TY - JOUR
AU - Hwang, James C., M.
AB - Abstract The origin of a marked difference in a dielectric constant, κ, observed between two types of strontium titanium oxide (STO) films sputter-deposited on platinum layers was investigated using a transmission electron microscopy method. The first type of STO films having a low κ value initially grew as an amorphous phase, followed by the formation of a randomly oriented polycrystalline phase. The second type with a high κ, on the other hand, not only grew as a crystalline phase throughout the entire film thickness, but also exhibited a strong [111] fiber texture. The observed difference in κ between these two types of STO films can thus be explained in terms of the degree of film crystallinity and texture. transmission electron microscopy, film texture, computer simulation of textured electron diffraction patterns Introduction A strontium titanium oxide, SrTiO3 (STO), known as strontium titanate, is a viable dielectric material that can be used as a high-voltage capacitor for memory devices and acoustic microwave resonators. It also serves as an excellent substrate for the epitaxial growth of high-temperature superconductors and many oxide-based thin films. For example, it was recently demonstrated [1] that the successful fabrication of highly textured STO films as a buffer layer was an important step toward the realization of large-area high Tc superconductor tapes. Most recently, using a sputtering technique, we have also successfully grown highly textured STO films with a high dielectric constant, κ, on top of platinum films. In this article, we will report two types of STO films having high and low dielectric constants using transmission electron microscopy (TEM). The nature and degree of film texture in STO films were also studied using an electron diffraction method. It will be shown that the observed difference in a dielectric constant between two types of STO films can be explained in terms of the film crystallinity and texture. A novel computer simulation technique was also applied to determine the degree of texturing in these films quantitatively. Experimental Each specimen is patterned with two types of layer configurations, I and II (see Fig. 1). Configuration I shown in Fig. 1a is basically identical to that of Fig. 1b except that the latter structure contains an additional top electrode consisting of platinum (Pt) and titanium nitride (TiN) layers. In these geometries, two types of STO films were grown by radio-frequency magnetron sputtering on top of a Pt layer, which was also sputter-deposited on thermal silicon oxide (SiO2)-covered {001} silicon substrates. Type A film was deposited on the 350°C substrates and had a low κ value of ∼100. Type B, on the other hand, was deposited on the 500°C substrates and had a high κ value of ∼200. Table 1 lists the nominal thickness value of each layer in the descending order from the top side. Table 1. Nominal layer thicknesses for Type A and B specimens . Thickness (µm) . Type of layer . Type A . Type B . Pt NP 0.2 TiN NP 0.01 STO 0.75–0.85 0.6–0.9 Pt 0.2 0.2 TiN 0.016 0.01 SiO2 0.43 0.2 {001} Si ∼520 ∼520 . Thickness (µm) . Type of layer . Type A . Type B . Pt NP 0.2 TiN NP 0.01 STO 0.75–0.85 0.6–0.9 Pt 0.2 0.2 TiN 0.016 0.01 SiO2 0.43 0.2 {001} Si ∼520 ∼520 NP, not present. Open in new tab Table 1. Nominal layer thicknesses for Type A and B specimens . Thickness (µm) . Type of layer . Type A . Type B . Pt NP 0.2 TiN NP 0.01 STO 0.75–0.85 0.6–0.9 Pt 0.2 0.2 TiN 0.016 0.01 SiO2 0.43 0.2 {001} Si ∼520 ∼520 . Thickness (µm) . Type of layer . Type A . Type B . Pt NP 0.2 TiN NP 0.01 STO 0.75–0.85 0.6–0.9 Pt 0.2 0.2 TiN 0.016 0.01 SiO2 0.43 0.2 {001} Si ∼520 ∼520 NP, not present. Open in new tab Fig. 1. Open in new tabDownload slide Two specimen configurations (I and II) of a layer structure involving a strontium titanate (STO) film used in this study. Fig. 1. Open in new tabDownload slide Two specimen configurations (I and II) of a layer structure involving a strontium titanate (STO) film used in this study. In the present TEM analysis, both cross-section and plan-view samples were prepared. The cross-section TEM (XTEM) samples were made by first sandwiching two identical samples face to face with epoxy glue. The sandwiched cross-section face was mechanically polished down to the thickness of ∼50 μm and then dimpled in the center region. The dimpled sample was finally thinned to the perforation using a Fischione's Model 1010 low-angle ion milling machine. During the course of this conventional TEM preparation, stressing due to mechanical polishing was thought to have caused layer delamination in some samples. To avoid such stress-related damage, a focused ion beam (FIB) machine was also used to prepare some cross-section samples. Plan-view samples were prepared by polishing from the substrate (silicon) side. This polishing utilizes a standard three-step method involving mechanical polishing, dimpling and final ion milling. It can be easily understood from Fig. 1a that this one-side polishing technique allows one to obtain a transparent specimen of only the uppermost layer, i.e. an STO layer. Here, only the specimen having the Configuration I was used for this specimen preparation. To study the effect of the Pt electrode layer on the structure of the subsequently deposited STO layer, we made a plan-view sample of the Pt film alone. To isolate the Pt film, a piece of the whole sample was soaked in a hydrofluoric acid solution, which dissolved the STO and SiO2, and TiN layers preferentially. The Pt film was then floated off in the solution and was finally scooped on a 3-mm oyster-type copper grid for subsequent TEM examinations. In addition to conventional bright-field (BF) and dark-field (DF) imaging, an electron diffraction technique was employed to plan-view samples of STO films for a fiber texture analysis. Although a texture study is generally done using X-ray diffraction, it can also be performed by electron diffraction in the transmission electron microscope, in which a textured film is systematically tilted over a wide range of angles available on a double-tilt specimen holder. Through the course of tilting, continuous diffraction rings characteristic of fine polycrystalline grains undergo a systematic splitting and arcing. The way that polycrystalline diffraction rings split and/or arc depends strongly on the type/degree of film texture, tilt angle and crystal structure. We have recently succeeded in simulating electron diffraction patterns with fiber texture. Therefore, a simulated diffraction pattern will be used for determining and predicting the type and degree of texture present in STO films quantitatively. TEM was conducted using a JEOL 2000FX microscope operated at an accelerating voltage of 200 kV. An FEI's DB235 dual-beam FIB system equipped with an Omniprobe's internal plucker was used for preparing some cross-section TEM samples. Results and discussion Two types of STO specimens were studied here. The dielectric constant of the specimens was determined experimentally; Type A specimen had a low κ dielectric constant (∼100), whereas Type B specimen had a high κ (∼200). Both plan-view and cross-section TEM specimens were prepared to determine the origin of the difference in κ between two types of STO samples. Type A sample Figure 2 is XTEM micrographs showing the face-to-face sandwiched Type A samples, where the epoxy glue is seen to hold two cross-sections together. The sequence of each identified layer seen in Fig. 2a is consistent with the diagram illustrated in Fig. 1; the upper cross-section represents the Configuration II, whereas the lower does the Configuration I. Figure 2b is the corresponding DF image. The presence of a columnar structure in the STO layer is apparent. In both sides of the sandwich, however, a wide crack is seen to be present between the Pt and STO layers. Fig. 2. Open in new tabDownload slide (a) A BF image showing the cross-sectional view of the face-to-face sandwiched Sample A and (b) the corresponding DF image. Fig. 2. Open in new tabDownload slide (a) A BF image showing the cross-sectional view of the face-to-face sandwiched Sample A and (b) the corresponding DF image. A careful examination of the STO layer revealed that the initial layer of the STO grown on top of the Pt layer was amorphous (a-STO) but switched to a crystalline phase (c-STO) with increasing film thickness (see Fig. 3). The thickness of the a-STO was found to vary from 0.11 to 0.16 µm and that of the c-STO ranged from 0.64 to 0.69 µm, while the total thickness of the STO was ∼0.8 µm. In addition, both Pt and TiN layers in the top electrode exhibit a columnar structure. Similarly, the bottom electrode layers of Pt and TiN grown on top of a thick (∼0.43 µm) SiO2 also showed a columnar structure. Fig. 3. Open in new tabDownload slide A cross-section TEM micrograph showing an STO layer that started as an amorphous phase (a-STO), then changing to a crystalline phase (c-STO). Fig. 3. Open in new tabDownload slide A cross-section TEM micrograph showing an STO layer that started as an amorphous phase (a-STO), then changing to a crystalline phase (c-STO). A wide crack observed between the STO and the underlying Pt layers was thought to form by a stress induced during mechanical polishing processes (cf. Fig. 2). To test this idea, we prepared the cross-section specimen of Type A sample using FIB, which is free of mechanical stressing. As expected, no layer separation was observed in the FIB-cut TEM specimen. Thus FIB cutting could indeed retain the integrity of the interface without separating these layers. Figure 4a and b are a BF and DF pair showing the plan-view of Type A sample, whereas Fig. 4c is the corresponding electron diffraction pattern. Here, we show an amorphous-to-crystalline transition region, in which crystalline STO grains have nucleated in the matrix of the amorphous phase. Each grain was found to be a single crystal, which is distributed randomly inside the amorphous phase. The corresponding diffraction pattern shown in Fig. 4c represents a superposition of both amorphous and crystalline patterns. The crystalline grains are highly bent (strained), thus exhibiting characteristic bend fringes. These bend fringes are seen as spider-like dark lines in the BF and as white lines in the DF. Consistent with the cross-sectional view, this plan-view sample of the transition region contains both amorphous and crystalline phases. With increasing film thickness, randomly nucleated crystallites grow to merge with neighboring grains, finally forming the columnar structure seen in Fig. 2. In other words, the film in the latter stage consists of a columnar structure containing randomly oriented grains. Using a published X-ray powder diffraction file [2] as well as our calculated one, we confirmed that the polycrystalline diffraction pattern in Fig. 4c was from STO. STO (SrTiO3) is one of the perovskites that have a cubic crystal with the lattice constant, α0 = 3.905 nm, and the space group, Pm3m [3]. Fig. 4. Open in new tabDownload slide (a) BF, (b) DF images and (c) the corresponding electron diffraction pattern of an STO film taken from the plan-view Type A sample. Fig. 4. Open in new tabDownload slide (a) BF, (b) DF images and (c) the corresponding electron diffraction pattern of an STO film taken from the plan-view Type A sample. Type B sample As described above, the cross-section TEM specimen of the Type B sample was also prepared by an FIB method to avoid interfacial cracking induced by mechanical polishing. Figure 5 is a BF XTEM micrograph taken from the Type B sample. The STO layer is seen to be totally crystalline (c-STO), containing no amorphous phase. The micrograph also shows that the STO layer is columnar. Fig. 5. Open in new tabDownload slide A BF XTEM micrograph showing a crystalline STO (c-STO) layer of the Type B sample. Fig. 5. Open in new tabDownload slide A BF XTEM micrograph showing a crystalline STO (c-STO) layer of the Type B sample. A plan-view specimen was also prepared from the Type B sample having the Configuration I by polishing from the substrate side. This polishing produced a plan-view STO specimen near the uppermost surface region. Figure 6 is (a) a BF image taken from the plan-view Type B sample and (b) the corresponding electron diffraction pattern. Contrary to the case of the Type A sample, this STO film is entirely polycrystalline; the electron diffraction pattern contains only the polycrystalline rings without any trace of amorphous rings. It should be noted that the diffraction rings are not uniform, but split in the form of an arc. As will be discussed later, such an arcing will occur in a textured film, when the film is tilted. In the present case, although this STO film is not deliberately tilted, it is locally buckled, thus giving the same tilting effect. This point will become clear in the following section. Fig. 6. Open in new tabDownload slide (a) Plan-view image of a polycrystalline STO film taken from the Type B sample and (b) the corresponding electron diffraction pattern. Fig. 6. Open in new tabDownload slide (a) Plan-view image of a polycrystalline STO film taken from the Type B sample and (b) the corresponding electron diffraction pattern. To understand the effect of the underlying Pt layer on the microstructure of the subsequently deposited STO film, we prepared the plan-view sample of the Pt layer from the Configuration I type sample. The microstructure and electron diffraction pattern of the stripped Pt film are shown in Fig. 7. The electron diffraction pattern is not the standard face-centered cubic (fcc) electron diffraction pattern associated with a randomly oriented polycrystalline Pt film, because few diffraction rings, such as {111} and {200}, are missing. This clearly indicates that the film is not randomly oriented but is textured. The missing lines of {111} and {200} rings suggest that this Pt film is [111] textured. Again the diffraction pattern appears to indicate local film buckling. Fig. 7. Open in new tabDownload slide (a) The microstructure and (b) electron diffraction pattern of the stripped Pt film. Fig. 7. Open in new tabDownload slide (a) The microstructure and (b) electron diffraction pattern of the stripped Pt film. To understand a microstructural correlation between the STO and the underlying Pt films, we measured their grain size distributions. It was found that both the films show very narrow size distributions; the average grain size taken from the plan-view was 40 ± 7 nm for the Pt film and 80 ± 20 nm for the STO film. There appears to be some interesting correlation in grain size distribution between the STO and the Pt films. This point will be discussed later. Texture analysis by electron diffraction As demonstrated in a diffraction pattern from the plan-view Pt film, taken at the normal incidence (cf. Fig. 7b), a systematic appearance/disappearance of diffraction rings can give an indication that there is a fiber texture in thin films. In addition, an exercise involving high-angle tilting away from the film normal direction can allow one to conduct a quantitative analysis of a fiber texture [4–7] in thin films. In this exercise, continuous rings observed at the normal incidence for a fiber-textured film will split into arcs in a systematic manner, if the film is tilted away from the film normal. As will be described in detail, a change in the diffraction pattern of textured STO and Pt films were indeed consistent with this type of tilting exercise. The STO film in the Type A sample, on the other hand, did not show any arching to the rings with high-angle tilting, thus indicating that the film was randomly oriented without the presence of any fiber texture. In the present experiment, therefore, only the Type B sample was prepared to characterize the degree of fiber texture. An example of an arc formation with film tilting is shown in Fig. 8. Here a specimen goniometer stage attached to the microscope was used to tilt the textured STO film sequentially by 20°, 25°, 30°, 35°, 40° and 45°. The tilt axis (TA) is defined by the x-axis of the goniometer stage. Well-defined arcs start showing up at the angle of ∼20° and become more pronounced with increasing angles. These arcs represent intersections between diffracting planes (lying in the 0th, 1st, and/or 2nd Laue zones) and Ewald sphere. It is seen that the arcs show up symmetrically with respect to the TA, i.e. parallel to the TA. It is clear that arcs lying along the TA are always present regardless of the degree of tilting, except that the spread angle of each arc changes with a tilt angle. A spread angle associated with each arc can be used to quantify the degree of fiber texture; the smaller the angle, the more strongly textured. A systematic pattern change can be used to determine the type of texture [6,7]. It should be cautioned that some films may contain more than one type of texture. To overcome such a difficult case, we developed a computer program for simulating textured diffraction patterns. This program is based on the method described by Tang and Laughlin [6]. A detail of the present simulation method will be published elsewhere. Fig. 8. Open in new tabDownload slide A series of electron diffraction patterns from a 111-textured STO film, obtained at various tilt angles. A tilt angle is indicated at the top right corner. Fig. 8. Open in new tabDownload slide A series of electron diffraction patterns from a 111-textured STO film, obtained at various tilt angles. A tilt angle is indicated at the top right corner. The change in the diffraction pattern seen in Fig. 8 has shown that the STO film is [111]-textured. This conclusion was reached using computer simulations. Figure 9 is an indexed electron diffraction pattern for the [111]-textured STO film tilted by β = 45°. Each arc represents a diffraction plane present in various Laue zones. For example, 2112 denoted the 211 reflections from the 2nd Laue zone (subscripted number). As expected, a part of the rings lying along the TA, which are reflections from planes in the 0th-order Laue zones, remains the same with tilting, except that the arc length changes with tilt angle. In this tilt angle of 45°, arcs associated with diffraction planes lying in both the 1st- and 2nd-order Laue zones show up strongly. Figure 10 compares (a) an experimental electron diffraction pattern of the [111]-textured STO film taken at the tilt angle, β, of 45° with (b) a computer-simulated pattern. In this simulation, the width of the diffraction lines is plotted to be proportional to relative intensity values taken from calculated ones. These theoretical intensity values were obtained using an analytic expression of atomic scattering amplitudes for electrons [8]. An angle, α, defined as the so-called texture axis distribution angle [6,7] or the fiber texture misorientation [9], is determined to be ∼3°, which indicates that the STO film is highly textured. It is noted that the matching tilt angle in the simulation is 37°, whereas the corresponding experimental value is 45°. This discrepancy in the magnitude of tilt angle between the experiment and the theory is due to experimental uncertainties and thus varies with experimental conditions. In this simulation, we took the following consideration into account; the so-called multiplicity factor of textured grains, which is defined [10] as the number of crystallographically equivalent planes giving a common reflection in the diffraction pattern, is different for textured grains from that of randomly oriented grains. Otherwise an agreement between the experiment and the simulation is reasonable. Fig. 9. Open in new tabDownload slide An indexed electron diffraction pattern from a 111-textured STO film tilted by 45°. The location of higher-order Laue zones (LZ = ±1 and ±2) is indicated below the pattern. A subscript associated with diffraction indices represents the order of Laue zone. Fig. 9. Open in new tabDownload slide An indexed electron diffraction pattern from a 111-textured STO film tilted by 45°. The location of higher-order Laue zones (LZ = ±1 and ±2) is indicated below the pattern. A subscript associated with diffraction indices represents the order of Laue zone. Fig. 10. Open in new tabDownload slide Comparison of (a) an experimental diffraction pattern from a 111-textured STO film with (b) a simulation. Fig. 10. Open in new tabDownload slide Comparison of (a) an experimental diffraction pattern from a 111-textured STO film with (b) a simulation. Again the use of computer simulations helped us to confirm that the Pt film is also [111]-textured. Figure 11 is a series of the [111]-textured Pt film tilted by various angles (20°, 30°, 40° and 47°). Again arcs represent intersections between diffracting planes (lying in the 0th, 1st, 2nd, and/or 3rd Laue zones) and Ewald sphere. Although both STO and Pt films are cubic and [111]-textured, the diffraction patterns of the tilted Pt film are very different from those of the STO (cf. Fig. 8). Figure 12 is an indexed electron diffraction pattern for the [111]-textured Pt film tilted by β = 30°. Figure 13 compares (a) an experimental pattern of the [111]-textured Pt film, taken at a tilt angle of β = 30°, with (b) a simulation (β = 35.2°). Again the discrepancy in the tilt angle is obvious due to experimental uncertainties. The texture axis distribution angle,α, was 3°, which is the same as the angle of the [111]-textured STO film. Fig. 11. Open in new tabDownload slide A series of electron diffraction patterns obtained by tilting a 111-textured Pt film at various angles. A tilt angle is indicated at the top right corner. Fig. 11. Open in new tabDownload slide A series of electron diffraction patterns obtained by tilting a 111-textured Pt film at various angles. A tilt angle is indicated at the top right corner. Fig. 12. Open in new tabDownload slide An indexed electron diffraction pattern from a 111-textured Pt film tilted by 30°. The location of higher-order Laue zones (LZ = ±1, ±2 and ±3) is indicated below the pattern. A subscript associated with diffraction indices represents the order of Laue zone. Fig. 12. Open in new tabDownload slide An indexed electron diffraction pattern from a 111-textured Pt film tilted by 30°. The location of higher-order Laue zones (LZ = ±1, ±2 and ±3) is indicated below the pattern. A subscript associated with diffraction indices represents the order of Laue zone. Fig. 13. Open in new tabDownload slide Comparison of (a) an experimental electron diffraction pattern from a textured Pt film with (b) a computer-simulated pattern. The tilt angle for (a) was 30°, whereas that for (b) was 35.2°. Fig. 13. Open in new tabDownload slide Comparison of (a) an experimental electron diffraction pattern from a textured Pt film with (b) a computer-simulated pattern. The tilt angle for (a) was 30°, whereas that for (b) was 35.2°. Origin of fiber texture in STO films It has been shown that the STO film grown on the high-temperature (∼500°C) substrate exhibited a strong [111] texture. We believe that this is caused by growth on the [111]-textured Pt layer. Platinum is a face-centered cubic crystal with the lattice constant of α0 = 3.912 nm, whereas STO is cubic with α0 = 3.905 nm. Thus the nominal lattice mismatch between Pt and STO is only 0.18%. In the case of the Type B sample, in which a substrate temperature of ∼500°C was used for growing the STO layer, it is most likely that the STO could have grown epitaxially on each grain of the polycrystalline Pt. The fact that the texture axis distribution angle, α = 3°, of the STO film was the same as that (α = 3°) of the Pt film strongly indicates the validity of our speculation. In other words, the STO copied the underlying Pt structure, making the texture axis distribution angle identical. The similarity observed in the grain size distribution between the STO (80 ± 20 nm) and the Pt (40 ± 7 nm) is believed to support our contention that the formation of the [111]-textured STO film is due to epitaxial growth on the [111]-textured Pt film. At high substrate temperature (∼500°C), an STO layer is expected to grow epitaxially on the [111]-textured Pt film due to the small lattice mismatch (0.18%). At this nucleation stage, the grain size of the STO is similar to that of the Pt. During the growth process, there will be competitions among the STO grains, in which some grains are taken over by other neighboring grains. Such a grain-elimination process during film growth was previously discussed [11] using a concept of a so-called evolutionary selection rule. In this process, the average lateral dimension of the grain size will become larger with increasing film thickness. Since we prepared the plan-view specimen of the STO at the uppermost area, their grain size is expected to be larger than that near the STO/Pt interface. This grain size difference reflects the difference in the average grain size distribution. In conclusion, the observed highly textured STO film originates from epitaxial growth of the STO on the [111]-textured Pt film. For fcc crystals such as Pt, the {111} has the lowest surface energy, because it is the highest packing-density plane. Thus it is generally accepted that the formation of the [111] texture results in Pt films. The role of the underlying TiN layer on the texturing of the Pt film is not clear at moment, because, in the present experiment, no experimental results were obtained on the structure of the TiN. The TiN layer below the Pt might have undoubtedly contributed to the [111]-texturing of the Pt. This subject is, however, beyond the scope of the present study. Comparison between two types of STO films A TEM analysis has shown that the main difference in the κ value of the STO layer between the Type A and B samples is the crystallinity of the films; the Type A sample contained an initial amorphous phase, followed by a crystalline phase, whereas the Type B sample had only a crystalline phase. Following the principle of the parallel capacitance proposed by Takashima et al. [12], we constructed a model of two-layer structure for the Type A STO film. According to this model, the dielectric constant, κT, of the whole STO layer can be expressed by the following equation: (1) where ta is the thickness of amorphous STO, tc the thickness of crystalline STO, κT the dielectric constant of the whole STO layer, κa the dielectric constant of amorphous STO, and κc the dielectric constant of crystalline STO. Here using the following experimental values, i.e. ta = 0.11, tc = 0.64, κa = 20 and κc = 200, we obtained κT = 86, which is close to the measured value of 100. The simple geometrical equation [1] can indeed explain the difference in κ observed between two types of STO films. It should be noted that the κc value was taken from an experimental value for crystalline and textured STO films. Thus, both crystallinity and texturing contribute to the improved dielectric constant κ of the STO in the Type B sample. Finally, it is important to note that the substrate temperature during sputtering is one of the most important factors controlling the κ values of STO films. Concluding remarks The origin of a difference in dielectric constant observed between two types of sputter-deposited strontium titanate (STO) films was investigated using TEM and electron diffraction methods. The first type of STO films having a low (∼100) dielectric constant initially grew as an amorphous phase, followed by the formation of a randomly oriented polycrystalline phase. The second type with a high (∼200) dielectric constant, on the other hand, grew throughout the thickness as a crystalline phase, forming columnar grains with a strong 111 texture. The film crystallinity and texture could explain the dielectric constant difference observed in two types of STO films. It can be concluded that the fabrication of high dielectric constant STO films requires the formation of a textured crystalline phase, in which the substrate temperature is one of the most crucial factors. Finally, a quantitative texture analysis demonstrated that [111] fiber-texturing in STO films could have taken place by epitaxial growth on [111]-textured Pt films. References 1 Sathyamurthy S , Salama K . Chemical solution deposition of highly oriented strontium titanate buffer layers for coated conductors , Superconductor Sci. Technol , 2000 , vol. 13 pg. L1 :10.1088/0953-2048/13/7/101 Google Scholar Crossref Search ADS WorldCat Crossref 2 Swanson H E and Fuyat R K (1953) NBS Circular 539, Vol. 1 (US Government, Washington DC) 3 Peng L-M , Dudarev S L , Whelan M J . , High-Energy Electron Diffraction and Microscopy , 2004 Oxford Oxford University Press pg. 441 Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 4 Reimer L , Freking K . Versuch einer quantitativen erfassung der textur von gold-aufdampfschichten , Z. Physik , 1965 , vol. 184 (pg. 119 - 129 ) 10.1007/BF01380673 Google Scholar Crossref Search ADS WorldCat Crossref 5 Reimer L . , Transmission Electron Microscopy; Physics of Image Formation and Microanalysis , 1993 3rd edn. New York Springer Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 6 Tang L , Laughlin D E . Electron diffraction patterns of fibrous and lamellar textured polycrystalline thin films. I. Theory , J. Appl. Cryst , 1996 , vol. 29 (pg. 411 - 418 ) 10.1107/S0021889896000404 Google Scholar Crossref Search ADS WorldCat Crossref 7 Tang L , Laughlin D E . Electron diffraction patterns of fibrous and lamellar textured polycrystalline thin films. I. Applications , J. Appl. Cryst , 1996 , vol. 29 (pg. 419 - 426 ) 10.1107/S0021889896000416 Google Scholar Crossref Search ADS WorldCat Crossref 8 Smith G H , Burge R E . The analytical representation of atomic scattering amplitudes for electrons. , Acta Crystallogr. , 1962 , vol. 15 pg. 182 10.1107/S0365110X62000481 Google Scholar Crossref Search ADS WorldCat Crossref 9 Mendibide C , Steyer P , Esnouf C , Goudeau P , Thiaudiere D , Gailhanou M , Fontaine J . X-ray diffraction analysis of the residual stress state in PVD TiN/CrN multilayer coating deposited on tool , Surf. Coatings Technol. , 2005 , vol. 200 pg. 165 10.1016/j.surfcoat.2005.02.081 Google Scholar Crossref Search ADS WorldCat Crossref 10 Vainshtein B K . , Structure Analysis by Electron Diffraction , 1964 New York Pergamon Press pg. 187 Google Scholar Google Preview OpenURL Placeholder Text WorldCat COPAC 11 van der Drift A . Evolutionary selection, a principle governing growth orientation in vapour-deposited layers , Phillips Res. Rep. , 1967 , vol. 22 (pg. 267 - 288 ) OpenURL Placeholder Text WorldCat 12 Takashima H , Wang R , Okano M , Shoji A , Itoh M . Structure and dielectric behavior of epitaxially grown SrTiO3 film between YBa2Cu3O7-δ electrodes , Jap. J. Appl. Phys , 2004 , vol. 43 pg. L170 10.1143/JJAP.43.L170 Google Scholar Crossref Search ADS WorldCat Crossref © The Author 2011. Published by Oxford University Press [on behalf of Japanese Society of Microscopy]. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
TI - Microstructure of sputter-deposited strontium titanate films
JF - Journal of Electron Microscopy
DO - 10.1093/jmicro/dfr006
DA - 2011-04-01
UR - https://www.deepdyve.com/lp/oxford-university-press/microstructure-of-sputter-deposited-strontium-titanate-films-m8G4Rvb1A2
SP - 133
EP - 142
VL - 60
IS - 2
DP - DeepDyve
ER -