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To investigate the disintegration of wet- and dry-compressed orally disintegrating (OD) tablets, with synchrotron radiation as the X-ray source.Pharmaceutical tablets are vital for the treatment of various diseases. Therefore, they are constantly developed to ensure desirable characteristics. In particular, OD tablets need to disintegrate immediately after absorbing saliva. How these tablets absorb saliva is key to enhancing rapid product development. Recently, absorption processes have been investigated using various noninvasive techniques, including X-ray radiography and X-ray computed tomography. However, X-ray radiography studies on how water without a contrast agent is absorbed, moves, and causes a tablet to swell are scarce. The use of a contrast agent is associated with some shortcomings, including complex data analysis in some instances, alterations in the viscosity of water, and potential influence on fluid transport inside the tablet, thus possibly affecting the disintegration process.Real-time X-ray radiography was used to monitor the disintegration of various tablets, while X-ray computed tomography and software were used to create 3 D images.We demonstrated how pure water penetrated the wet-compressed tablet faster than inside the dry-compressed tablet, and how the latter swelled more. X-ray computed tomography showed the presence of voids in the tablets following water absorption.Our methods are promising for nondestructive fluid absorption and transport investigations inside OD tablets.

We demonstrate that total reflection hard x-ray photoelectron spectroscopy (TR-HAXPES) is a versatile method for elucidating a difference between surface and bulk electronic states of strongly correlated electron systems, complementing conventional bulk sensitive hard x-ray photoelectron spectroscopy (HAXPES). To demonstrate the experimental feasibility of the method, we investigated ${\mathrm{La}}_{0.6}{\mathrm{Sr}}_{0.4}{\mathrm{MnO}}_{3}$ and the electron-doped high-${T}_{\mathrm{C}}$ superconductor ${\mathrm{La}}_{1.9}{\mathrm{Ce}}_{0.1}{\mathrm{CuO}}_{4}$. From the incident angle dependence of the spectral line shapes, we found that the surface-sensitive TR-HAXPES measurement equivalent to soft x-ray photoelectron spectroscopy is possible in the total reflection condition. The results strongly suggest that this method allows us to measure both surface and bulk electronic states without making any changes to experimental setup such as the energy resolution, x-ray energy, and the beamline.

Lithium-ion batteries are widely used as power sources in electric buses, railways, ferries, and other mass transportation systems. To meet the energy needs of these infrastructure systems, it is important to realize battery control that enables high-energy operation for long periods of time. The high-capacity Ni-rich cathode material NCM811 (LiNi0.8Co0.1Mn0.1O2) has attracted research interest as a candidate high-energy-density cathode material. However, NCM811 has been reported to have some degradation problems, especially when operating at potential above 4.2 V versus Li/Li+1).Furthermore, the safety of NCM811 becomes compromised with time. Therefore, understanding the aging mechanism and predicting battery aging behavior are required for effective battery control. We have found that operating NCM811 cathodes at the combination of the potential higher than 4.2 V and lower potential less than 3.6 V that accelerates aging, leading to substantial capacity loss and increased resistance. However, aging was mitigated when NCM811 batteries were operated at a higher or lower potential range. Electrochemical and chemical analyses were performed to clarify the aging mechanism. We prepared 1-Ah LTO/NCM811 pouch cells. Charge/discharge cycling tests were carried out using various state-of-charge (SOC) ranges (SOC0-100%, SOC20-100%, and SOC0-70%) at a 3C rate at 65°C. When the cell was charged at SOC100% and SOC0%, the cathode potential was set to above 4.2 V and to below 3.6 V. The capacity retention and DC resistance (DCR: SOC50%, 0.2 sec) for these cells are shown in Figure1a. The capacity retention of the cell after 1000 cycles at SOC0-100% cycling test was about 75% for the initial capacity. However, a high capacity retention of 93% was obtained at SOC20-100% cycling, despite the cell was charged at SOC100% of 1000 times. The capacity retention of SOC0-70% cycling was nearly 100%. DCR increased 2.5-times after 1000 cycles at SOC0-100% cycling, which was higher increase than that of SOC20-100% cycling and SOC0-70% cycling. To clarify the mechanism, the cathode was removed from the deteriorated pouch cells and its electrochemical properties were investigated using a three-electrode glass beaker cell. The cell was assembled using the cathode and lithium metal as a counter electrode, and a reference electrode was also prepared. The lithium-diffusion coefficient of NCM811 at the time of preparation and after 1000 cycles was measured using the galvanostatic intermittent titration technique method. In the case of a NCM811 cathode operated at SOC0-100% for 1000 cycles, there was little change for the lithium-diffusion coefficient of x < 0.8 in LixNi0.8Co0.1Mn0.1O2, but that of x > 0.8 decreased to less than 1/10. Changes in the crystal structure of the NCM811 particle surface were analyzed by scanning transmission electron microscopy–electron energy loss spectroscopy (STEM-EELS). The thickness of the surface structural change layer was calculated from the EELS spectrum. Also, the thickness and composition of surface film was analyzed by hard X-ray photoelectron spectroscopy (HAX-PES). This measurement was performed at the SPring-8 synchrotron radiation facility. From the STEM-EELS analyses, in the case of SOC0-100% cycling, the surface crystal structure of NCM811 changed from the layered type to the rock-salt or spinel-layer type. The thickness of this transition layer increased by 7 nm compared from beginning. In the case of SOC0-70% cycling, the thickness increased by only 2 nm. It is expected that the cathode operated above 4.2 V at SOC0-100% cycling. From the HAX-PES analysis, the film thickness increased by 20 nm from the initial condition after SOC0-100% cycling. But, after SOC20-100% cycling and SOC0-70% cycling, the film thickness increased was suppressed than that. Based on the results of these analyses, we proposed the following model. In the first step, the structure change of NCM811 was accelerated at high potential. As the rock-salt layer disturbed lithium diffusion, the diffusional resistance increased and the capacity during discharge decreased. In the second step, when NCM811 subjected to a higher potential was discharged to a lower potential, the lithium can’t be intercalated smoothly at the surface x > 0.8 in LixNi0.8Co0.1Mn0.1O2. As a result, the lithium near the surface reacts with electrolyte, forming a film on the NCM811 surface. As the lithium was consumed by the film-growth reaction, the cathode operating potential increased, which accelerated the first step mechanism. The combination of the first and second steps accelerated aging. But this aging can be minimized by controlling the operating voltage. Understanding of the aging mechanism will enable accurate prediction of deterioration. [1]F. Friedrich, B. Strehle, etc, Journal of The Electrochemical Society, 166, A3760-A3774 (2019) Figure 1

We present direct evaluation of a buried ferroelectric HfSiO layer beneath a top TiN electrode with MIM capacitor structure. Since inelastic mean free path for HAXPES is several times deeper than that for conventional XPS, we clearly measured Hf4f spectrum of HfSiO and revealed that chemical bonding state varied after thermal annealing of the HfSiO for crystallization. The method provides powerful assistance for such process optimization.

The X-ray absorption fine structure method was applied for the quantitative analysis of hexavalent Cr in electronic products. The pre-edge peak intensity of the Cr K-edge increased according to the hexavalent Cr amount, and the hexavalent Cr ratio was calculated quantitatively by using the intensity. By combining with inductively coupled plasma atomic emission spectroscopy measurement results that gave the total Cr amount, the absolute amount of hexavalent Cr in chromate conversion coating and plastic samples could be evaluated. The results obtained by this method were in good agreement with those obtained by the chemical analysis method. This method can be successfully applied for the determination of hexavalent Cr amount in electronic products such as chromate conversion coating and plastic.

We investigated a voltage-control spintronics memory (VoCSM) with a shunt-free design process and W spin-Hall electrode. We successfully reduced the write current to 62 μA at a 5-ns write pulse (48 μA at a 20-ns write pulse), utilizing a high spin-Hall efficiency by developing the shunt-free design process and optimized W spin-Hall electrode. Moreover, the device was very reliable, exhibiting properties such as a low write error rate ( 1 × 1012 cycles). The spin-Hall MRAM and VoCSM with the shunt-free design process and W spin-Hall electrode could lead to high-speed nonvolatile memory with low power consumption and high durability.

We have investigated the implantation fluence dependence of the local atomic structure around arsenic (As) dopant atoms in low-energy (10 keV) implanted crystalline silicon by extended X-ray absorption fine structure (EXAFS) spectroscopy performed using a high-brilliance synchrotron radiation beam from an in-vacuum undulator in a third-generation light source. To obtain complementary information on the structural properties, high-resolution transmission electron microscopy (HR-XTEM) and nanobeam electron diffraction (NBED) measurements were also performed. We present the first observation of the initial stages of lattice disorder in As-implanted Si.

1. Introduction GeSn alloy is an attractive material as a high hole mobility channel substituting Si and as a stressor for strained channels. Furthermore, modulation of band structure from indirect to direct gap by the increasing Sn composition up to 6-10 % is expected to improve the performance of optical devices [1, 2]. Then, a high-quality GeSn thin film with higher Sn concentration is a promising for higher performance and integrated devices on the Si platform. However, it has been difficult to increase Sn concentration, because the solubility limit of Sn within a GeSn film is considered to be approximately 1 atomic % [3]. Hence, a growth technique which enables the suppression of Sn segregation during GeSn growth and a characterization to analyze the surface segregation occurred with a thickness of several nm, are essential. For these purpose, we have developed a metal-organic chemical-vapor-deposition (MOCVD) method with new source gases that is safe, uniform, and industrially applicable [4]. In addition, we also investigated a hard X-ray photoelectron spectroscopy (HAXPES) and X-ray diffraction (XRD) on synchrotron technique to analyze thin GeSn films. In this presentation, we introduce high Sn concentration GeSn thin film exceeding 6% prepared by combining the new MOCVD growth and synchrotron analysis methods. 2. Experimental Thin GeSn films with the thickness of typically 30-100 nm were grown on (001) Ge substrates at low temperature (320-360 degrees) by the MOCVD method using Ge (t-C4H9GeH3) and specially prepared Sn ((C2H5)4Sn) source gases. The Sb was doped from the atmosphere with residual triisopropyl-antimony [(i-C3H7)3Sb]. The target compositions of Sn were 2%, 3%, 6%, respectively. To clarify the crystallinity of GeSn films, HAXPES and XRD were carried out at SPring-8. Since the inelastic mean free path (IMFP) is several times deeper than that for conventional X-ray photoelectron spectroscopy (XPS), HAXPES is expected to be useful to identify simultaneously the variation of chemical state at a surface part and the underlying bulk part of a GeSn film [5]. The Sn and Sb concentrations were calculated by the combination of Rutherford back-scattering spectroscopy (RBS) and secondary ion mass spectrometry (SIMS) measurements. Cross-sectional TEM was also carried out for the evaluation of the crystal quality. 3. Results and discussion Initially, we observed the splitting of the Sn3d5/2 spectrum into two peaks for 3% Sn composition GeSn film by the HAXPES measurement, whereas the spectrum of a low Sn composition (2%) GeSn film remained single (Fig.1). The binding energy of the newly split peak (M2) was lower than that of the Sn3d5/2 peak (M1) and the peak position of M1 approximately coincided with that of the 2% GeSn film. To clarify the newly split Sn3d5/2 peak (M2), total reflection mode HAXPES (TR-HAXPES) measurement was also carried out for the 3% GeSn film. As a result, only a single Sn3d5/2 spectrum was observed by the measurement. Since the position of the observed peak by the TR-HAXPES, closely coincided with the split peak (M2), the M2 was identified as a peak derived from the Sn segregation formed at the film surface. Hence, it is concluded that depth profile characterization of the Sn chemical state within a GeSn film possible by combining the HAXPES and TR-HAXPES measurements. In order to further increase the Sn concentration, we employed Sb as a surfactant [6]. As a result, neither extreme change of XRD spectrum due to strain relaxation or asymmetric structure of HAXPES by the Sn segregation was observed for the newly grown GeSn film of 6% Sn. A decrease in the broad peak intensity on the high binding energy side due to surface oxidation was also confirmed. Since the surface is more stabilized by Sb with lower interfacial free energy, it is expected that suppression of Sn segregation and uniform Sn concentration in depth direction are simultaneously achieved. The concentration distribution of Ge and Sb were confirmed by the RBS and SIMS, and it was revealed that the Sn concentration was uniform in the depth direction, and the composition of Sn and Sb was 6.6 at.% and 0.5 at.%, respectively. Hence, by combining newly developed MOCVD technique and synchrotron technique, it was confirmed that uniform GeSn thin layer with higher Sn composition was realized. Reference [1] S.Zaima, JJAP 52 (2013) 030001, [2] R.Cjhen et al., APL 99, (2011) 181125, [3] C. Thurmond et al., J.Chem.Phys. 25,(1956)799, [4] K.Suda et al., ECS J.SSST, 4 (2015) 152. [5] K.Usuda et al., MRS spring meeting, (2016), EP11.6.10. [6] X. Yang et al., IEEE Photon.Tech.Lett.12,(2000) 128. Figure 1

We experimentally demonstrate a giant voltage-controlled magnetic anisotropy (VCMA) coefficient in a crystallographically strained CoFe layer (~15 monolayers in thickness) in a MgO/CoFe/Ir system. We observed a strong applied voltage dependence of saturation field and an asymmetric concave behavior with giant VCMA coefficients of −758 and 1043 fJ V−1 m−1. The result of structural analysis reveals epitaxial growth in MgO/CoFe/Ir layers and the orientation relationship MgO(001)[110] ∥ CoFe(001)[100] ∥ Ir(001)[110]. The CoFe layer has a bcc structure and a tetragonal distortion due to the lattice mismatch; therefore, the CoFe layer has a large perpendicular magnetic anisotropy.

High-sensitivity fluorescence-yield x-ray absorption fine structure spectroscopy (XAFS) has been investigated to characterize the local structure around arsenic shallow implant in silicon. Fluorescence-yield XAFS experiments were performed using a high-brilliance synchrotron radiation beam from an in-vacuum-type undulator in a third-generation light source. In addition to investigating the efficiency of high-brilliance undulator x-rays during the fluorescence-yield XAFS measurements, we compared the analytical performance of both the wavelength dispersive spectrometer (WDS) and the energy dispersive spectrometer (EDS) based on the silicon drift detector (SDD). It was confirmed that the WDS reduces the influence of scattering background due to the high spectral resolution. Another advantage of the WDS is high counting rate measurements. It was found that fluorescence-yield XAFS using undulator x-rays combined with the WDS permits superior sensitivity measurements.

The effect of Ni to Si ratio on effective work function (Φeff) modulation with phosphorus (P) segregation at the Ni silicide/SiO2 interface was systematically investigated. To discriminate the P segregation effect from other parasitic possibilities of Φeff modulation, which are changes in Ni–Si ratio and crystallinity including crystal grain orientation near the interface, we applied a P post-doping process for Ni2Si (Ni3Si2)/SiO2, NiSi/SiO2, and NiSi2/SiO2 systems. In the post-doping process, P atoms were segregated to the Ni silicide/SiO2 interface after Ni silicide gate formation; hence, independent control of a desired interface P density can be realized. In addition, we newly developed a thin Ti-inserted NiSi2 formation process, by which NiSi2 can be formed at a temperature as low as 450 °C, thus revealing the P-segregated Φeff modulation effect at the NiSi2/SiO2 interface for the first time. As a result, the largest Φeff modulation (ΔΦeff = -0.45 eV) occurs at the P-segregated NiSi2/SiO2 interface, and a Φeff of near the Si conduction band edge (4.13 ±0.04 eV) was realized, although the obtained Φeff values with P segregation at Ni2Si (Ni3Si2)/SiO2 and NiSi/SiO2 were 4.38 ±0.01 eV (ΔΦeff = -0.32 eV) and 4.37 ±0.01 eV (ΔΦeff = -0.29 eV) for the same P dose, respectively. Moreover, we found that ΔΦeff at the NiSi2/SiO2 interface is larger than those at the NiSi/SiO2 and the Ni2Si (Ni3Si2)/SiO2 interfaces, even when the segregated P densities are the same. These results can be explained by an increase in the density of effective interface dipole for Φeff modulation at a high-Si-content interface.

A simplified method of effective work function (Phieff) control to near the Si conduction band edge (Ec) was demonstrated in the Ni fully silicided (Ni-FUSI) gate/HfSiON system. The Phieff of NiSi (4.51 eV) decreased and saturated at 4.27 eV, owing to the use of an Al postdoping process, in which the implantation of Al ions into the upper part of the Ni silicide gate electrodes was followed by low-temperature drive-in annealing ( les 500degC) . There is no degradation of the gate leakage characteristics at the Ni-FUSI/HfSiON interface. The metallic state of piled-up Al just at the Ni-FUSI/HfSiON interface seems to be responsible for the Phieff near the vacuum work function of Al. The Al postdoping process simplifies a dual metal gate process, owing to single-step Al implantation for nMOS devices without complicated metal etching process for pMOS region. The physical mechanism of bidirectional Phieff modulation of Al pileup was also investigated. It was revealed that the opposite Phieff modulation, which is the increase in Phieff, occurs, owing to the formation of interfacial Al2O3 layer at the Ni-FUSI/SiO2 interface. Although the Al2O3 state also formed, it has little influence on the Phieff value at the Ni-FUSI/HfSiON interface.

The influences of the interface layer on crystal structure, the local atomic arrangement, and the electronic and chemical structure of a GeBiTe (GBT) phase-change recording material have been investigated using X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), and hard X-ray photoelectron spectroscopy (HX-PES) methods using actual rewritable high-speed HD DVD media without special sample processing. XRD results showed that the crystal structure of laser-crystallized GBT alloy in the actual HD DVD media is the same as that of GeSbTe (GST) alloy, which has a NaCl-type structure. No differences between samples with and without interface layers were found. The lattice constant of GBT is larger than that of GST. Bi increases the lattice constant of GST with respect to the Bi substitution ratio of Sb. According to HX-PES, the DOS of in the recording film amorphous state with an interface layer is closer to that of the crystalline state than the recording film without an interface layer. From XAFS results, clear differences between amorphous (Amo.) and crystalline states (Cry.) were observed. The interatomic distance of amorphous recording material is independent of the existence of an interface layer. On the other hand, the coordination number varied slightly due to the presence of the interface layer. Therefore, the electronic state of the recording layer changes because of the interface layer, although the local structure changes only slightly except for the coordination number. Combining these results, we conclude that the interface layer changes the electronic state of the recording layer and promotes crystallization, but only affects the local structure of the atomic arrangement slightly.

We have measured K–edge X–ray absorption spectra of argon in sputtered aluminum films at a synchrotron radiation facility (the Photon Factory). We found that the energy and shape of white line change when the film is annealed at 500 °C and the spectrum becomes resembling that of argon implanted in silicon. From the analyses of the X–ray absorption spectra and TEM observation we concluded that argon exists as very small atom clusters with a diameter less than 1 nm or exist as isolated atoms in the as–sputtered aluminum film, and that the size of the clusters become as big as 10 nm diameter when the film is heated.

We investigated band-profile control by introducing interlayers between a semiconductor and metal contact layers to improve the electrical properties of GaN-based semiconductor devices. We evaluated the electronic structure of the semiconductor surface and the metal/semiconductor interface by hard X-ray photoelectron spectroscopy. We also performed Monte Carlo simulations using the Boltzmann transport equation under the potential profile obtained using the Poisson equation. The band profile in the semiconductor substrate was then examined by comparing the energy spectra from the simulations with those from the experiments. We obtained good agreement between the two results. The present experimental and theoretical methods allow one to determine the band profile near the surface of a semiconductor as well as that in a metal interface. This approach may become a useful tool in the design and/or evaluation of processing conditions.

Poly(y-benzyl glutamate) (PBG) bonded covalently to a flat substrate at a terminal position of the main chain and formed an aligned dipole layer because of its rigidity. The authors call this a poly(y-benzyl glutamate) chemical reaction alignment (PBG-CRA) film. Using the PBG-CRA film as an orienting film for nematic liquid crystals, liquid crystal molecules were oriented spirally to generate a novel chiral director field in the liquid crystal phase despite the absence of chirality in the liquid crystal molecule, the sense of which depended on that of the α-helical structure of PBG on the surface, resulting in the observation of a spiral texture. Since the liquid crystal molecules in the vicinity of the PBG-CRA film were able to respond more rapidly to an applied electric field than those for a rubbed polyimide film and werq responsive at voltage frequencies in the MHz region, we conclude from our investigations by time-resolved infrared spectroscopy that the PBG molecules are reversibly responsive to an external stimulation due to their rigidity and large dipole moments and that the dipole-dipole interaction takes place between the PBG molecules and the interfacial liquid crystal molecules.

The reliability of the silver-doped dielectric ceramic (Pb 0.875 Ba 0.125 ) 0.995 [(Mg 1/3 Nb 2/3 ) 0.5 (Zn 1/3 Nb 2/3 ) 0.3 Ti 0.2 ]O 3 was investigated to speculate on the effects of silver diffusion from internal electrodes into dielectric layers on the reliability of multilayer ceramic capacitors (MLCs). The addition of silver into the dielectric ceramic degraded the insulation resistance under humid loading conditions. Scanning transmission electron microscopy (STEM) revealed that a Pb-rich grain boundary phase exists at triple points of Ag-doped specimens. The Pb-rich phase appeared to be PbO by X-ray photoelectron spectroscopy (XPS). Degradation of insulation resistance was interpreted as a result of silver migration from the anode to the cathode through a grain boundary phase dissolved in water. Although silver diffusion from internal electrode layers in MLCs into dielectric layers was confirmed by STEM, a secondary phase was not observed. Intensive study is needed to clarify the effect of silver diffusion on degradation of insulation resistance of MLCs under humid loading conditions

Interfacial properties of single-crystalline CeO2 high-k dielectrics directly grown on Si (111) were investigated by comparing metal–insulator–semiconductor field-effect transistors (MISFETs) without any interfacial layer [(w/o-IL); direct growth of CeO2 on Si] and those with an interfacial layer (w-IL). FET characteristics, such as the drain current and the S factor, for the w/o-IL MISFET were much worse than those for the w-IL MISFET. The in-gap states attributed to the oxygen defects were detected in the CeO2 directly grown on Si by x-ray photoelectron spectroscopy measurements. The large interface state density induced by the oxygen defects at the CeO2/Si interface may deteriorate the w/o-IL MISFET performances.

Poly(γ-benzyl-L-glutamate)(PBLG) reacts with a silane coupling agent on a silicon crystal surface to form a molecular oriented film; the reaction yield was determined to be 77% by X-ray photoelectron spectroscopy and the orientation of PBLG molecules attached to the substrate was interpreted based on the attenuated total reflection spectrum.

The reaction of lithocholic acid with silane coupling agent on a Si crystal surface was analyzed with FT-IR(ATR), XPS, and contact angle. The generation of amide bonds within 1nm of the Si surface was confirmed with XPS. The yield of amide was 84%. An abnormal IR absorption was observed in the amide band region.

Silicon and nitrogen incorporated Hf oxide (HfSiON) is considered to be a promising alternative gate insulator for next‐generation MOSFETs. EXAFS and GIXS (Grazing Incidence X‐ray Scattering) have been applied to the characterization of amorphous HfSiON films at SPring‐8. Novel cluster models have been suggested based on the analogy to the ordered states for the Zr‐O‐N ternary system.

We propose a feasible integration scheme for dual FUSI/HfSiON CMOS with low work function metal pile-up to nMOSFET. A newly developed post phase change process to Ni3Si and composition-dependent diffusivity of Al realize simplified integration of 4.3 eV/4.8 eV. Moreover, direct WF lowering of Pt2Si with metal pile-up realizes 4.3 eV/4.9 eV.

The influence of the interface layer to the local structure for atomic arrangement of a GeBiTe phase-change material was investigated by using XAFS on the actual rewritable HD DVD media.

The paper demonstrates large effective work function (Phieff) modulation towards Si band-edges based on physical and chemical nature of interfacial impurities at Ni-FUSI/SiON and HfSiON interfaces. The authors clarify the influence of Ni-silicide phase on the Phieff modulation with dopant segregation. Phieff of 4.14 eV is obtained with a combination of phosphorous ion implantation last (IIL) doping and newly developed low temperature NiSi2 formation process. The paper also proposed the realistic Phieff modulation with Al-segregation at Ni-FUSI/HfSiON using IIL-doping process

The physical mechanism of work function modulation caused by impurity pileup at Ni-FUSI/SiO(N) interface were investigated. We proposed and verified a new model which can explain the Phim-eff modulation both nMOS (As P and Sb) and pMOS (B). In our model, the position and concentration of impurity at interface determine the direction and the extent of Phim-eff modulation. We have also developed a new method to introduce impurity atoms at the interface after FUSI gate formation, in which the amount of Phim-eff modulation is higher than that for the conventional process

We have investigated the reason behind the enhancement of dielectric constant ("), which occurred in CeO2 directly grown on Si(111). " of directly grown CeO2 is enhanced to 52, which is twice as large as the reported value. From in-plane X-ray diffraction measurements and electron diffraction pattern observations using a transmission electron microscope, it has been found that the lattice spacings in CeO2 were isotopically expanded by 0.6%, as compared with the reported values in bulk CeO2. In addition, from X-ray photoelectron spectroscopy measurements, the existence of oxygen defects in CeO2 was confirmed. The oxygen defects in CeO2 may cause the decrease in coulomb interaction in the ionic crystal, resulting in the expansion of lattice spacings. The enhancement of ion movability, due to the expansion of lattice spacings is considered as the reason behind the enhancement of ". [DOI: 10.1143/JJAP.43.1795]

X-ray photoelectron spectroscopy was used to study a lead-based relaxor dielectric ceramic to identify the grain-boundary phase most likely to be responsible for the insulation degradation of relaxor dielectric ceramics under humid loading conditions. The grain-boundary phase consisted mainly of lead and oxygen. The binding energies of Pb4f7/2 and O1s in the grain-boundary phase were found to be 137.3 eV and 528.8 eV, respectively, and these values agreed well with those for Pb3O4 and PbO2. In addition, the broadness of the Pb4f7/2 peak suggested the presence of PbO. Measurements were made of lead dissolution from dielectric ceramics in hot water; specimens with a grain-boundary phase gave a 30 to 50 times greater lead concentration in the hot water than specimens without a grain-boundary phase. This demonstrated that the grain-boundary phase easily dissolved in hot water. Thus, it was concluded that the grain-boundary phase contained water-soluble PbO2 and PbO. The results strongly supported the resistance degradation mechanism of relaxor dielectric ceramics under humid loading conditions as previously proposed by the authors.

Ultra-thin nitrogen incorporated ZrO/sub 2/ (ZrON) film is successfully prepared by low temperature oxidation of ZrN. Capacitance equivalent thickness (CET) of 15 /spl Aring/ with Jg=1 mA/cm/sup 2/@ Vg=-1 V is demonstrated. There is no increase in CET up to 1000/spl deg/C. Silicide formation at poly-Si/ZrO/sub 2//Si stack at high temperature annealing is also inhibited. In addition, the boron penetration from p+ poly-Si to Si substrate is substantially suppressed.

It was found that a high concentration of holes was generated without any post‐annealing by boron ion implantation into silicon in the high‐dose region of more than 1×1016 cm−2. X‐ray photoelectron spectroscopy and Fourier transform infrared absorption spectrum revealed that B12 icosahedra were created just after implantation. The generation of holes can be explained by the model in which B12 icosahedra act as a double acceptor.

Ti-Si-O films were sputter deposited from TiO2+SiO2 composite targets with various SiO2 content. The phase separation occurred for every SiO2 content used in this experiment (from 14% to 75%) and it has been revealed that nanocrystalline (TiO2)1-x(SiO2)x films in which anatase TiO2 forms tiny grains were obtained when x in the film is larger than 0.26. The tiny grain was effective for suppressing the thermal grooving phenomenon of the thin films by the post deposition annealing which leads to the leakage current increase. The dielectric constant of the nanocrystalline film was varied with the SiO2 content from the value of the bulk anatase to SiO2.

Poly(γ-benzyl-L-glutamate)(PBLG) reacts with a silane coupling agent on a silicon crystal surface to form a molecular oriented film; the reaction yield was determined to be 77% by X-ray photoelectron spectroscopy and the orientation of PBLG molecules attached to the substrate was interpreted based on the attenuated total reflection spectrum.

A metal-insulator transition was observed in the layered cuprate ${\mathrm{Bi}}_{2\mathrm{\ensuremath{-}}\mathit{x}}$${\mathrm{Pb}}_{\mathit{x}}$${\mathrm{Sr}}_{2}$${\mathrm{Ca}}_{0.3}$${\mathrm{Y}}_{0.7}$${\mathrm{Cu}}_{2}$${\mathrm{O}}_{8+\mathit{d}}$, where the carrier concentration is not changed but the structural modulation was relaxed with increasing lead content x. Resistivity measurements and x-ray-photoelectron-spectroscopy (XPS) valence-band spectra manifested the occurrence of the metal-insulator transition; XPS core-level spectra, together with the results of a chemical analysis, confirmed that in this system the degree of the electron filling is constant. This metal-insulator transition is believed to arise from the change in the Cu-O-Cu bonding angle, as well as those in some nonlayered transition-metal perovskites.

Electronic states and magnetic properties in the layered perovskite vanadium oxides Srn+1VnO3n+1 were compared to those in the high-Tc cuprate superconductors. It was revealed that the electronic states in metallic Srn+1VnO3n+1 were described as the low U metal, while the insulating Sr2VO4 had the markedly different electronic structure. In Sr2VO4 the main portion of the occupied vanadium d states was interpreted to exist below oxygen 2p states in the simplest scheme of the electronic structure. Magnetic properties of Sr2−xLax−VO4 were discussed in conjunction with the structural phase transitions.

A high hole concentration region of about 1×1021 cm-3 was generated without any post-annealing by the implantation of high doses of boron into silicon substrates. X-ray photoelectron spectroscopy (XPS) measurement and Fourier transform IR spectroscopy (FTIR) absorption spectra revealed that B12 icosahedra were created in as-implanted samples. A new model of the generation of holes is proposed in which B12 icosahedron acts as a double acceptor.

The effects of dopant type and dopant concentration on the native oxide growth in air on the silicon surface were investigated. The oxide thickness was measured by X-ray photoelectron spectrometry (XPS). The oxide was thicker on n-type Si than on p-type Si in early oxidation. The oxide increased linearly with the dopant concentration. This enhancement of oxidation was assumed to be caused by vacancies near the surface in the silicon bulk.

Influences of Ni silicide phases on the effective work function (Φeff) modulation effect with Al incorporation has been investigated in the Ni silicide/HfSiON systems. We formed metal-insulator-semiconductor capacitors with Al incorporated Ni silicide (NiSi, Ni2Si, and Ni3Si) gates on HfSiON by Al solid-phase diffusion (Al-SPD) process or Al ion implantation (I/I) process. In the Al-SPD process, Al is deposited on Ni silicide gate. In the Al-I/I process, Al ions were doped in the upper part of Ni silicide layer. In both cases, we performed Al drive-in annealing under the condition of 450 °C for 30 min in N2 ambient. It is found that the flat-band voltage (Vfb) values of Al incorporated NiSi and Ni2Si gates shift negatively and identical independent of Al incorporation processes. A highly concentrated Al piled-up layer, which induces Φeff modulation to Al-Φeff value, seems to correspond to the Vfb modulation. On the other hand, Al incorporation has little influence on Φeff at the Ni3Si/HfSiON interface. We...

In order to elucidate influences of nitrogen on the change of effective work function (ΔΦeff) with impurity segregation, we systematically investigated the ΔΦeff at arsenic (As) and boron (B) segregated NiSi∕SiO2 and NiSi∕SiON interfaces. These impurities are introduced to NiSi∕SiON (SiO2) interfaces by using the conventional predoping process. It was found that increase in Φeff with B segregation is suppressed as low as ΔΦeff=+0.05eV at NiSi∕SiON interface compared to ΔΦeff=+0.14eV at NiSi∕SiO2 interface, though there is little change in decrease of Φeff with As segregation. Moreover, the opposite (negative) Φeff modulation occurred at NiSi∕SiON interface in the case of low B dose. We also performed the B postdoping process, in which B atoms were introduced after Ni silicide gate formation with lower thermal process (∼500°C) than conventional predoping process (∼1000°C). A large ΔΦeff of +0.2eV occurred even at NiSi∕SiON system in the postdoping process. Based on the results of backside x-ray photoelectr...

An effective work function (Φeff) modulation caused by impurity doping in Ni-FUSI/SiO2 systems has been systematically investigated. To clarify the physical origin, we reveal the relationship between changes of Φeff modulation factors at gate electrode interfaces and Φeff modulation ranges (ΔΦeff) in two different doping processes (predoping and post-doping). In the predoping process, in which impurities (As or B) are implanted into polycrystalline Si gate before Ni fully silicided gate formation, both the crystal structure of the Ni silicide layer and the impurity concentration at the Ni silicide/SiO2 interface change depending on the impurity species. On the other hand, the impurity post-doping process, in which impurities are implanted and introduced to the Ni silicide/SiO2 interface after Ni silicide formation, makes it possible to introduce the desired amount of impurities into the interface without any structural change of the Ni silicide. In both cases, dependence of ΔΦeff on interface impurity con...

We have investigated the reason behind the enhancement of dielectric constant (ε), which occurred in CeO2 directly grown on Si(111). ε of directly grown CeO2 is enhanced to 52, which is twice as large as the reported value. From in-plane X-ray diffraction measurements and electron diffraction pattern observations using a transmission electron microscope, it has been found that the lattice spacings in CeO2 were isotopically expanded by 0.6%, as compared with the reported values in bulk CeO2. In addition, from X-ray photoelectron spectroscopy measurements, the existence of oxygen defects in CeO2 was confirmed. The oxygen defects in CeO2 may cause the decrease in coulomb interaction in the ionic crystal, resulting in the expansion of lattice spacings. The enhancement of ion movability, due to the expansion of lattice spacings is considered as the reason behind the enhancement of ε.

Sr(Ti1-x ,Ru x )O3 (STRO) epitaxial thin films were deposited on single-crystal SrTiO3(100) substrates using the inductive-coupling-plasma-induced RF magnetron sputtering method without oxygen. The electrical conductivity of STRO films increases with Ru concentration and levels of the Ru 4d states are observed in the band gap of SrTiO3 by X-ray photoelectron spectroscopy (XPS) analysis. These results are consistent with those obtained by first-principles calculations. Thermodynamic stability increases with the decrease of Ru concentration, and STRO (x2 atmosphere at 600°C. This high resistance against reductive processes indicates that STRO (x

Diffusion of carbon in SiO2 films and its segregation at the Si/SiO2 interface were investigated using carbon-incorporated borophosphosilicateglass (BPSG) films and carbon-implanted SiO2 films. It was found that carbon atoms diffuse in SiO2 film at a temperature as low as 500° C. Carbon atoms segregated at the Si/SiO2 interface and induced positive charge. The positive charge density was proportional to the segregated carbon concentration. Field emission transmission electron microscopy (FE-TEM) and electron energy loss spectra (EELS) observations revealed that carbon atoms exist on the SiO2 side of the interface, and another carbon-rich phase is formed in S i O 2.

A high hole concentration region of about 1×1021 cm-3 was generated without any post-annealing by the implantation of high doses of boron into silicon substrates. X-ray photoelectron spectroscopy (XPS) measurement and Fourier transform IR spectroscopy (FTIR) absorption spectra revealed that B12 icosahedra were created in as-implanted samples. A new model of the generation of holes is proposed in which B12 icosahedron acts as a double acceptor.

The applicability of the soft X-ray standing-wave (SW) method to surface structure determination is discussed by investigating the SW signals of c(2×2)Cl/Ni(100). The measurements of reflectivities for Ni(200) Bragg reflection at nearly normal incidence make it possible to determine the mosaic width (0.3°) of the Ni(100) crystal employed, and the Cl-K fluorescence yield spectrum reveals that Cl atoms are located 0.04Å above the Ni(200) lattice plane. The experimental and analytical error is estimated to be 0.04Å, which allows us to discuss detailed surface structure.