AFM STUDIES OF VARIOUS NIOBIUM AND ALUMINIUM THIN FILMS FOR THEIR USE IN JOSEPHSON JUNCTIONS

2001 ◽  
Vol 08 (06) ◽  
pp. 689-692
Author(s):  
SHAHZAD NASEEM

Nb thin films have been prepared with e-beam evaporation under UHV conditions, and by RF magnetron sputtering. Al thin films were deposited by resistive heating in the UHV chamber. The preparation of these films and the trilayers of Nb/AlO x /Nb are intended for their use in Josephson junctions. Surface studies of these films are undertaken by using an atomic force microscope in the noncontact mode. These studies have revealed that the sputter-deposited Nb film surface is smoother than that of the UHV e-beam evaporated with R rms values of 3.5 and 4.0 nm respectively. Al thin films have a very smooth surface, with an R rms value of only 0.9 nm. Consequently, UHV-evaporated Nb thin films deposited on top of Al thin films are smoother, with a surface roughness of 1.8 nm.

2001 ◽  
Vol 672 ◽  
Author(s):  
Jae Bin Lee ◽  
Sanghyon Kwack ◽  
Hyeong Joon Kim

ABSTRACTWe investigated the effect of substrate surface roughness on c-axis preferred orientation of ZnO films deposited by radio frequency (rf) magnetron sputtering. We used as substrates a bare Si(100), evaporated Au/Si(100), evaporated Al/Si(100), and sputtered Al/Si(100), of which rms roughness by atomic force microscope (AFM) were 0.127, 1.71, 2.11, and 6.5∼11.8 nm, respectively. The crystallinity and the c-axis preferred orientation of ZnO films strongly depended on the surface roughness of the used substrates.


1996 ◽  
Vol 433 ◽  
Author(s):  
T. B. Wu ◽  
J. M. Wu ◽  
C. M. Wu ◽  
M. J. Shyu ◽  
M. S. Chen ◽  
...  

AbstractHighly (100)-textured thin film of metallic LaNiO3 (LNO) was grown on the Pt/Ti/SiO2/Si substrates by rf magnetron sputtering at ˜300°C, which was used as a bottom electrode to prepare highly (100)-textured ferroelectric films. Examples on the deposition of PbTiO3, (Pbl−xLax)TiO3, Pb(Zr0.53Ti0.47)O3, Pb[(Mg1/3Nb2/3)1−xTix]O3, and (Ba1−xSrx)TiO3 thin films by rf magnetron sputtering or sol-gel method are shown. A reduction of temperature for perovskite phase formation can be achieved, especially for those difficult to crystallize. The surface roughness of the ferroelectric films is also improved as compared to that of films deposited on conventional Pt electrode. Although the electrical properties of the ferroelectric films are affected by the out-diffusion of LNO when a higher temperature was used in the preparation of the films, under an appropriate processing condition, the highly (100)-textured films can have satisfactory electrical characteristics for application. Moreover, the polarization-fatigue property can be also improved by the use of LNO electrode.


2019 ◽  
Vol 33 (15) ◽  
pp. 1950152 ◽  
Author(s):  
Jing Wu ◽  
Xiaofeng Zhao ◽  
Chunpeng Ai ◽  
Zhipeng Yu ◽  
Dianzhong Wen

To research the piezoresistive properties of SiC thin films, a testing structure consisting of a cantilever beam, SiC thin films piezoresistors and a Cr/Pt electrode is proposed in this paper. The chips of testing structure were fabricated by micro-electro-mechanical system (MEMS) technology on a silicon wafer with [Formula: see text]100[Formula: see text] orientation, in which SiC thin films were deposited by using radio-frequency (13.56 MHz) magnetron sputtering method. The effect of sputtering power, annealing temperature and time on the microstructure and morphology of the SiC thin films were investigated by the X-ray diffraction (XRD) and scanning electron microscopy (SEM). It indicates that a good continuity and uniform particles on the SiC thin film surface can be achieved at sputtering power of 160 W after annealing. To verify the existence of Si–C bonds in the thin films, X-ray photoelectron spectroscopy (XPS) was used. Meanwhile, the piezoresistive properties of SiC thin films piezoresistors were measured using the proposed cantilever beam. The test result shows that it is possible to achieve a gauge factor of 35.1.


2015 ◽  
Vol 1117 ◽  
pp. 139-142 ◽  
Author(s):  
Marius Dobromir ◽  
Radu Paul Apetrei ◽  
A.V. Rogachev ◽  
Dmitry L. Kovalenko ◽  
Dumitru Luca

Amorphous Nb-doped TiO2 thin films were deposited on (100) Si and glass substrates at room temperature by RF magnetron sputtering and a mosaic-type Nb2O5-TiO2 sputtering target. To adjust the amount of the niobium dopant in the film samples, appropriate numbers of Nb2O5 pellets were placed on the circular area of the magnetron target with intensive sputtering. By adjusting the discharge conditions and the number of niobium oxide pellets, films with dopant content varying between 0 and 16.2 at.% were prepared, as demonstrated by X-ray photoelectron spectroscopy data. The X-ray diffraction patterns of the as-deposited samples showed the lack of crystalline ordering in the samples. Surfaces roughness and energy band gap values increase with dopant concentration, as showed by atomic force microscopy and UV-Vis spectroscopy measurements.


2006 ◽  
Vol 321-323 ◽  
pp. 1336-1339
Author(s):  
Won Seok Choi ◽  
Young Park ◽  
Jin Hyo Boo ◽  
Junsin Yi ◽  
Byung You Hong

We investigated the structural and electrical properties of the 0.5% Ce-doped Ba(ZrxTi1-x)O3 (BZT) thin films with a mole fraction of x=0.2 and a thickness of 150 nm for the MLCC (Multilayer Ceramic Capacitor) application. Ce-doped BZT films were prepared on Pt/Ti/SiO2/Si substrates by a RF magnetron sputtering system as a function of Ar/O2 ratio and substrate temperature. X-ray diffraction patterns were recorded for the samples deposited with three different substrate temperatures. The thickness and the surface roughness of the films deposited with different Ar/O2 ratios were measured. The oxygen gas, which was introduced during the film deposition, had an influence on the growth rate and the roughness of the film. The surface roughness and dielectric constant of the Ce-doped BZT film varied with Ar to O2 ratios (5:1, 2:1, and 1:1) from 1.21 nm to 2.33 nm and 84 to 149, respectively. The Ce-doped BZT film deposited at lower temperature has small leakage current and higher breakdown voltage.


1994 ◽  
Vol 361 ◽  
Author(s):  
Kiyotaka Wasa ◽  
T. Satoh ◽  
K. Tab Ata ◽  
H. Adachi ◽  
Y. Ichikawa ◽  
...  

ABSTRACTUltrathin films of perovskite PbTiO3, 10–100nm thick, were epitaxially grown on miscut (001)SrTiO3 substrate by rf-magnetron sputtering at 600°C. The electron microscope and high resolution x-ray diffraction analysis suggested the evidence of epitaxial growth of (001)PbTiO3/(001)SrTiO3 with three dimensional crystal orientation. The stoichiometric film shows extremely smooth surface with the surface roughness less than 3nm. Deposition on a miscut substrate under stoichiometric conditions is essential to make continuous thin films of single crystal perovskite PbTiO3.


2021 ◽  
Author(s):  
srinivasa varaprsad H ◽  
sridevi P. V ◽  
Satya Anuradha M ◽  
Srinivas Pattipaka ◽  
pamu D

Abstract Perovskites are important composites in the area of multidisciplinary applications. It is achieved by carefully choosing and tuning the properties of the thin-film at the deposition. In this paper, ZnTiO3 (ZTO) thin-films were being deposited on quartz and N-Si substrates by RF magnetron sputtering. The thin-films were developed at room temperature, oxygen percentage levels varying from 0 to 100, and annealed at 600oC. The electrical, optical, morphological, and structural properties were analyzed as a function of oxygen mixing percentage (OMP). The crystallinity of the cubic structured ZTO thin-film is found to be high at 25 OMP, and it is gradually decreased with increased OMP. The surface morphology of the thin-film is observed, and roughness is measured from the atomic force microscope. Raman Spectroscopy investigated the phase formation and the vibrational modes of the thin-film with their spectral de-convolution. The ZTO thin-films optical properties were investigated using transmittance spectra. The ZTO thin-film indicated the highest refractive index of 2.46, at 633nm with optical bandgap values of 3.57 eV, with a thickness of 145nm and 25 OMP. The refractive index, thin-film thickness, and excitation coefficient were analyzed using the Swanepoel envelope technique. Electrical characteristics of ZTO thin-film are measured from the optimized conditions of the thin-film with conventional thermionic emission (TE) technique.


2013 ◽  
Vol 804 ◽  
pp. 3-7
Author(s):  
Chao Zhan ◽  
Wen Jian Ke ◽  
Xin Ming Li ◽  
Wan Li Du ◽  
Li Juan Wang ◽  
...  

Cubic ZnTiO3thin films have been prepared by radio frequency magnetron sputtering on n-type (100) Si substrate at different temperatures. The morphological and optical properties of ZnTiO3films in relation to substrate temperatures are investigated by spectroscopic ellipsometry (SE) and AFM as well as SEM in detail. X-ray diffraction (XRD) measurement shows that all the films have a cubic phase structure and the optimum substrate temperature to form crystalline ZnTiO3thin film is 250 °C. Through SEM and AFM, the particle size in thin films and film surface roughness increase with increasing the substrate temperature. Based on a parameterized TaucLorentz dispersion model, the optical constants and surface roughness of ZnTiO3films related to the substrate temperature are systematically extracted by SE measurement. The surface roughness of the film measured from AFM agrees well with result extracted from SE, which proved that the established SE model is reasonable. With increasing substrate temperature, the refractive index decreases and the main factor in determining the refractive index was deduced to be the surface roughness related to the film packing density. The extinction coefficient of the samples is close to zero, but increases slightly with the increase of the substrate temperature, which is due to the enhancement of scattering effect in the crystalline ZnTiO3film.


1989 ◽  
Vol 169 ◽  
Author(s):  
R. L. Meng ◽  
Y. Q. Wang ◽  
Y. Y. Sun ◽  
Li Gao ◽  
P. H. Hor ◽  
...  

AbstractThe synthesis parameters have been systematically examined for the in situ growth of high temperature superconducting Y‐Ba‐Cu‐0 thin films from a stoichiometric target by rf magnetron sputtering. By properly adjusting the deposition temperature, the total sputtering (O2+Ar)‐pressure and the O2‐partial pressure, we have reproducibly obtained 123 YBCO films with a zero resistivity temperature Tcz = 84 K and a transition width of 3 K°. The films so obtained have excellent surface morphology and a surface roughness better than ∼ 5 nm.


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