scholarly journals Fast Fourier transform and multi-Gaussian fitting of XRR data to determine the thickness of ALD grown thin films within the initial growth regime

2020 ◽  
Vol 117 (21) ◽  
pp. 213106
Author(s):  
Michaela Lammel ◽  
Kevin Geishendorf ◽  
Marisa A. Choffel ◽  
Danielle M. Hamann ◽  
David C. Johnson ◽  
...  
Keyword(s):  
Thin Films ◽  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Initial Growth ◽  
Gaussian Fitting ◽  
Growth Regime

scholarly journals Roughness in lubricated rolling contact: The dry contact limit

2007 ◽  
Vol 221 (7) ◽  
pp. 787-791 ◽  
Author(s):  
A. V. Olver ◽  
D Dini
Keyword(s):  
Thin Films ◽  
Fourier Transform ◽  
Film Thickness ◽  
Fast Fourier Transform ◽  
Elastohydrodynamic Lubrication ◽  
Fourier Component ◽  
Rolling Contact ◽  
Perturbation Model ◽  
Rolling Contacts ◽  
Dry Contact

A difficulty with the standard fast Fourier transform (FFT) perturbation model of roughness in lubricated rolling contacts is that it does not necessarily converge towards the elastic case as the film thickness is reduced; rather it leads to a situation in which all the roughness is completely flattened. This is rarely the case for real engineering surfaces. Here, it is shown that this difficulty can be avoided by carrying out a Fourier transform of the elastostatically flattened roughness and using the resulting (complex) amplitude as the low-film thickness limit of each Fourier component in the elastohydrodynamic lubrication (EHL) analysis. Results give a plausible convergence to the elastostatic solution, which is nevertheless consistent with the expected near-full-film EHL behaviour and which becomes identical to the earlier model for roughness that, statically, can be fully flattened. As expected, hydrodynamic action persists at the finest scale, even for very thin films.

scholarly journals The measurement of anisotropic stress in obliquely-deposited thin films by fast Fourier transform and Gaussian filter

2011 ◽  
Vol 19 ◽  
pp. 21-26 ◽  
Author(s):  
Chuen-Lin Tien ◽  
Tsai-Wei Lin ◽  
Shiao-Shan Jyu ◽  
Hung-Da Tseng ◽  
Chern-Sheng Lin ◽  
...  
Keyword(s):  
Thin Films ◽  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Gaussian Filter ◽  
Anisotropic Stress

The measurement of surface roughness of optical thin films based on fast Fourier transform

2009 ◽  
Vol 517 (17) ◽  
pp. 5110-5115 ◽  
Author(s):  
Chuen-Lin Tien ◽  
Huei-Min Yang ◽  
Ming-Chung Liu
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Fourier Transform ◽  
Fast Fourier Transform

Study the Order of Morphology Self-Assembled Triblock Copolymer Thin Films by FFT of the AFM Images

2007 ◽  
Author(s):  
Yongzhi Cao ◽  
Shen Dong ◽  
Yingchun Liang ◽  
Tao Sun ◽  
Xuesen Zhao
Keyword(s):  
Thin Films ◽  
Fourier Transform ◽  
Block Copolymer ◽  
Fast Fourier Transform ◽  
Diffraction Pattern ◽  
Self Assembly ◽  
Order Parameter ◽  
Triblock Copolymer ◽  
Perfect System ◽  
Imperfect System

A variety of block copolymer thin films with well-ordered nanostructures, which can be employed as templates for nanotechnologies including nanostructure membranes, nanoparticle synthesis, photonic crystal, and high-density information storage media, can be realized simply and at low cost by self-assembly. Long range ordering of morphology is paramount to realize applications of self-assembled block copolymer thin films in nanotechnologies. A better understanding of what parameters affect the ordering process can lead to the production of highly ordered arrays of nanostructures. In this paper, in order to effectively analyze the improvement in ordering, the Fast Fourier transform (FFT) analysis of the AFM images is used. Fast Fourier transform provide a mathematical analysis of the image that is similar to producing a diffraction pattern. From this “diffraction pattern” information on the order in the system can be obtained. Moreover, calculating an ordering parameter from the FFT provides a quantitative measure of the order present in the polymer template. The order parameter is calculated using equations which were tested against a manufactured perfect system and imperfect system to ensure that a perfect system would provide an order parameter of 1 and an imperfect system would create an order parameter of 0. The results show that the method is reasonable and effective to analyze the improvement in ordering that is achieved by using solvent annealing. Furthermore, the method can be used to understand the parameters in triblock copolymer thin film self-assembly process that create the most well ordered system.

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