Surface Structure and Morphology of SrBi2Ta2O9 (SBT) Thin Films

1996 ◽  
Vol 440 ◽  
Author(s):  
Tingkai Li ◽  
Pete Zawadzki ◽  
Richard A. Stall ◽  
Chien-Hsiung Peng ◽  
Yongfei Zhu ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Surface Structure ◽  
Grain Growth ◽  
Phase Formation ◽  
Deposition Temperature ◽  
Electric Properties ◽  
Step Process ◽  
Structure And Morphology ◽  
Structure Morphology

AbstractSrBi2Ta2O9 (SBT) films have been prepared by MOCVD processes. The phase formation, surface structure, morphology and surface roughness of SBT films on Pt/Ti/SiO2/Si wafers were measured by XRD, SEM, AFM and ellipsometry. It was found that amorphous SBT formed below 500°C, amorphous and polycrystalline growth occurred successively between 500°C and 650°C. The surface roughness of the SBT thin films also increased with increasing deposition temperature. The AFM results showed the nucleation of SBT started by island formation, then continued across the surface of substrates at lower deposition temperatures. When the SBT film was deposited at higher temperatures, the nucleation and grain growth occurred at the same time, resulting in an inhomogencous structure and much higher surface roughness. Therefore, a two step process is used to improve surface roughness and interface mismatch between film and substrate. In addition, the relationships between surface structure, morphology and the electric properties of SBT thin films were also investigated.

Novel Mocvd Processes for Nanoscale Oxide Thin Films

1996 ◽  
Vol 446 ◽  
Author(s):  
Tingkai Li ◽  
Pete Zawadzkp ◽  
Richard A. Stall ◽  
Yongfei Zhu ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Integrated Circuits ◽  
Deposition Temperature ◽  
High Dielectric Constant ◽  
Ferroelectric Properties ◽  
Oxide Thin Films ◽  
High Quality ◽  
Step Process ◽  
High Dielectric

AbstractNanoscale oxide thin films such as Ba1‐xSrxTiO3 (BST), SrBi2Ta2O9 (SBT), and PbZr1‐xTixO3 (PZT) that have a high dielectric constant and excellent ferroelectric properties have been receiving greatly increased attention, especially for high density memories in next generation integrated circuits. However, with increasing deposition temperature the surface roughness of the films increases, which results in high leakage current, and when the thickness of oxide films is decreased, the apparent bulk‐like properties of thin films tend to worsen due to the increased influence of the interface. To solve these problems, novel MOCVD techniques, plasma enhanced deposition, and a two step process, were developed for high quality oxide thin films.

Highly Conductive and Optically Transparent Polycrystalline Iridium Oxide Thin Films Grown by Reactive Pulsed Laser Deposition

1997 ◽  
Vol 472 ◽  
Author(s):  
M.A. El Khakani ◽  
M. Chaker
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Deposition Temperature ◽  
Room Temperature ◽  
Optical Transmission ◽  
Ambient Pressure ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Structure Morphology ◽  
Quartz Substrates

ABSTRACTReactive pulsed laser deposition has been used to deposit IrO2 thin films on both SiO2 and fused quartz substrates, by ablating a metal iridium target in oxygen atmosphere. At a KrF laser intensity of about 1.7 × 109 W/cm2, IrO2 films were deposited at substrate deposition temperatures ranging from room-temperature to 700 °C under an optimum oxygen ambient pressure of 200 mTorr. The structure, morphology, electrical resistivity and optical transmission of the deposited films were characterized as a function of their deposition temperature (Td). High quality IrO2 films are obtained in the 400–600 °C deposition temperature range. They are polycrystalline with preferred orientations, depending on the substrate, and show a dense granular morphology. At a Td as low as 400 °C, highly conductive IrO2 films with room-temperature resistivities as low as (42±6) μΩ cm are obtained. Over the 300–600 °C Td range, the IrO2 films were found to exhibit a maximum optical transmission at 450 °C (∼ 45 % at 500 nm for 80 nm-thick films).

Buffer Layer Effects on the Structure and Morphology of SmCo/Cu Thin Films

2012 ◽  
Vol 476-478 ◽  
pp. 2415-2418
Author(s):  
Qi Ping Zhang ◽  
Qing Qing Fang ◽  
Wei Na Wang ◽  
Qing Rong Lv ◽  
Yan Mei Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Magnetic Properties ◽  
Buffer Layer ◽  
Annealing Time ◽  
Buffer Layers ◽  
Cu Films ◽  
Structure And Morphology ◽  
Different Thickness

In this paper, we investigated the structure of SmCo films with different thickness and the effects of Cr buffer layer on the structure and morphology of SmCo/Cu thin films. Our data revealed that the magnetic properties of the samples were enhanced by the crystallization of SmCo which was promoted by the optimized Cu underlayers. We also found that the surface roughness can be decreased by Cr layer and the texture can be improved by prolonging the annealing time for thick SmCo film. Thus, we concluded that the magnetic properties of SmCo/Cu films can be further optimized by varying the thickness of Cr buffer layers.

scholarly journals Growth of Atomic Layer Deposited Ruthenium and Its Optical Properties at Short Wavelengths Using Ru(EtCp)2 and Oxygen

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 413 ◽  
Author(s):  
Robert Müller ◽  
Lilit Ghazaryan ◽  
Paul Schenk ◽  
Sabrina Wolleb ◽  
Vivek Beladiya ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Optical Properties ◽  
Deposition Temperature ◽  
Film Growth ◽  
High Surface ◽  
Atomic Layer ◽  
Fused Silica ◽  
High Density ◽  
Adhesion Properties

High-density ruthenium (Ru) thin films were deposited using Ru(EtCp)2 (bis(ethylcyclopentadienyl)ruthenium) and oxygen by thermal atomic layer deposition (ALD) and compared to magnetron sputtered (MS) Ru coatings. The ALD Ru film growth and surface roughness show a significant temperature dependence. At temperatures below 200 °C, no deposition was observed on silicon and fused silica substrates. With increasing deposition temperature, the nucleation of Ru starts and leads eventually to fully closed, polycrystalline coatings. The formation of blisters starts at temperatures above 275 °C because of poor adhesion properties, which results in a high surface roughness. The optimum deposition temperature is 250 °C in our tool and leads to rather smooth film surfaces, with roughness values of approximately 3 nm. The ALD Ru thin films have similar morphology compared with MS coatings, e.g., hexagonal polycrystalline structure and high density. Discrepancies of the optical properties can be explained by the higher roughness of ALD films compared to MS coatings. To use ALD Ru for optical applications at short wavelengths (λ = 2–50 nm), further improvement of their film quality is required.

A Study of the In Situ Epitaxial Growth of the 123 Ybco Films from a Stoichiometric Target by Rf Magnetron Sputtering

1989 ◽  
Vol 169 ◽  
Author(s):  
R. L. Meng ◽  
Y. Q. Wang ◽  
Y. Y. Sun ◽  
Li Gao ◽  
P. H. Hor ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Magnetron Sputtering ◽  
Deposition Temperature ◽  
Rf Magnetron Sputtering ◽  
Transition Width ◽  
Ybco Films ◽  
Synthesis Parameters ◽  
Better Than

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.

scholarly journals Influence of Deposition Temperature on the Phase Evolution of HfNbTiVZr High-Entropy Thin Films

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 587 ◽  
Author(s):  
Stefan Fritze ◽  
Christian Koller ◽  
Linus von Fieandt ◽  
Paulius Malinovskis ◽  
Kristina Johansson ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Phase Formation ◽  
Deposition Temperature ◽  
Room Temperature ◽  
Phase Evolution ◽  
Peak Hardness ◽  
High Entropy ◽  
Hardness Increase ◽  
Bulk Alloys

In this study, we show that the phase formation of HfNbTiVZr high-entropy thin films is strongly influenced by the substrate temperature. Films deposited at room temperature exhibit an amorphous microstructure and are 6.5 GPa hard. With increasing substrate temperature (room temperature to 275 °C), a transition from an amorphous to a single-phased body-centred cubic (bcc) solid solution occurs, resulting in a hardness increase to 7.9 GPa. A higher deposition temperature (450 °C) leads to the formation of C14 or C15 Laves phase precipitates in the bcc matrix and a further enhancement of mechanical properties with a peak hardness value of 9.2 GPa. These results also show that thin films follow different phase formation pathways compared to HfNbTiVZr bulk alloys.

Iron Redistribution in Aluminum Thin Films

1993 ◽  
Vol 309 ◽  
Author(s):  
David L. Barr ◽  
G.J. Gualtieri ◽  
C.B. Case ◽  
M.A. Marcus ◽  
W.L. Brown
Keyword(s):  
Thin Films ◽  
Grain Boundary ◽  
Grain Growth ◽  
Deposition Temperature ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
Subsequent Annealing ◽  
Precipitate Formation ◽  
Substrate Interface ◽  
Depth Distributions

AbstractStrongly non uniform Fe depth distributions have been observed in AI(0.13 at% Fe) thin films deposited at temperatures of 350ºC and above. The concentration of Fe is uniform in depth at a deposition temperature of 300ºC but is increasingly enhanced toward the substrate interface at 450ºC. Subsequent annealing produces only a slight redistribution of Fe. The Fe is primarily present as precipitates smaller than 100 nm. A model of grain boundary diffusion of Fe and precipitate formation and grain growth is proposed to explain the observed behavior.

Properties of Ag Doped CdTe Thin Film Prepared by Stacked Elemental Layer (SEL) Method

2012 ◽  
Vol 488-489 ◽  
pp. 742-747
Author(s):  
Subramani Shanmugan ◽  
Devarajan Mutharasu ◽  
Hassan Zainuriah
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Roughness ◽  
Transition Metals ◽  
Grain Growth ◽  
Cubic Phase ◽  
Light Sources ◽  
Cdte Thin Film ◽  
Elemental Layer

Thin films of elements (Cd,Te,Ag) were layered as a stack (Te/Cd/Te/Ag/Cd) for doping process with different Ag and Cd thickness by SEL method. The XRD results were depicted the presence of Cubic phase CdTe with (111) orientation along with Ag2Te, CdAgTe, AgTe phases. The peaks related to Ag atom at higher concentration evinced the presence of non-reacted Ag atoms on the surface with higher Ag concentration. The observed results showed the growth of CdTe crystals in (111) orientation with high Ag concentration. The AFM results of the annealed stack were clearly indicated the influence of Ag concentration in grain growth as well as surface roughness. Photo-resistivity studies of the annealed stacks also revealed the effect of Ag concentration in reducing the resistance with difference light sources. The observed results suggested that the SEL method could be used for effective doping of transition metals to achieve desired properties.

Self-Limited to Parabolic Grain Growth Kinetics in Metal Oxide Thin Films

2012 ◽  
Vol 715-716 ◽  
pp. 333-333
Author(s):  
Jennifer L.M. Rupp ◽  
Barbara Scherrer ◽  
Julia Martynczuk ◽  
Ludwig J. Gauckler
Keyword(s):  
Thin Films ◽  
Metal Oxide ◽  
Grain Growth ◽  
Growth Kinetics ◽  
Deposition Temperature ◽  
Crystalline State ◽  
Oxide Thin Film ◽  
Processing Route ◽  
Interface Diffusion ◽  
Grain Growth Kinetics

Distinctive microstructure engineering of amorphous to nanocrystalline electroceramic thin films is of high relevance for integration in low to high temperature operating MEMS-devices. Up to now, kinetic rules of nucleation, crystallization and grain growth of precipitation-based ceramic thin films are unknown. In this study, general rules for the crystallization and grain growth kinetics of a pure single-phase metal oxide thin film with only one kind of cation, i.e. ceria, made by spray pyrolysis from a precursor with one single organic solvent is discussed [1,. The near-and long range disorder is studied via Raman, DSC investigation of crystallization enthalpy, XRD, SEM and TEM for amorphous to fully crystalline state. These 400 nm thick-thin films were dense, crack-free and amorphous directly after deposition on a sapphire substrate. Briefly, above deposition temperature crystallization sets in with respect to temperature and persists over a broad temperature range from 400 to 950°C. In this regime, biphasic amorphous-crystallien films exist and grain growth proceeds simultaneously to crystallization. Isothermal grain growth studies showed that after short dwell times of 10-20h stable microstructures established following self-limited grain growth law [. In this state, driving force for the crystallization is the reduction of free enthalpy for phase transformation and interface diffusion prevails. A transition to classical grain curvature-driven parabolic grain growth kinetics appeared once the material reached the fully crystalline state for average grain sizes larger than 140 nm and higher annealing temperatures. Volume diffusion was then activated in addition to the interface diffusion. It was found that once crystallized the material shows independent on processing route equal XRD density and microstrain, as well as Raman characteristics. However, dependent on processing conditions i.e. choice of organic and, according, deposition temperature of the film amorphous states vary and affect strongly crystallization and grain growth history for the biphasic films.

Sign in / Sign up

Export Citation Format

Share Document