Development and Application of an Abrasive-Free Polishing Solution for Copper

MRS Bulletin ◽  
2002 ◽  
Vol 27 (10) ◽  
pp. 772-775 ◽  
Author(s):  
Masanobu Hanazono ◽  
Jin Amanokura ◽  
Yasuo Kamigata

AbstractAn abrasive-free polishing (AFP) solution for chemical–mechanical planarization (CMP) of copper films on semiconductor wafers has been developed to overcome such disadvantages of conventional CMP as dishing, erosion, Cu and oxide loss, and microscratching. Electrochemical methods are an effective way of understanding the role of each chemical component in the AFP solution in order to optimize its performance. Analysis of the reaction layer of Cu elucidates the reasons for the excellent results that have been obtained. By applying the AFP solution for Cu CMP in combination with a slurry for CMP of the metal barrier layer, seven-level multilayer Cu interconnections can be successfully fabricated.

2003 ◽  
Vol 65 (4) ◽  
pp. 478-488 ◽  
Author(s):  
V.S Chathapuram ◽  
T Du ◽  
K.B Sundaram ◽  
V Desai

2019 ◽  
Vol 15 (3) ◽  
pp. 198-206 ◽  
Author(s):  
Sarfaraz Ahmed Mahesar ◽  
Saeed Ahmed Lakho ◽  
Syed Tufail Hussain Sherazi ◽  
Hamid Ali Kazi ◽  
Kamran Ahmed Abro ◽  
...  

Background: Captopril is the synthetic dipeptide used as an angiotensin converting enzyme inhibitor. Captopril is used to treat hypertension as well as for the treatment of moderate heart failure. Analytical instrumentation and methodology plays an important role in pharmaceutical analysis. Methods: This review presents some important applications of electrochemical modes used for the analysis of captopril. So far captopril has been analyzed by using different bare and modified working electrodes with a variety of modifiers from organic and inorganic materials to various types of nano particles/materials. Results: This paper presents some of the methods which have been published in the last few years i.e. from 2003 to 2016. This review highlights the role of the analytical instrumentation, particularly electrochemical methods in assessing captopril using various working electrodes. Conclusion: A large number of studies on voltammetry noted by means of various bare and modified electrodes. Among all of the published voltammetric methods, DPV, SWV, CV and miscellaneous modes were trendy techniques used to analyze captopril in pharmaceutical formulations as well as biological samples. Electrodes modified with nanomaterials are promising sensing tools as this showed high sensitivity, good accuracy with precision as well as selectivity. In comparison to chromatographic methods, the main advantages of electrochemical methods are its cheaper instrumentation, lower detection limit and minimal or no sample preparation.


Author(s):  
Omar Arafat ◽  
Mark A Gregory

Femtocells are considered one of the ultimate solutions for the ever increasing demand in LTE-Advance. Recently, wireless industries have resorted to femtocell networks in order to enhance indoor coverage and quality of service since macro-antennas fail to reach these objectives. In enabling indoor home or enterprise users with mobile broadband solutions, role of femtocells are crucially important. While considering low cost solutions for higher coverage and data rate, femtocells apparently have one of the best potentials for indoor users. Due to the dense self-deployment of femtocells in a limited area, serious inter-femtocell interference (IFI) may cause, which consequently results in severe performance degradation. To mitigate the IFI and utilize spectrum resource more efficiently, this paper proposes a cluster based femtocell deployments along with a capacity based cognitive resource allocation scheme .Three different channel configurations in a hybrid access femtocell network are considered for performance analysis. The results of a performance analysis of the cluster based femtocell configurations in a priority based users’ network are presented.


Author(s):  
Karri Chiranjeevi ◽  
Umaranjan Jena ◽  
Sonali Dash

Linde-Buzo-Gray (LBG) Vector Quantization (VQ), technically generates local codebook after many runs on different sets of training images for image compression. The key role of VQ is to generate global codebook. In this paper, we present comparative performance analysis of different optimization techniques. Firefly and Cuckoo search generate a near global codebook, but undergoes problem when non-availability of brighter fireflies and convergence time is very high respectively. Hybrid Cuckoo Search (HCS) algorithm was developed and tested on four benchmark functions, that optimizes the LBG codebook with less convergence rate by taking McCulloch's algorithm based levy flight and variant of searching parameters. Practically, we observed that Bat algorithm (BA) peak signal to noise ratio is better than LBG, FA, CS and HCS in between 8 to 256 codebook sizes. The convergence time of BA is 2.4452, 2.734 and 1.5126 times faster than HCS, CS and FA respectively.


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