Epitaxial YSi2−x and ErSi2−x Thin Films on (111) Silicon

1992 ◽  
Vol 263 ◽  
Author(s):  
T.L. Lee ◽  
W.D. Su ◽  
L.J. Chen
Keyword(s):  
Thin Films ◽  
Solid Phase ◽  
Metal Thin Films ◽  
Step Structure ◽  
Displacement Vectors ◽  
Transmission Electron ◽  
Vacancy Ordering ◽  
Deposited Metal ◽  
Long Time ◽  
Diffraction Patterns

ABSTRACTEpitaxial RSi2−x (R = Y and Er) has been grown on (111)Si by solid phase epitaxy in ultrahigh vacuum deposited metal thin films on silicon. The evolution of vacancy ordering and defect structure in epitaxial YSi2−x. and ErS2−x thin films on (111)Si have been studied by both conventional and high resolution transmission electron microscopy.Superlattice spots located at ⅓{2110} in [0001]RS2−x, diffraction patterns are attributed to the formation of ordered vacancy structure in the Si sublattice planes. The splitting of extra diffraction spots is correlated to the formation of an out-of-step structure. Streaking of the split diffraction spots in the diffraction pattern is attributed to the presence of an out-of-step structure with a range of M values. The M was found to settle down to a fixed value after high temperature and/or long time annealing.Planar defects in RSi2™x films were analyzed to be stacking faults on {1010} planes with ⅙<1213> displacement vectors. Computer simulation was carried out to model the atomic structure of stacking fault in YS2−x-. thin films. The simulated images are seen to match rather well with experimental images taken under two different values of defocus.

Epitaxial Growth of Rare Earth Silicides on (111)Si

1993 ◽  
Vol 312 ◽  
Author(s):  
T. L. Lee ◽  
W. D. Sue ◽  
J. H. Lin ◽  
C. H. Luo ◽  
L. J. Chen
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Diffraction Pattern ◽  
Solid Phase ◽  
Stacking Faults ◽  
Metal Thin Films ◽  
Step Structure ◽  
Displacement Vectors ◽  
Transmission Electron ◽  
Long Time

AbstractEpitaxial YSi2-x, TbSi2-x, and ErSi2-x. have been grown on (111)Si by solid phase epitaxy in ultrahigh vacuum deposited rare earth (RE) metal thin films on silicon. The evolution of vacancy ordering and defect structure in epitaxial RE silicide thin films on (111)Si have been studied by both conventional and high resolution transmission electron microscopy.Additional superlattice spots located at 1/3 <2110> in the diffraction pattern of RESi2-x, are attributed to the formation of ordered vacancy in the Si sublattice planes. The splitting of extra diffraction spots is correlated to the formation of an out-of--step structure. Streakings of the split diffraction spots in the diffraction pattern are attributed to the presence of an out-of-step structure with a range of M values. For YSi2-x and ErSi2-x, the M was found to settle down to a constant value after high temperature and/or long time annealing. For TbSi2-x, M is equal to 5 throughout the annealing.Planar defects in RESi2-x films were analyzed to be stacking faults on {1010} planes with 1/6<1213> displacement vectors. The size and density of stacking faults were found to increase and decrease, respectively, with annealing temperature and/or annealing time.

Transmission Electron Microscopy studies of the vacancy ordering in YSI2-X thin films

1991 ◽  
Vol 49 ◽  
pp. 562-563
Author(s):  
F.-R. Chen ◽  
T. L. Lee ◽  
L. J. Chen
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thin Films ◽  
Diffraction Pattern ◽  
Annealing Temperature ◽  
Lattice Mismatch ◽  
Si Substrate ◽  
Metal Thin Films ◽  
Transmission Electron ◽  
Vacancy Ordering

YSi2-x thin films were grown by depositing the yttrium metal thin films on (111)Si substrate followed by a rapid thermal annealing (RTA) at 450 to 1100°C. The x value of the YSi2-x films ranges from 0 to 0.3. The (0001) plane of the YSi2-x films have an ideal zero lattice mismatch relative to (111)Si surface lattice. The YSi2 has the hexagonal AlB2 crystal structure. The orientation relationship with Si was determined from the diffraction pattern shown in figure 1(a) to be and . The diffraction pattern in figure 1(a) was taken from a specimen annealed at 500°C for 15 second. As the annealing temperature was increased to 600°C, superlattice diffraction spots appear at position as seen in figure 1(b) which may be due to vacancy ordering in the YSi2-x films. The ordered vacancies in YSi2-x form a mesh in Si plane suggested by a LEED experiment.

Kinetics of Vacancy Ordering in YSi2−x Thin Film on Silicon

1991 ◽  
Vol 230 ◽  
Author(s):  
T. L. Lee ◽  
L. J. Chen ◽  
F. R. Chen
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Stacking Faults ◽  
Step Structure ◽  
Transmission Electron ◽  
Vacancy Ordering ◽  
Kinetics Of

AbstractHigh resolution and conventional transmission electron microscopy have been applied to study the interfacial reaction of yttrium thin films on Si. Epitaxial Ysi2−x film was grown on (111)Si by rapid thermal annealing at 500–1000 °C. The orientation relationship between yttrium silicide and (111)Si was determined to be [0001]Ysi2−x//[111]Si and (1010)Ysi2−x//(112)Si. The vacancies in the Ysi2−x film were found to be ordered in the Si sublattice plane and form an out-of-step structure. The range of M values of the out-of-step structure was found to narrow with annealing temperature and time. Defects along specific crystallographic directions were observed and analyzed to be intrinsic stacking faults.

Characterization of pulsed laser deposited MoS2 by transmission electron microscopy

1993 ◽  
Vol 8 (11) ◽  
pp. 2933-2941 ◽  
Author(s):  
S.D. Walek ◽  
M.S. Donley ◽  
J.S. Zabinski ◽  
V.J. Dyhouse
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Solid Phase ◽  
Analytical Electron Microscopy ◽  
Pulsed Laser ◽  
Cross Sectional ◽  
Aerospace Applications ◽  
Transmission Electron ◽  
Novel Method

Molybdenum disulfide is a technologically important solid phase lubricant for vacuum and aerospace applications. Pulsed laser deposition of MoS2 is a novel method for producing fully dense, stoichiometric thin films and is a promising technique for controlling the crystallographic orientation of the films. Transmission electron microscopy (TEM) of self-supporting thin films and cross-sectional TEM samples was used to study the crystallography and microstructure of pulsed laser deposited films of MoS2. Films deposited at room temperature were found to be amorphous. Films deposited at 300 °C were nanocrystalline and had the basal planes oriented predominately parallel to the substrate within the first 12–15 nm of the substrate with an abrupt upturn into a perpendicular (edge) orientation farther from the substrate. Spherically shaped particles incorporated in the films from the PLD process were found to be single crystalline, randomly oriented, and less than about 0.1 μm in diameter. A few of these particles, observed in cross section, had flattened bottoms, indicating that they were molten when they arrived at the surface of the growing film. Analytical electron microscopy (AEM) was used to study the chemistry of the films. The x-ray microanalysis results showed that the films have the stoichiometry of cleaved single crystal MoS2 standards.

(111)p microtwinning in SrRuO3 thin films on (001)p LaAlO3

2009 ◽  
Vol 65 (6) ◽  
pp. 694-698 ◽  
Author(s):  
Y. Han ◽  
I. M. Reaney ◽  
D. S. Tinberg ◽  
S. Trolier-McKinstry
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Orientation Relationship ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Zone Axis ◽  
Laser Deposition ◽  
Transmission Electron ◽  
Diffraction Patterns

SrRuO3 (SRO) thin films grown on (001)p (p = pseudocubic) oriented LaAlO3 (LAO) by pulsed laser deposition have been characterized using transmission electron microscopy. Observations along the 〈100〉p directions suggests that although the SRO layer maintains a pseudocube-to-pseudocube orientation relationship with the underlying LAO substrate, it has a ferroelastic domain structure associated with a transformation on cooling to room temperature to an orthorhombic Pbnm phase (a − a − c + Glazer tilt system). In addition, extra diffraction spots located at ±1/6(ooo)p and ±1/3(ooo)p (where `o' indicates an index with an odd number) positions were obtained in 〈110〉p zone-axis diffraction patterns. These were attributed to the existence of high-density twins on {111}p pseudocubic planes within the SrRuO3 films rather than to more conventional mechanisms for the generation of superstructure reflections.

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.

Platelets, dislocation loops and voidites in diamond

1986 ◽  
Vol 407 (1833) ◽  
pp. 239-258 ◽  
Keyword(s):  
Room Temperature ◽  
Solid Phase ◽  
Prismatic Slip ◽  
Dislocation Loops ◽  
High Pressure And Temperature ◽  
Burgers Vector ◽  
Transmission Electron ◽  
Microscope Images ◽  
Diffraction Patterns ◽  
Small Clusters

A type IaB diamond specimen containing partially decomposed platelets, dislocation loops and voidites has been investigated by transmission electron microscopy. The dislocation loops were found to be prismatic and interstitial in nature, some with Burgers vector ½ a <110> previously reported, but most with Burgers vector a <001>. Burgers vector analysis of the bounding dislocation of partially decomposed platelets shows that the a <001> loops are formed by transformation of the platelets, by nucleation and climb of a <00(1— f )> dislocation, combining with the a <00 f > dislocation bounding the platelet. The climb mechanism is driven by the need to generate vacancies for the decomposition of the platelets and to accommodate the nitrogen either in small clusters in solution in the lattice or in voidites. Glide dislocations interacting with the platelets are likely to act as nucleating centres for the climb process. The ½ a <110> dislocation loops are considered to be formed by dissociation of the a <001> loops, promoted by interaction with glide dislocations and involving prismatic slip and conservative climb. Voidites are assumed to originate as bubbles of fluid nitrogen formed at high pressure and temperature as a result of decomposition of the platelets; at room temperature they may be liquid or solid depending on the pressure, which cannot be estimated accurately. Electron diffraction patterns and microscope images of voidites prove that many consist of a solid phase at 300 K. It is suggested that the diamond has been subjected to a drop in pressure at high temperature, causing platelet decomposition and the generation of voidites, that may occur during ejection of the diamond to the earth’s surface.

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