Plan-view TEM Observations Research Articles

Plan-view TEM observation of a single-domain κ-Ga2O3 thin film grown on ε-GaFeO3 substrate using GaCl3 precursor by mist chemical vapor deposition

We demonstrated the growth of a single-domain κ-Ga2O3 thin film on ε-GaFeO3 by using an organic-free compound as a precursor for mist chemical vapor deposition. X-ray diffraction analysis revealed that an 86 nm thick κ-Ga2O3 thin film was grown almost coherently with slight lattice relaxation. The surface morphology of the κ-Ga2O3 thin film exhibited a step-terrace structure without island growth. Furthermore, plan-view TEM observations revealed that the κ-Ga2O3 thin film grown on ε-GaFeO3 had a single domain, whereas the previously reported κ-Ga2O3 thin film grown on AlN template had a domain structure.

Influence of Sputtering Conditions for Co/Pd Multilayer on its Magnetic Properties and Crystalline Microstructure

The effects of substrate temperatures during deposition and N2 gas addition to Ar sputtering gas on the magnetic properties and crystalline microstructure of Co/Pd multilayered films were investigated. The Co/Pd multilayered film deposited at a substrate temperature of 230°C with Ar containing N2 of 0.06 mTorr exhibited weaker intergranular exchange coupling than that deposited at room temperature without N2 addition. Plan-view TEM observation revealed that the crystal grains in the Co/Pd multilayered film, which was subjected to the heating process with N2 additive gas, were physically isolated by vacant grain boundaries, resulting in the decrease in intergranular exchange coupling.

Three Dimensional Characterization of a Specific Site by an FIB Micro-Sampling Technique

We have developed an FIB micro-sampling technique to prepare both plan view and cross-sectional TEM specimens from a specific site.The instruments that were used in this study are the Hitachi FB-2000A FIB system equipped a with micromanipulator unit and an HF-2200 cold field emission 200kV analytical TEM equipped with a scanning attachment allowing both STEM and SEM imaging.Figure 1 shows a procedure to prepare a micro-sample for either plan view or cross-sectional TEM observation of the specific site. First, the micro-sample for plan view TEM observation is trench milled by using an FIB(Figure 1a). Second, a tip of a micromanipulator W-probe is bonded to the micro-sample with the FIB assisted metal deposition. Then, the micro-sample is lifted out and transferred onto a micro-sample carrier(Figure 1b).

Stacking faults and their effect on magnetocrystalline anisotropy in Co and Co-alloy thin films

Stacking faults in (101~0) unicrystal Co and Co-alloy thin films have been analyzed by the electron diffraction technique. As predicted no diffraction contrast of stacking faults could be observed when the beam is parallel to the [101~0] direction. However, both by plan-view TEM observation and electron diffraction along the [112~0] direction reveal that the stacking fault density in biased pore Co (101~0) Bin films is much lower than that in unbiased ones. The addition of Cr in Co films significantly reduces stacking fault density whereas the addition of 8 at% Pt leads to a considerable increase in stacking fault density. Our results show that stacking faults in Co thin films significantly, and negatively, affect the anisotropy energy density and its temperature dependence.

Microstructural studies on YBCO film bicrystals with large single facetgrain boundaries grown by liquid phase epitaxy

In order to understand the intrinsic dependence of intergranularJc on the misorientation angle, a large, single-faceted grain boundary (GB)that is atomically smooth is necessary. Growth of YBCO film on MgO bicrystalsubstrates by liquid phase epitaxy (LPE) was applied to obtain largesingle-faceted GBs. Plan-view and cross sectional TEM observations confirmedthat the GBs are straight and a single facet with 10-30 µm dimension can beeasily found. High-resolution electron microscopic studies on these GBs showedthat GBs with misorientation angles of 4°, 8°, 12°,16° and 45° are single facets at the atomic scale, but 24°and 36° GBs are faceted at a scale, of a few nanometres. Shearstructures at stacking faults observed at asymmetric low-angle GB may resultin a Cu-rich GBs, so the stacking fault becomes insulting and is a strongbarrier for current flow. A possible relationship between the dependence ofJc on misorientation angles and microstructures are discussed for LPEbicrystals.

Plan-view and cross-sectional TEM observations of interfacial reactions and fractal formation in a-Ge/Au films

Interfacial reactions and fractal formation in amorphous Ge (a-Ge)/Au films have been studied by plan-view and cross-sectional transmission electron microscopy observations. The difference between the Ge crystallization temperatures of a-Ge/polycrystalline and a-Ge/single crystal Au films was found to be about 120°C. The fractal dimension of the Ge crystallites in a-Ge/ polycrystalline Au films was proportional to the Au grain size. The grain boundaries of the polycrystalline Au films and the surface of single crystal Au films were found to be the initial nucleation sites of Ge. In situ high-resolution electron microscopy observations showed successive nucleation of Ge at Au grain boundaries near fractal tips. The crystallization process was noted to be diffusioncontrolled and a random successive nucleation and growth mechanism is proposed to explain fractal formation. The large difference in the Ge crystallization temperatures of a-Ge/polycrystalline and a-Ge/single crystal Au films, and the morphology change of Ge fractals with Au grain size, imply that the microstructure of the metal film plays an important role in metal-mediated crystallization.

Plan-view and cross-sectional TEM observations of interfacial reactions and fractal formation in a-Ge/Au films

Plan-view and cross-sectional TEM observations of interfacial reactions and fractal formation in a-Ge/Au films

材料破壊への微視的アプローチ 亀裂および亀裂周辺の欠陥構造の電顕平面観察

材料破壊への微視的アプローチ 亀裂および亀裂周辺の欠陥構造の電顕平面観察

Phosphorus and boron doping effects on solid phase recrystallization of polycrystalline silicon films amorphized by germanium ion implantation

Fig. 1 shows the density of grains as a function of annealing time for the undoped, P-doped and Bdoped films that were subjected to Ge + with a dose of 1 x 1015cm -2 and annealed at 600°C. The density of grains was obtained by directly counting the number of grains produced in the amorphized films after annealing through plan-view TEM observation. It is shown that the number of grains was very small at the beginning of the annealing step, but after a certain incubation time, which is the time for nuclei to grow to the critical size, the number of grains increased rapidly. It was found from this figure that the initial generation of nuclei for the doped films is faster than that for the undoped films. This is presumed to be due to the stress effects induced by a mismatch of atomic size between the implanated atoms and Si atoms [5]. Fig. 2 shows the nucleation rate as a function of reciprocal annealing temperature for the same films as shown in Fig. 1. The nucleation rates of these films were estimated from the slope of the line, as shown in Fig. 1. As can be seen from this figure, it was found that the nucleation rate was strongly dependent on the kind of doping, with B doping increasing the nucleation rate and P doping decreasing it. This is presumed to be due to the increase in the local stress for the B-doped films and the increase in the implantation-induced damage for the P-doped films [6].

Can recoil distribution models account for end-of-range damage?

A quantitative evaluation of two existing models for end-of-range damage in Ge + implanted silicon is presented. The models propose that the amount of end-of-range damage is related to either (1) the number of ions or (2) the number of recoiling Si atoms that come to rest beyond the amorphous/crystalline (α/c) interface. TRIM (Monte Carlo) simulations of the implants studied were used to obtain the predictions of each model. These predictions were compared to experimental results obtained from implants at 30, 100 and 150 keV and doses of 5 × 10 14, 1 × 10 15 and 2 × 10 15. Plan view and cross-sectional TEM observations were used to determine the concentration of atoms bound by the end-of-range dislocation loops and the location of the α/c interface. Increasing the energy or dose resulted in significant increases in the amount of end-of-range damage. Neither model was able to consistently predict these trends at the lower doses and energies where ion beam induced epitaxial crystallization was suppressed. However, the recoil model was found to be superior overall to the ion model when compared to data from a wider range of implant conditions.

Cross-section TEM observations of amorphous nickel-titanium thin films formed by solid state reaction

There have been conflicting results concerning solid state amorphizing reactions (SSAR) in thin films consisting of alternating multiple layers of nickel and titanium. Clemens first reported evidence for SSAR in Ni-Ti using X-ray diffraction, Auger depth-profiling, and electrical conductivity measurements. The thickness of the Ni and Ti layers was 200 close-packed atom planes each in those samples in which SSAR was observed, although the reaction did not go to completion. Meng, et al. made plan-view TEM observations of films consisting of 10nm layers of Ni and Ti (about 50 atom planes) which had been vacuum- annealed for five hours at 250°C and 300°C. They observed that an intermetallic compound had formed as a result of the anneal, rather than amorphous material. The present study was initiated to explore the apparent conflict and to examine the kinetics of the SSAR if it occurred.

Successive tem observation of defects in Si-implanted GaAs

A novel technique for preparing specimens for successive plan-view TEM observations of defects at various depths is developed. It is found with this technique that in Si +-implanted GaAs defect-bands are composed with dislocation tangles, pinnings, stacking faults and dislocation loops.