese cross‐border M&A. The findings are threefold. First, we observe significant positive cumulative abnormal returns (CARs) of Chinese cross‐border M&As, along with the underperformance of cross‐border M&As financed with pure cash payments compared to those financed with other payment methods. Second, the profitability and financial leverage of Chinese enterprises engaged in cross‐border M&As are significantly positively and significantly negatively correlated with CARs, respectively, while the impact of the operating capacity on CARs is limited. Finally, we note that the negative influence of financial leverage on CARs is enhanced in pure cash bids, which indicates that the payment method plays a prominent moderating role in the impact of financial leverage on the short‐term market performance of Chinese cross‐border M&As. Our result suggests that one reason for the underperformance of cross‐border M&As financed with pure cash payment compared to M&As financed with other payment methods is the negative effect of financial leverage, which is augmented in cross‐border M&As financed with pure cash payment.

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W CMP process plays an important role to form the contact W plug. We had faced a severe issue of W plug recess during W CMP process. In this paper, a solution to above issue will be reported. Firstly, the characteristic and mechanism of W plug recess in W CMP process will be elaborated. Secondly, an improved method to solve the issue will be described. The selection of buffing slurry plays a critical role to find the solution. Next, the impact of W plug recess on the electric performance in the whole integration scheme will be analyzed. In addition, the optimization process with the improved method for other post CMP performance, such as uniformity, oxide loss, W plug protrusion and defectivity etc. will be reported as well. In a summary, a corrosion free W CMP process has been achieved with the improvement in oxide buffing step of W CMP process. The contact resistant performance has been improved and the wafer yield has been significantly increased.