scholarly journals Incorporation of Iron Cations Into Epitaxial Sapphire Thin Films by CO-Evaporation and Subsequent Thermal Annealing

1994 ◽  
Vol 341 ◽  
Author(s):  
Ning Yu ◽  
Harriet Kung ◽  
Michael Nastasi ◽  
DeQuan Li
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Thermal Annealing ◽  
Rutherford Backscattering Spectrometry ◽  
Ultra Violet ◽  
Cation Sublattice ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Simple Method ◽  
Subsequent Thermal Annealing

AbstractIron-doped sapphire thin films have been successfully epitaxially grown onto sapphire single crystal substrates by electron beam deposition and subsequent thermal annealing. Amorphous A12O3 thin films, about 280–390 nm thick, cation doped with iron have been deposited on [0001] oriented sapphire substrates. Iron doping with cation concentrations (a ratio of Fe content to total cation content) up to 5 at.% can be incorporated into the octahedral sites of Al-cation sublattice during the epitaxial regrowth process at 1000–1400 C, as determined by Rutherford Backscattering Spectrometry and ion channeling measurements. Cross-sectional Transmission Electron Microscopy shows the presence of two distinct regions in the annealed films. One exhibits the epitaxial relationship with the sapphire substrate and the second region has amorphous type of contrast. External optical transmittance measurements in the ultra violet and visible light range have exhibited the absorption associated with Fe3+. This study has demonstrated a simple method of incorporating dopants into single crystal sapphire, which has potential in the fabrications of thin film planar optical waveguiles.

Evolution of Epitaxial SixGei1-x Alloys on Si(100) During Thermal Annealing a-Ge/Au Bilayers Deposited on Si Substrate

1992 ◽  
Vol 280 ◽  
Author(s):  
Z. Ma ◽  
L. H. Allen
Keyword(s):  
Single Crystal ◽  
Thermal Annealing ◽  
Rutherford Backscattering Spectrometry ◽  
Solid Phase ◽  
Growth Dynamics ◽  
X Ray Diffraction ◽  
Si Substrate ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron

ABSTRACTSolid phase epitaxial (SPE) growth of SixGei1-x alloys on Si (100) was achieved by thermal annealing a-Ge/Au bilayers deposited on single crystal Si substrate in the temperature range of 280°C to 310°C. Growth dynamics was investigated using X-ray diffraction, Rutherford backscattering spectrometry, and cross-sectional transmission electron microscopy. Upon annealing, Ge atoms migrate along the grain boundaries of polycrystalline Au and the epitaxial growth initiates at localized triple points between two Au grains and Si substrate, simultaneously incorporating a small amount of Si dissolved in Au. The Au is gradually displaced into the top Ge layer. Individual single crystal SixGei1-x islands then grow laterally as well as vertically. Finally, the islands coalesce to form a uniform layer of epitaxial SixGe1-x alloy on the Si substrate. The amount of Si incorporated in the final epitaxial film was found to be dependent upon the annealing temperature.

Integration of NiSi SALICIDE for Deep Submicron CMOS Technologies

1998 ◽  
Vol 514 ◽  
Author(s):  
X. W. Lin ◽  
N. Ibrahim ◽  
L. Topete ◽  
D. Pramanik
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Sheet Resistance ◽  
Thermal Annealing ◽  
Cmos Technology ◽  
Deep Submicron ◽  
Thermal Budget ◽  
Si Substrates ◽  
Low Thermal Budget ◽  
Lower Resistivity

ABSTRACTA NiSi-based self-aligned silicidation (SALICIDE) process has been integrated into a 0.25 Ion CMOS technology. It involves rapid thermal annealing (RTA) of Ni thin films (300, Å thick) on Si substrates in the temperature range ≈400 - 700 °C. It was found that the NiSi sheet resistance (Rs) gradually decreases with decreasing linewidth. Parameters, such as RTA temperature, substrate dopant (As vs BF2) and structure (single crystal vs poly), were found to have little effects on Rs. NiSi forms a smoother interface with single crystalSi than with poly Si, and has a slightly lower resistivity. MOSFETs based on NiSi show comparable device characteristics to those obtained with Ti SALICIDE. Upon thermal annealing, NiSi remains stable at 450 °C for more than 39 hours. The same is true for 500 °C anneals up to 6 hours, except for NiSi narrow lines (<0.5 μm) on n+ poly Si substrates whose Rs is moderately increased after a 6 hr anneal. This work demonstrates that with an appropriate low-thermal budget backend process, NiSi SALICIDE can be a viable process for deep submicron ULSI technologies.

Growth of a-plane ZnO Thin Films on r-plane Sapphire by Plasma-assisted MBE

2005 ◽  
Vol 891 ◽  
Author(s):  
Junqing Q. Xie ◽  
J. W. Dong ◽  
A. Osinsky ◽  
P. P. Chow ◽  
Y. W. Heo ◽  
...  
Keyword(s):  
Thin Films ◽  
Lattice Mismatch ◽  
Defect Density ◽  
Zno Thin Films ◽  
Rf Plasma ◽  
Misfit Dislocations ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Small Lattice

ABSTRACTZnO thin films have been epitaxially grown on r-plane sapphire by RF-plasma-assisted molecular beam epitaxy. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies indicate that the epitaxial relationship between ZnO and r-plane sapphire is (1120)ZnO // (1102)sapphire and [0001]ZnO // [1101]sapphire. Atomic force microscopy measurements reveal islands extended along the sapphire [1101] direction. XRD omega rocking curves for the ZnO (1120) reflection measured either parallel or perpendicular to the island direction suggest the defect density anisotropy along these directions. Due to the small lattice mismatch along the ZnO [0001] direction, few misfit dislocations were observed at the ZnO/Al2O3 interface in the high-resolution cross-sectional TEM image with the zone axis along the ZnO [1100] direction.

TiSi2 Integrity within a Doped Silicide Process Step

1992 ◽  
Vol 279 ◽  
Author(s):  
G. M. Crean ◽  
P. D. Cole ◽  
J. Stoemenos
Keyword(s):  
Thin Films ◽  
Sheet Resistance ◽  
Silicon Substrate ◽  
Thermal Processing ◽  
Rutherford Backscattering Spectrometry ◽  
Cross Sectional ◽  
Process Step ◽  
Thermal Budget ◽  
Transmission Electron ◽  
Junction Formation

ABSTRACTDegradation of arsenic implanted titanium suicide (TiSi2) thin films as a result of thermal processing for shallow junction formation is investigated. Significant arsenic diffusion from the suicide overlayer into the silicon substrate has been detected by Rutherford Backscattering Spectrometry at drive-in temperatures > 1050°C. Cross-sectional transmission electron micrographs have shown the suicide film become increasingly non-uniform as the thermal budget increases, ultimately leading to discontinuities forming in the suicide film. This observed degradation of the titanium suicide film is also supported by sheet resistance measurements which show the film to degrade significantly above a threshold thermal budget

Epitaxial cerium oxide buffer layers and YBa2Cu3O7−δ thin films for microwave device applications

1999 ◽  
Vol 14 (6) ◽  
pp. 2385-2393 ◽  
Author(s):  
Sissel N. Jacobsen ◽  
Lynnette D. Madsen ◽  
Ulf Helmersson
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Rf Magnetron Sputtering ◽  
Sample Surface ◽  
Columnar Structure ◽  
Buffer Layers ◽  
Ex Situ ◽  
Epitaxial Relationship ◽  
Cross Sectional ◽  
Appreciable Change

CeO2 films with thicknesses ranging from 8.8 to 199 nm were grown on Al2O3 (1102) (R-cut) substrates by off-axis rf magnetron sputtering. X-ray diffraction showed an epitaxial relationship with the CeO2 (001) planes parallel to the Al2O3 (1102) planes for all film thicknesses. Atomic force microscopy (AFM) revealed a rough surface morphology consisting of crystallites with lateral dimensions of 10–90 nm. In the thinnest film, these crystallites were regularly shaped and uniformly distributed on the substrate, while they were rectangularly shaped and oriented mainly in two directions, orthogonal to each other, in the thicker films. The surface roughness of the films increased with increasing layer thickness. Characterization of the microstructure was done by cross-sectional transmission electron microscopy (XTEM) and showed a polycrystalline, highly oriented, columnar structure with a top layer terminated by (111)-facets. High-quality YBa2Cu3O7−δ (YBCO) thin films were deposited directly onto the CeO2 layers. XTEM, rather surprisingly, showed a smooth interface between the YBCO and CeO2 layer. Postdeposition ex situ annealing was carried out on two CeO2 films and evaluated by AFM. Upon annealing samples at 930 °C, a relatively smooth morphology without facets was obtained. Annealing films at 800 °C caused no appreciable change in surface morphology, whereas igniting a YBCO plasma during a similar anneal clearly altered the sample surface, giving facets that were rounded.

Fabrication of C54-TiSi2 Thin Films Using Cathodic Arc Deposition and Rapid Thermal Annealing

2007 ◽  
Vol 1052 ◽  
Author(s):  
Hui Xia ◽  
William R. Knudsen ◽  
Paul L. Bergstrom
Keyword(s):  
Thin Films ◽  
Phase Transformation ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Rutherford Backscattering Spectrometry ◽  
Substrate Bias ◽  
Cathodic Arc Deposition ◽  
The Impact ◽  
Cathodic Arc ◽  
Arc Deposition

AbstractDue to its low electrical resistivity and high thermal stability, C54-TiSi2 thin films can be used in some MEMS application, such as RF MEMS, to reduce RC delay and improve dynamic performance. In this paper, TiSi2 thin films have been prepared for the first time by using cathodic arc deposition to study the impact of energetic ion bombardment on the film microstructure and subsequent C49-C54 phase transformation during annealing. TiSi2 compound was used as the cathode and a substrate bias was varied to control kinetic energy of the ions during the film growth. Rutherford backscattering spectrometry and transmission electron microscopy were utilized to characterize the film composition and microstructure. The composition of the resultant TiSix thin films varies from x=2.4 to x=1.4 when the substrate bias was varied from floating to –200V. The as-deposited TiSix films are amorphous under no substrate heating and a phase separation at nano scale with inhomogeneous distribution of Ti and Si atoms was observed within the amorphous phase. Si atoms are seen to segregate on the boundary of Ti-rich domains and the domain size increased with the substrate bias. For a 90nm-thick TiSi2 film deposited on a SiO2/Si substrate, kinetics of the C49-C54 phase transformation was studied by measuring the change of film resistivity upon rapid thermal annealing. It was found that the C49-C54 phase transition temperature is higher (>900°C) for the arc-deposited TiSi2 thin films compared to evaporated and sputtered films and the activation energy for the transformation was calculated to be 6.1±0.2eV.

A Novel Process to Form Epitaxial Si Structures With Buried Silicide

1991 ◽  
Vol 235 ◽  
Author(s):  
YU. N. Erokhin ◽  
R. Grotzschel ◽  
S. R. Oktyabrski ◽  
S. Roorda ◽  
W. Sinke ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Annealing ◽  
Crystalline Silicon ◽  
Rutherford Backscattering Spectrometry ◽  
Amorphous Layer ◽  
Cross Sectional ◽  
X Ray ◽  
Metal Atoms ◽  
Transmission Electron ◽  
High Metal

ABSTRACTThe interaction during low temperature thermal annealing of metal atoms from a Ni film evaporated on top of Si structures with a buried amorphous layer formed by ion implantation has been investigated. Rutherford Backscattering Spectrometry (RBS)/channeling, cross-sectional transmission electron microscopy (XTEM) and X-ray microanalysis were used to determine structures and compositions. It is shown that the combination of such silicon properties as the increased rate of silicidation reaction for amorphous silicon with respect to the crystalline one in combination with high metal atom diffusivity leads to formation of buried epitaxial Ni silicide islands at the interface between the amorphous and the top crystalline silicon layers. During thermal annealing at temperatures as low as 350° C, these islands move through the a-Si layer leaving behind epitaxially recrystallized Si.

Extraction of Elastic Modulus and Hardness of the Soft Metallic Films on Hard Substrates by Nanoindentation

2007 ◽  
Vol 561-565 ◽  
pp. 2005-2008
Author(s):  
X.Y. Zhou ◽  
Hai Rong Wang ◽  
Zhuang De Jiang ◽  
Rui Xia Yu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Elastic Modulus ◽  
Contact Stiffness ◽  
Cross Sectional ◽  
Simple Method ◽  
Sem Image ◽  
Sputter Deposited ◽  
Film Substrate ◽  
Hard Substrates

A simple method to extract the intrinsic mechanical properties of the soft metallic thin films on hard substrates by nanoindenation is presented. Utilizing the geometry relationship of residual impressions obtained by the SEM image and the cross-sectional profile, the pile up error in elastic modulus determination of soft thin films by the Oliver and Pharr analysis is first corrected. Knowledge of the ‘true’ elastic modulus, the ‘true’ hardness of thin film is then extracted from the measured contact stiffness data for an elastically homogeneous film-substrate system. The present method is applied for a 504 nm Au thin film sputter deposited on the glass substrate and the results show that the ‘true’ elastic modulus and hardness of Au film are 80 GPa and 1.3 GPa, which are in agreement well with the literatures.

Interfacial Strain Reliefs in Epitaxial YBa2Cu3O7–δ Thin Films Grown on SrTiO3 Buffered MGO Substrates

1997 ◽  
Vol 505 ◽  
Author(s):  
Xingtian Cui ◽  
Q. Y Chen ◽  
Yongxiang Guo ◽  
W. K. Chu
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Rutherford Backscattering Spectrometry ◽  
Epitaxial Thin Films ◽  
Cross Sectional ◽  
Ybco Films ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Edge Dislocations

ABSTRACTHigh quality YBa2Cu3O7–δ, (YBCO) epitaxial thin films grown on MgO substrate with a strainrelieved SrTiO3 (STO) buffer layer have been investigated by Rutherford backscattering spectrometry (RBS), ion channeling and high resolution cross sectional transmission electron microscopy (XTEM). The in-situ growth of STO buffer layer along with the YBCO films was carried out by pulsed laser ablation. In this work, minimum yield of channeling measurements have shown that a very thin STO buffer layer is sufficient to grow highly crystalline YBCO thin films on MgO substrates. TEM studies showed that the STO layers were strain-relieved by an array of periodic edge dislocations. The YBCO films on STO buffer, as in those grown directly on an STO substrate, evolved from a strained layer to a largely dislocation free area.

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