scholarly journals Investigation of Stereometric and Fractal Patterns of Spin-Coated LuMnO3 Thin Films

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Igor Hernandes Gomes Marques ◽  
Robert Saraiva Matos ◽  
Yonny Romaguera-Barcelay ◽  
Ştefan Ţălu ◽  
Joaquim Agostinho Moreira ◽  
...  
Keyword(s):  
Thin Films ◽  
Spatial Patterns ◽  
Three Dimensional ◽  
Root Mean Square Roughness ◽  
Height Distribution ◽  
Si Substrates ◽  
Spatial Frequencies ◽  
Fractal Parameters ◽  
Fractal Patterns ◽  
Processing Techniques

In this paper, we have performed qualitative and quantitative analysis of LuMnO3 thin films surfaces, deposited by spin coating over Pt(111)/TiO2/SiO2/Si substrates, to evaluate their spatial patterns as a function of the film’s sintering temperature. Atomic force microscopy was employed to obtain topographic maps that were extensively analyzed via image processing techniques and mathematical tools. 3D (three-dimensional) topographical images revealed that films sintered at 650°C and 750°C presented the formation of smoother surfaces, while the film sintered at 850°C displayed a rougher surface with a root mean square roughness of ∼2.5 nm. On the other direction, the height distribution of the surface for all films has similar asymmetries and shape, although the film sintered using the highest temperature showed the lower density of rough peaks and a sharper peak shape. The advanced fractal parameters revealed that the film sintered at 850°C is dominated by low spatial frequencies, showing less spatial complexity, higher microtexture homogeneity, and uniform height distribution. These results suggest that the combination of stereometric and fractal parameters can be especially useful for identification of unique topographic spatial patterns in LuMnO3 thin films, helping in their implementation in technological applications, such as photovoltaic solar cells and information magnetic date storage and spintronic devices.

scholarly journals Fractal-Stereometric Correlation of Nanoscale Spatial Patterns of GdMnO3 Thin Films Deposited by Spin Coating

2021 ◽  
Vol 11 (9) ◽  
pp. 3886
Author(s):  
Yonny Romaguera-Barcelay ◽  
Ştefan Ţălu ◽  
Robert Saraiva Matos ◽  
Rosane Maria Pessoa Betânio Oliveira ◽  
Joaquim Agostinho Moreira ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Spatial Patterns ◽  
Spin Coating ◽  
Lower Surface ◽  
Physical Parameters ◽  
Si Substrates ◽  
Topographic Roughness ◽  
Atomic Force ◽  
Fractal Parameters

Multiferroic systems are of great interest for technological applications. To improve the fabrication of thin films, stereometric and fractal analysis of surface morphology have been extensively performed to understand the influence of physical parameters on the quality of spatial patterns. In this work, GaMnO3 was synthesized and thin films were deposited on Pt(111)/TiO2/SiO2/Si substrates using a spin coating apparatus to study the correlation between their stereometric and fractal parameters. All films were studied by X-ray diffraction (XRD), where the structure and microstructure of the film sintered at 850 °C was investigated by Rietveld refinement. Topographic maps of the films were obtained using an atomic force microscope (AFM) in tapping mode. The results show that the film sintered at 850 °C exhibited a clear formation of a GdMnO3 orthorhombic structure with crystallite size of ~14 nm and a microstrain higher than other values reported in the literature. Its surface morphology presented a rougher topography, which was confirmed by the height parameters. Topographic differences due to different asymmetries and shapes of the height distributions between the films were observed. Specific stereometric parameters also showed differences in the morphology and microtexture of the films. Qualitative rendering obtained by commercial image processing software revealed substantial differences between the microtextures of the films. Fractal and advanced fractal parameters showed that the film sintered at 850 °C had greater spatial complexity, which was due to their higher topographic roughness, lower surface percolation and greater topographic uniformity, being dominated by low dominant special frequencies. Our combination of stereometric and fractal measurements can be useful to improve the fabrication process by optimizing spatial patterns as a function of the sintering temperature of the film.

scholarly journals ROUGHNESS AND STRUCTURE OF InGaAsN THIN FILMS ON Si

2021 ◽  
pp. 106-114
Author(s):  
Олег Васильевич Девицкий
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Root Mean Square ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Root Mean Square Roughness ◽  
Mean Square ◽  
Force Microscopy ◽  
Si Substrates ◽  
Nitrogen Mixture

Методом импульсного лазерного напыления в атмосфере аргоно-азотной газовой смеси из мишени InGaAs впервые были получены тонкие пленки InGaAsN на подложках GaAs и Si. Мишень lnGaAs формировалась методом одноосного прессования из порошков GaAs и lnAs. Методами атомно силовой микроскопии и рентгеновской дифракции исследованы морфология поверхности и структура данных тонких пленок. Показано, что пленки InGaAsN на Si имеют средний размер кристалла 0,93 нм, а пленки и InGaAsN на GaAs - 0,99 нм. Определено, что уменьшение давления аргоно-азотной смеси при импульсном лазерном напылении тонких пленок InGaAsN на подложках GaAs и Si приводит к снижению значения среднеквадратичной шероховатости поверхности. Наименьшую среднеквадратическую шероховатость равную 0,25 нм имела тонкая пленка InGaAsN на подложке GaAs, полученная в вакууме, наибольшую среднеквадратическую шероховатость имела тонкая пленка InGaAsN на подложке Si, полученная при давления аргоно-азотной смеси от 10 Па - 19,37 нм. By the method of pulsed laser deposition in atmosphere of an argon-nitrogen gas mixture, for the first time thin InGaAsN films on GaAs and Si substrates were obtained from the InGaAs target. The InGaAs target was formed by uniaxial pressing from GaAs and InAs powders. The surface morphology and structure of these thin films are studied by atomic force microscopy and X-ray diffraction. It is shown that InGaAsN films on Si have an average crystal size of 0,93 nm, and InGaAsN films on GaAs of 0,99 nm. It is determined that a decrease in the pressure of an argon-nitrogen mixture during pulsed laser deposition of thin InGaAsN films on GaAs and Si substrates leads to a decrease in the value of the root- mean-square roughness of the surface. The smallest root-mean-square roughness equal to 0,25 nm had a thin InGaAsN film on a GaAs substrate obtained in vacuum, the largest root-mean- square roughness of 19,37 nm had a thin InGaAsN film on a Si substrate obtained at the argon-nitrogen mixture pressure of 10 Pa -.

scholarly journals Surface micromorphology characterization of PDI8-CN2 thin films on H-Si by AFM analysis

2020 ◽  
Vol 38 (2) ◽  
pp. 334-340 ◽  
Author(s):  
Ştefan Ţălu ◽  
Slawomir Kulesza ◽  
Miroslaw Bramowicz ◽  
Shahram Solaymani ◽  
Mihai Ţălu ◽  
...  
Keyword(s):  
Thin Films ◽  
Graphical Models ◽  
Surface Texture ◽  
Three Dimensional ◽  
Fractal Structures ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Surface Micromorphology ◽  
Semiconducting Compounds

AbstractA nanoscale investigation of three-dimensional (3-D) surface micromorphology of archetypical N, N0- bis (n-etyl) x:y, dicyanoperylene- 3, 4:9, 10 bis (dicarboximide) (PDI8-CN2) thin films on H-Si substrates, which are applicable in n-type semiconducting compounds, has been performed by using fractal analysis. In addition, surface texture characteristics of the PDI8-CN2 thin films have been characterized by using atomic force microscopy (AFM) operated in tapping-mode in the air. These analyses revealed that all samples can be described well as fractal structures at nanometer scale and their three dimensional surface texture could be implemented in both graphical models and computer simulations.

Interactions Between Al and Cr Thin Films

1976 ◽  
Vol 34 ◽  
pp. 638-639
Author(s):  
R. M. Anderson ◽  
T. M. Reith ◽  
M. J. Sullivan ◽  
E. K. Brandis
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Vacuum System ◽  
Processing Temperature ◽  
Diffusion Couples ◽  
Electronic Circuits ◽  
Intermetallic Formation ◽  
Si Substrates ◽  
Aluminum Silicon

Thin films of aluminum or aluminum-silicon can be used in conjunction with thin films of chromium in integrated electronic circuits. For some applications, these films exhibit undesirable reactions; in particular, intermetallic formation below 500 C must be inhibited or prevented. The Al films, being the principal current carriers in interconnective metal applications, are usually much thicker than the Cr; so one might expect Al-rich intermetallics to form when the processing temperature goes out of control. Unfortunately, the JCPDS and the literature do not contain enough data on the Al-rich phases CrAl7 and Cr2Al11, and the determination of these data was a secondary aim of this work.To define a matrix of Cr-Al diffusion couples, Cr-Al films were deposited with two sets of variables: Al or Al-Si, and broken vacuum or single pumpdown. All films were deposited on 2-1/4-inch thermally oxidized Si substrates. A 500-Å layer of Cr was deposited at 120 Å/min on substrates at room temperature, in a vacuum system that had been pumped to 2 x 10-6 Torr. Then, with or without vacuum break, a 1000-Å layer of Al or Al-Si was deposited at 35 Å/s, with the substrates still at room temperature.

Defects in β-SiC thin films grown on α-SiC substrates

1988 ◽  
Vol 46 ◽  
pp. 568-569
Author(s):  
Karren L. More
Keyword(s):  
Thin Films ◽  
Semiconductor Device ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Substrate Material ◽  
Growth Interface ◽  
Si Substrates ◽  
Thermal Expansion Coefficients ◽  
Device Applications ◽  
Expansion Coefficients

Beta-SiC is an ideal candidate material for use in semiconductor device applications. Currently, monocrystalline β-SiC thin films are epitaxially grown on {100} Si substrates by chemical vapor deposition (CVD). These films, however, contain a high density of defects such as stacking faults, microtwins, and antiphase boundaries (APBs) as a result of the 20% lattice mismatch across the growth interface and an 8% difference in thermal expansion coefficients between Si and SiC. An ideal substrate material for the growth of β-SiC is α-SiC. Unfortunately, high purity, bulk α-SiC single crystals are very difficult to grow. The major source of SiC suitable for use as a substrate material is the random growth of {0001} 6H α-SiC crystals in an Acheson furnace used to make SiC grit for abrasive applications. To prepare clean, atomically smooth surfaces, the substrates are oxidized at 1473 K in flowing 02 for 1.5 h which removes ∽50 nm of the as-grown surface. The natural {0001} surface can terminate as either a Si (0001) layer or as a C (0001) layer.

Three-Dimensional Structure of Rotavirus-Fab Complex

1990 ◽  
Vol 48 (1) ◽  
pp. 238-239
Author(s):  
B.V.V. Prasad ◽  
E. Marietta ◽  
J.W. Burns ◽  
M.K. Estes ◽  
W. Chiu
Keyword(s):  
Image Processing ◽  
Smooth Surface ◽  
Three Dimensional ◽  
Outer Shell ◽  
Dimensional Structure ◽  
Structural Studies ◽  
Cell Penetration ◽  
Electron Cryomicroscopy ◽  
Image Processing Techniques ◽  
Processing Techniques

Rotaviruses are spherical, double-shelled particles. They have been identified as a major cause of infantile gastroenteritis worldwide. In our earlier studies we determined the three-dimensional structures of double-and single-shelled simian rotavirus embedded in vitreous ice using electron cryomicroscopy and image processing techniques to a resolution of 40Å. A distinctive feature of the rotavirus structure is the presence of 132 large channels spanning across both the shells at all 5- and 6-coordinated positions of a T=13ℓ icosahedral lattice. The outer shell has 60 spikes emanating from its relatively smooth surface. The inner shell, in contrast, exhibits a bristly surface made of 260 morphological units at all local and strict 3-fold axes (Fig.l).The outer shell of rotavirus is made up of two proteins, VP4 and VP7. VP7, a glycoprotein and a neutralization antigen, is the major component. VP4 has been implicated in several important functions such as cell penetration, hemagglutination, neutralization and virulence. From our earlier studies we had proposed that the spikes correspond to VP4 and the rest of the surface is composed of VP7. Our recent structural studies, using the same techniques, with monoclonal antibodies specific to VP4 have established that surface spikes are made up of VP4.

Silicon layers grown over SiO2 by liquid phase epitaxy: Electron Microscopical study

1990 ◽  
Vol 48 (4) ◽  
pp. 566-567
Author(s):  
F. Banhart ◽  
F.O. Phillipp ◽  
R. Bergmann ◽  
E. Czech ◽  
M. Konuma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Plasma Etching ◽  
Liquid Phase Epitaxy ◽  
Three Dimensional ◽  
Microscopical Study ◽  
Sample Temperature ◽  
Structural Defects ◽  
Si Substrates ◽  
Etched Surface

Defect-free silicon layers grown on insulators (SOI) are an essential component for future three-dimensional integration of semiconductor devices. Liquid phase epitaxy (LPE) has proved to be a powerful technique to grow high quality SOI structures for devices and for basic physical research. Electron microscopy is indispensable for the development of the growth technique and reveals many interesting structural properties of these materials. Transmission and scanning electron microscopy can be applied to study growth mechanisms, structural defects, and the morphology of Si and SOI layers grown from metallic solutions of various compositions.The treatment of the Si substrates prior to the epitaxial growth described here is wet chemical etching and plasma etching with NF3 ions. At a sample temperature of 20°C the ion etched surface appeared rough (Fig. 1). Plasma etching at a sample temperature of −125°C, however, yields smooth and clean Si surfaces, and, in addition, high anisotropy (small side etching) and selectivity (low etch rate of SiO2) as shown in Fig. 2.

Interface motion during recrystallization of amorphous NiSi2

1990 ◽  
Vol 48 (4) ◽  
pp. 524-525
Author(s):  
J. L. Batstone ◽  
D.A. Smith
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Amorphous Film ◽  
Nucleation And Growth ◽  
Recrystallization Process ◽  
Amorphous Films ◽  
Interface Motion ◽  
Si Substrates ◽  
Spherical Caps ◽  
Crystal Interfaces

Recrystallization of amorphous NiSi2 involves nucleation and growth processes which can be studied dynamically in the electron microscope. Previous studies have shown thatCoSi2 recrystallises by nucleating spherical caps which then grow with a constant radial velocity. Coalescence results in the formation of hyperbolic grain boundaries. Nucleation of the isostructural NiSi2 results in small, approximately round grains with very rough amorphous/crystal interfaces. In this paper we show that the morphology of the rccrystallizcd film is dramatically affected by variations in the stoichiometry of the amorphous film.Thin films of NiSi2 were prepared by c-bcam deposition of Ni and Si onto Si3N4, windows supported by Si substrates at room temperature. The base pressure prior to deposition was 6 × 107 torr. In order to investigate the effect of stoichiomctry on the recrystallization process, the Ni/Si ratio was varied in the range NiSi1.8-2.4. The composition of the amorphous films was determined by Rutherford Backscattering.

Fabrication and Evaluation of SiO2 Thin Films on Si Substrates by Microwave Plasma in Various Conditions

2020 ◽  
Vol 140 (4) ◽  
pp. 186-192
Author(s):  
Shumpei Ogawa ◽  
Tatsuya Kuroda ◽  
Yasuyuki Katou ◽  
Hironori Haga ◽  
Hiroki Ishizaki
Keyword(s):  
Thin Films ◽  
Microwave Plasma ◽  
Si Substrates

scholarly journals Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Integrated Circuits ◽  
Film Thickness ◽  
Depth Range ◽  
Micro Electro Mechanical Systems ◽  
Si Substrates ◽  
Sio2 Thin Film ◽  
Average Grain Size

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

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