Lattice Defects in SrRuO3 Thin Films and Their Contribution to film Resistivity

1999 ◽  
Vol 574 ◽  
Author(s):  
N. D. Zakharov ◽  
K. M. Satyalakshmi ◽  
G. Koren ◽  
D. Hesse
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Lattice Defects ◽  
Cubic Phase ◽  
Orthorhombic Structure ◽  
Film Resistivity ◽  
High Electrical Resistivity ◽  
Lattice Symmetry ◽  
Transmission Electron ◽  
Substrate Temperatures

AbstractLattice defects present in PLD-grown, epitaxial SrRuO3 thin films on (001) SrTiO3 substrates are analyzed by high resolution transmission electron microscopy (HRTEM). Before the preparation of TEM samples, the electrical resistivity of films grown at different substrate temperatures was determined. Films grown at 775 °C exhibited a low electrical resistivity of only 200 μΩcm. They were found to be of orthorhombic structure and contained only few lattice defects. Films grown at 700 °C showed a high electrical resistivity of 1400 μΩcm. They were of cubic lattice symmetry, while films grown at temperatures above 800 °C showed resistivities between 300 and 900 μΩcm. The latter films mainly consist of an orthorhombic-cubic phase mix and involve lattice defects of high density, such as twins and antiphase boundaries (APBs). These defects are mainly located in between the islands and obviously contribute to the high film resistivity observed. For example, the APBs contain an extra single SrO layer, which is certainly insulating. Moreover, Ru vacancies are present in these films.

Substrate temperature dependence of structure and resistivity of SrRuO3 thin films grown by pulsed laser deposition on (100) SrTiO3

1999 ◽  
Vol 14 (11) ◽  
pp. 4385-4394 ◽  
Author(s):  
N. D. Zakharov ◽  
K. M. Satyalakshmi ◽  
G. Koren ◽  
D. Hesse
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Cubic Phase ◽  
Orthorhombic Structure ◽  
Antiphase Boundaries ◽  
Transmission Electron ◽  
Different Temperatures

The resistivity of SrRuO3 thin films on (001) SrTiO3 substrates grown at different temperatures by pulsed laser deposition is correlated to the microstructure. Films grown at 775 °C are of an orthorhombic structure, contain very few defects, and exhibit a low resistivity of 150 μΩ cm. Films grown at other temperatures contain a cubic phase and show higher resistivities. The defects present in the films, particularly twins and antiphase boundaries, are analyzed by high-resolution transmission electron microscopy, and their origin, as well as influence on film resistivity, is discussed.

Epitaxial Growth of AlN Thin Films on Silicon and Sapphire by Pulsed Laser Deposition

1995 ◽  
Vol 395 ◽  
Author(s):  
R.D. Vispute ◽  
H. Wu ◽  
K. Jagannadham ◽  
J. Narayan
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Pulsed Laser Deposition ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Breakdown Field ◽  
Transmission Electron ◽  
Uv Visible ◽  
Relationship Of

ABSTRACTAIN thin films have been grown epitaxially on Si(111) and Al2O3(0001) substrates by pulsed laser deposition. These films were characterized by FTIR and UV-Visible, x-ray diffraction, high resolution transmission electron and scanning electron microscopy, and electrical resistivity. The films deposited on silicon and sapphire at 750-800°C and laser energy density of ∼ 2 to 3J/cm2 are epitaxial with an orientational relationship of AIN[0001]║ Si[111], AIN[2 110]║Si[011] and AlN[0001]║Al2O3[0001], AIN[1 2 1 0]║ Al2O3[0110] and AIN[1010] ║ Al2O3[2110]. The both AIN/Si and AIN/Al2O3 interfaces were found to be quite sharp without any indication of interfacial reactions. The absorption edge measured by UV-Visible spectroscopy for the epitaxial AIN film grown on sapphire was sharp and the band gap was found to be 6.1eV. The electrical resistivity of the films was about 5-6×l013Ω-cm with a breakdown field of 5×106V/cm. We also found that the films deposited at higher laser energy densities ≥10J/cm2 and lower temperatures ≤650°C were nitrogen deficient and containing free metallic aluminum which degrade the microstructural, electrical and optical properties of the AIN films

Structrual Characterization and Raman Scattering of Epitaxial Aluminum Nitride Thin Films on Si(111)

1992 ◽  
Vol 242 ◽  
Author(s):  
W. J. Meng ◽  
T. A. Perry ◽  
J. Heremans ◽  
Y. T. Cheng
Keyword(s):  
Thin Films ◽  
Aluminum Nitride ◽  
Raman Scattering ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reactive Sputter Deposition ◽  
Transmission Electron ◽  
Substrate Temperatures

ABSTRACTThin films of aluminum nitride were grown epitaxially on Si(111) by ultra-high-vacuum dc magnetron reactive sputter deposition. Epitaxy was achieved at substrate temperatures of 600° C or above. We report results of film characterization by x-ray diffraction, transmission electron microscopy, and Raman scattering.

CW Nd:YAG Laser Deposition of CdS Thin Films

1992 ◽  
Vol 281 ◽  
Author(s):  
X. W. Wang ◽  
D. J. Finnigan ◽  
R. Noble ◽  
P. Mattocks
Keyword(s):  
Thin Films ◽  
Nd:Yag Laser ◽  
Substrate Material ◽  
Laser Deposition ◽  
Cubic Phase ◽  
Physical Measurements ◽  
Transmission Electron ◽  
Cds Thin Films ◽  
Diffraction Patterns ◽  
Two Phases

ABSTRACTThere are two phases of CdS, wurtzite (hexagonal) and zincblende (cubic). To the best of our knowledge there is no report on the growth of large single crystal cubic CdS. Although there have been reports on the vapor deposition of cubic dominated CdS thin films, physical measurements were limited. Substrate material has been considered as the primary factor in attaining the cubic dominated CdS thin films. We report new results on CW Nd:YAG laser deposition of CdS thin films at various temperatures. X-ray diffraction patterns show that the films deposited at 200°C have a dominant cubic phase, those at 400°C being hexagonal. Optical transmission measurements reveal room temperature absorption edges of 515nm and 500nm for films deposited at 200°C and 400°C, respectively. Transmission electron microscopy further reveals differences in crystal structure of the two films. Raman spectra of the cubic film is similar to that of the hexagonal film.

Synthesis of (SIC)3N4 Films by Ion Implantation

1993 ◽  
Vol 316 ◽  
Author(s):  
C. Uslu ◽  
D. H. Lee ◽  
Y. Berta ◽  
B. Park ◽  
N. N. Thadhani ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Amorphous Layer ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Nitrogen Implantation ◽  
Transmission Electron ◽  
Position Sensitive ◽  
Nitrogen Ions ◽  
Substrate Temperatures ◽  
New Phase

ABSTRACTWe have investigated the synthesis of carbon-silicon-nitride compounds by ion implantation. In these experiments, 100 keV nitrogen ions were implanted into polycrystalline β-SiC (cubic phase) at various substrate temperatures and ion doses. These thin films were characterized in detail by x-ray diffraction with a position-sensitive detector, transmission electron microscopy with chemical analysis, and Rutherford backscattering spectroscopy. The as-implanted samples show a buried amorphous layer at a depth of 170 nm. The peak concentration of nitrogen saturates at approximately 45 at. % with doses above ~9.0×1017 N/cm2 at 860°C. These results suggest formation of a new phase by nitrogen implantation into β-SiC.

TEM of Pyrolytic Al2O3 and Ta-Al2O3 Thin Films on Silicon

1974 ◽  
Vol 32 ◽  
pp. 474-475
Author(s):  
R. M. Anderson
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Cross Sections ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Deposition Rates ◽  
Metal Insulator ◽  
Semiconductor Structures ◽  
High Electrical Resistivity ◽  
Amorphous Structures

Pyrolytically deposited Al2O3, thin films are employed as dielectrics in metal-insulator-semiconductor structures used for insulated-gate field-effect transistors. Ideally, very thin Al2O3 films should have smooth surfaces, uniform cross-sections and high electrical resistivity. These requirements are best met by amorphous Al2O3, film microstructures. Pyrolysis of amorphous Al2O3 films must be undertaken at temperatures lower than 700°C with a concomitant low deposition rate. The incorporation of Ta in the Al2O3 yields amorphous structures at deposition tempera tures of about 800-900°C with substantially higher deposition rates.

The structure and distribution of 90° domains in PbTiO3 ferroelectric thin films

1994 ◽  
Vol 52 ◽  
pp. 564-565
Author(s):  
S. K. Streiffer ◽  
S. Stemmer ◽  
W.-Y. Hsu ◽  
F. Ernst ◽  
R. Raj ◽  
...  
Keyword(s):  
Thin Films ◽  
Volume Fraction ◽  
Second Harmonic ◽  
Ferroelectric Thin Films ◽  
Cubic Phase ◽  
Tetragonal Modification ◽  
Intrinsic Factors ◽  
Transmission Electron ◽  
Saturation Polarization ◽  
A Domains

Many properties of perovskite-derived, tetragonal, ferroelectric thin films, such as saturation polarization and coefficient of second harmonic generation, have proven to be a strong function of the volume fraction of material oriented with its c-axis approximately perpendicular to the plane of the substrate, the so-called a-domains. Films are typically deposited above their Curie temperature, and a-domains form during cooling after growth in order to relieve strains generated by the transformation of the material from the high-temperature cubic phase to the ferroelectric, tetragonal modification. Models based on free-energy considerations of this twinning transformation under the constraints imposed by a rigid substrate have been proposed which predict a-domain widths and volume fractions as a function of e.g., film thickness and epitaxial and thermal expansion mismatch with the substrate.We have used transmission electron microscopy to examine the intrinsic factors influencing the size and distribution of a-domains in epitaxial PbTiO3 ferroelectric thin films grown by laser ablation.

Early stages of the growth of BaTiO3 thin films studied by Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 706-707
Author(s):  
M. Grant Norton ◽  
Gerald R. English ◽  
Christopher Scarfone ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Room Temperature ◽  
High Temperature Superconductors ◽  
Pulsed Laser ◽  
Target Material ◽  
Pulsed Laser Ablation ◽  
Cubic Phase ◽  
Transmission Electron ◽  
Tetragonal Form

Barium titanate (BaTiO3) may be used in a number of thin-film applications in electronic and optoelectronic devices. For these devices the formation of epitactic films of the correct stoichiometry and phase is essential. In particular, the tetragonal form of BaTiO3, which is stable at room temperature, exhibits ferro-, pyro- and piezoelectric properties. It is desirable to form films of the tetragonal phase directly and thus to avoid formation of either amorphous or polycrystalline material or to form material of the non-ferroelectric cubic phase. Recently two techniques, pulsed-laser ablation and reactive evaporation, have been used to form BaTiO3 thin-films. In the present study BaTiO3 thin-films have been formed using the pulsed-laser ablation technique. Pulsed-laser ablation is now widely used to produce thin-films of the high temperature superconductors and has many advantages over other techniques, in particular the formation of films which maintain the stoichiometry of the target material and by controlling the processing conditions the formation of films having defined crystalline phases.

Estimation of Magnetic Energy Distribution in Co84Cr16Ta4 Magnetic Thin Films from EFTEM

2007 ◽  
Vol 1026 ◽  
Author(s):  
Jafar F. Al-Sharab ◽  
James E Wittig ◽  
James Bentley ◽  
Neal Evans ◽  
Gerardo Bertero ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Energy ◽  
Boundary Segregation ◽  
Magnetic Thin Films ◽  
Size Distributions ◽  
Transmission Electron ◽  
Magnetic Decoupling ◽  
Grain Size Distributions ◽  
Substrate Temperatures ◽  
Seed Layers

AbstractMagnetic thin films of Co80Cr16Ta4 were sputtered onto identical CrMo seed-layers at −200 V bias and 3 different substrate temperatures (150, 200, and 250°C). Energy-filtered transmission electron microscopy (EFTEM) was performed to analyze Cr levels at the grain boundaries as well as inside the grains. These quantitative Cr measurements were used to estimate the local values of magnetocrystalline anisotropy (Ku) and, together with grain size distributions, calculate the product of Ku and the grain volume (KuV), a quantity which is a measure of thermal stability. The results show that the coercivity as well as the percentage of stable grains increased with increasing substrate temperature. The increase in the number of stable grains is produced by the enhancement in the Ku value from Cr depletion of the grain interiors and the magnetic decoupling between the grains from Cr grain boundary segregation.

Cu and Dilute Binary Cu(Ti), Cu(Sn) and Cu(Al) Thin Films: Texture, Grain Growth and Resistivity

2002 ◽  
Vol 721 ◽  
Author(s):  
A. Gungor ◽  
K. Barmak ◽  
A. D. Rollett ◽  
C. Cabral ◽  
J. M. E. Harper
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Electrical Resistivity ◽  
Fiber Texture ◽  
Al Alloy ◽  
Alloy Films ◽  
Transmission Electron ◽  
Pure Cu

AbstractAnnealing Cu and dilute Cu(Ti), Cu(Sn) and Cu(Al) alloy films resulted in the strengthening of film texture, with the strongest <111> fiber texture being found for Cu(Ti). Annealing also resulted in a decrease of electrical resistivity and the growth of grains, with the largest grain size and lowest resistivity being seen for pure Cu itself. Among the alloy films, the lowest resistivity was found for Cu(Ti) and the largest grain size for Cu(Al). Electron beam evaporated films with compositions in the range of 2.0-3.0 at% and thicknesses in the range of 420-540 nm were annealed at 400°C for 5 hours. Four point probe resistance measurement, xray diffraction and transmission electron microscopy were used to follow the changes in film resistivity, texture and grain size.

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