The calibration service for partial pressure analyzers (PPA) has been carried out from April in 2007 at NMIJ/AIST using a two-stage flow-dividing system. The pressure range is from 10^-6 to 10^-4 Pa and the test gases are N₂, Ar, He and H₂.
  Results of the calibration for two types of PPA were also shown. The sensitivities of both PPAs were almost constant in the pressure range from 10^-6 to 10^-4 Pa, while they changed significantly with pressure higher than 10^-4 Pa. The calibration uncertainties mainly caused by the instability of PPA indication were about 7% (confidence level 95%). The stability of sensitivities of both PPAs was in about 15% for 7 months.

抄録全体を表示

  Conductance of a thin cylindrical orifice is calculated farily accurately by an approximate equation. However, a practical orifice may have rounded edges and tapered shape. Influence of these deformation on the conductance was studied by Monte Calro simulation for thickness of the orifice L=0-0.1r, where r was the radius of the orifice, beveled depth ΔL=0-0.002r, angle of beveled edge θ=0-90° and difference of radius between inlet and outlet sides Δr=0-0.002r. Results are 1) the conductance increases for 0.08% by beveling edge by 0.002r at the beveling angle of 45°, and the increase was proportional to ΔL, 2) an increase caused by beveling both inlet and outlet sides was almost twice as large as that caused by beveling either side, 3) an increase caused by beveling either side at the beveling angle of 20° was more than a half of an increase at the angle of 90° (reducing orifice thickness ΔL), 4) an increase caused by tapering radius Δr was almost a half of the increase by enlarging the radius Δr. These results were explained by an approximate equation based on a simple model.

抄録全体を表示

  We have developed an ion beam milling system enabling effective, gentle and uniform milling of EUV multilayer surface of an imaging mirror for accurate compensation of the reflection phase error. An Ar ion beam of a large 150 mm in diameter accelerated at a low 500 V to avoid surface roughening is irradiated through a template selecting the areas of milling. The Ar beam profile has a quadratic distribution within 100 mm in diameter with an ion current of 0.1 mA/cm² at the center (r=0 mm) and of 40% less 0.06 mA/cm² at the peripheral (r=50 mm) as estimated by trench milling depth measured by an optical surface profiler (WYKO). This was also confirmed by a new detection system composed of an electrode array. A correction mask has been designed for even millig of the selected area of the sample. The milling rate of a Mo/Si multilayer with the uniform ion beam was found to be 2 min/period.

抄録全体を表示

  We deposited Pb(Zr,Ti)O₃ (PZT) films on MgO(100) substrates at 440°C with sinter or powder target and investigated the effects of films of targets on the PZT film growth. The PZT films with (101)-orientation where they hardly included impurity phases were deposited by the use of the sinter target. The composition of the film was approximately a stoichiometry, and the growth rate deposited with the sinter targets was higher than that with the powder targets.

抄録全体を表示

  An exposure of a cleaved MgO(001) surface to water generates hydroxyl (OH) and/or magnesium hydroxide (Mg(OH)₂) on the MgO surface. We prepared OH or Mg(OH)₂ rich surface by different dose of water. The change of the surface composition (MgO, OH, Mg(OH)₂) by heating (room temperature ~200°C) was investigated with O1s spectra by X-ray photoelectron spectroscopy. The samples were heated by baking the vacuum chamber. In hydroxyl surface the OH component reduced to about 30% after the heating of 200°C. On the other hand, in Mg(OH)₂ rich surface, the Mg(OH)₂ component did not change by same thermal treatment.

抄録全体を表示

  We investigated the adsorption process of copper phthalocyanine (CuPc) on the clean and the hydrogen terminated 6H-SiC(0001)-(3×3) surfaces using scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy and Auger electron spectroscopy. When CuPc was deposited on the clean (3×3) surface, we observed bright 1-spot shapes in the STM image. These protrusions with 1-spot shape correspond to the CuPc molecules adsorbed on the clean (3×3) surface. When CuPc was deposited on the hydrogen-adsorbed (3×3) surface, both bright 1-spot and 4-spots shapes appeared. These results indicate that the interaction between CuPc and the surface structure affects the shape of the CuPc in the STM image.

抄録全体を表示

  Formation process of nanoscale ruthenium silicide islands on a Si(111) surfaces was studied with scanning tunneling microscopy for the first time. The ruthenium silicide islands were formed and grown on the only disorder-region, and small island grew up in three dimensions by incorporation of clusters including Ru exist on disorder-region and silicon atoms during thermal annealing. As the sizes of islands approaches 400 nm² or more, the growth in two dimensional in a plane was limited, and it grew up in the direction of height. We will discuss about the formation process of ruthenium silicide on a Si(111) surface.

抄録全体を表示

  To understand the various surface morphology of ionic crystal that is irradiated by electrons, the surface channeling technique of ion beam is used. The energy spectra and the channeling-dips are measured by the detection of 550 keV proton beam scattered from the electron-irradiated surface of KCl(001). After the electron-irradiation, the roughness of the sample surface is observed by an Atomic force microscope. The results of these experiments are compared with the calculated results of a computer simulation. The proton beam which directed along the <100> axis penetrates into the crystal and is scattered at large angle. This result is due to the surface morphology changed by the electron-stimlated-desorption.

抄録全体を表示

  We have developed a new Wide Acceptance Angle Electrostatic Lens (WAAEL) and applied that as display-type electron energy analyser. Our present lens achieves ±60° (1π sr) acceptance angle and has a good focusing capability with 5-times magnifications. The relative energy resolution is typically from 2 to 5×10^-3 and depends on the emission area on the sample, as well as, on the diameter of exit aperture. Some preliminary results and discussions related to its energy resolution are shown.

抄録全体を表示

  Desorption of cluster ions (Ne_n⁺) from a surface of solid Ne following 1.2 keV Ar⁺ ion bombardment has been investigated. We have measured the desorption yield of the cluster ions as a function of thickness of Ne film. Kinetic energy measurement of mass-selected clusters is also presented. These results allow us to discuss the desorption mechanism of the cluster ions.

抄録全体を表示

  Structure and properties of Ti films deposited by direct current (dc) magnetron sputtering and pulsed dc magnetron sputtering with or without inductively coupled rf plasma assist have been investigated for various discharge pressures. With inductively coupled rf plasma assist, (1) resistivity of Ti films decreased, (2) surface became smooth, and (3) light reflectance increased, in particular, for a discharge pressure of 2.0 Pa, compared to those of Ti films deposited by conventional dc sputtering. By cross-sectional SEM investigation, it was found that Ti film deposited by pulsed dc sputtering with rf-plasma-assist at a pressure of 2.0 Pa became denser than that of Ti film deposited by dc sputtering without rf-plasma-assist at a pressure of 2.0 Pa. It is presumed that a Ti film with a fine columnar structure results from the enhancement in the energy transferred to the surface of a growing film due to the increase in ion fraction and ion energy in the combination of pulsed dc discharge and inductively coupled rf discharge.

抄録全体を表示

  The crystallographic structure of Mn-Ir layers and the magnetic property of Mn-Ir/Co-Fe bilayers were investigated for Ar pressure, P_Ar, and Kr pressure, P_Kr, for the deposition of the Mn-Ir layer. When Ar was used as the sputtering gas, the blocking temperature, T_B, was steeply decreased with decreasing P_Ar, and became T_B=220°C at P_Ar=0.04 Pa. However, in the case of Kr gas, T_B was 320°C at P_Kr=0.04 Pa. The surface roughness, R_a, of bilayers at P_Ar=0.04 Pa was lowered, comparing to that at P_Kr=0.04 Pa. The X-ray diffraction profiles showed that the superlattice diffractions from the ordered Mn₃Ir phase were detected around the pressures P_Ar=0.2 Pa-2.0 Pa and P_Kr=0.04 Pa-2.0 Pa. In P_Ar≤0.1 Pa, the damage cased by the recoiled Ar ions was suggested as an origin of the decreasing T_B and the disappearance of Mn₃Ir phase.

抄録全体を表示

  We have developed a surface conductivity measurement system for a UHV electron microscope (UHV-EM). The sample surfaces were prepared in the UHV-EM and their structures were observed in situ by reflection electron microscopy and diffraction (REM-RHEED). After the sample preparation, the samples were cooled down to RT and the conductance measurement was carried out. The Si(111)-7×7 and Si(111)-√3×√3-Ag structures were used as sample surfaces which were prepared on the Si(111) vicinal surface inclined toward the [112] direction by 1°. The resistance of the 7×7 structure is much larger than that of the √3×√3-Ag structure and this is consistent with the previous report. This indicates that we can measure the surface conductivity by using our system.

抄録全体を表示

  The localized removal of a polyamid-imide (PAI) insulator films (thickness of 10 μm) coated on a copper winding wire of 90 μm diameter using an atmospheric-pressure microplasma jet (APμPJ) was investigated. The APμPJs of Ar and Ar/O₂ gases were generated from the tip of a stainless steel surgical needle having outer/inner diameters of 0.4/0.2 mm by a RF excitation of 13.56 MHz. The insulator films around the copper wire were completely removed by the plasma irradiation from a certain direction without fusing the wire. The removal time decreased with increasing rf power and/or by O₂ addition (5%). The removal mechanism of the PAI films was attributed to chemical etching by atomic oxygen radicals. The removal time was only 3 s at an Ar flow rate of 200 ml/min and a RF power of 4 W. Fluorescence microscopy and scanning electron microscopy images revealed that good selectivity of the insulator film to the copper was achieved.

抄録全体を表示

  We measured gas composition and its changes in the radio frequency glow discharge plasmas even near electrodes using a quartz sensor, whose output depends on molecular weight, viscosity and pressure of gas. By normalization on temperature, which mostly affects quartz sensor output particularly near the electrodes for the plasmas, the gas composition information can be obtained. Finally, this could make it possible to derive spatial distributions of the gas composition in the plasmas between the electrodes and chamber inner wall. The measurement was applied for low pressure hydrogen plasmas, which revealed that the gas composition change is attributed to the increase in carbon monoxide, methane and ethylene, probably produced at chamber inner wall. Sensitivity of the measurement was found to be better than 1 vol%.

抄録全体を表示

  Etching yields of SiO₂ by CF₃ ion beam injections with or without simultaneous light irradiation have been measured by a low-energy mass-selected ion beam system. A Xe Lamp, an L2D2 lamp, an Ar ICP (inductively coupled plasma) or a VUV (Vacuum Ultraviolet) Lamp was used separately as the light source. The etching yield is the ratio of the number of incident ions to that of removed atoms. The obtained SiO₂ etching yields by simultaneous irradiation of CF₃ ions and photons from the light source were smaller than those by ion beam irradiation only. This difference in etching yields may be caused by modification of CF_x polymer formation on the substrate surface during the beam etching process.

抄録全体を表示

  Hafniun nitiride field emitter array (HfN-FEA) was fabricated and the durability of HfN-FEA was evaluated. As the durability evaluation, we operated HfN-FEA in two different ways. One was long-time operation, and the other was the operation at elevated temperatures. HfN-FEAs worked stably for 100 hours and could be operated at 100°C. It was shown that HfN-FEA has a long life and capability of operation at high temperature. The insulating properties, however, became worse through these operations.

抄録全体を表示

  The most common use of the SPM, especially AFM, is the topography imaging. Therefore, the establishment of accurate imaging of surface microstructures is strongly demanded. The most significant distortion in AFM image is induced by the tip shape whenever the sample surface contains features with aspect ratios comparable to the tip apex size. The acquired AFM image is a convolution or dilation between the tip shape and the sample topography. To restore the original profile, a numerical deconvolution or erosion procedure using a precise tip shape function is required. In this study, we propose a new technique for restoration of AFM images using certified particle size standards or standard nano-spheres. First, AFM topography images of the nano-spheres dispersed on flat substrates such as Si(001) wafers are taken. Then, tip shape function is determined by numerical calculation. Next, surface topography of unknown sample can be restored by using the experimentally determined tip shape function. Assuming that the nano-particles are perfect spheres, the tip shape function can be determined. The real surface topography of an unknown sample surface is dilated to the scanned surface topography image by the tip shape function. Therefore, it is possible to extract the most probable surface morphology from the observed AFM topography image using the tip shape function. The experimental demonstration was performed by using 100 nm diameter standard nanospheres.

抄録全体を表示

  We report the characterization and comparison of organic field-effect transistors (OFETs) based on vapor-deposited pentacene and a soluble pentacene precursor 13,6-N-Sulfinylacetamidopentacene in solution. The gate insulator, poly (4-vinylphenol) (PVP), was crosslinked by heat or UV irradiation. Spin-coated pentacene precursor film changed to pentacene film after heating in vacuum or nitrogen; and the film structure was characterized by the UV-visible absorption spectra and X-ray diffraction (XRD). Results show that the film structure of heated pentacene precursor is similar to that of the vapor-deposited pentacene but not exactly the same. Soluble pentacene precursor shows easier processability for fabrication of high-performance solution-processable OFETs. The determined carrier mobility for vapor-deposited pentacene film is in the order of 10^-1 cm²/Vs, and for soluble pentacene precursor is in the order of 10^-2 cm²/Vs.

抄録全体を表示

  Approximately 200-nm-thick transparent conducting GZO films (ZnO doped with 5 wt.% Ga₂O₃) have been deposited on glass substrates at room temperature using a pulsed laser deposition (PLD) using Nd:YAG laser (λ=1064 nm). It was recognized that the work function of the GZO films increased from 4.6 eV for the as-deposited state to 5.1 eV for the annealed state at 400°C.

抄録全体を表示

  ZnO thin films on plastic resin substrates were prepared by RF magnetron sputtering. Substrate used polycarbonate of plastic resin. ZnO thin films changed sputtering time and RF power and produced it. Surface morphology were studied by scanning electron microscopy (SEM) and atomic force mi-croscopy (AFM). Adhesive power of thin films on substrates were studied by peel test. Transparency and surface unevenness of ZnO thin films on plastic resin substrates were able to be improved by lowering RF power. ZnO thin films on plastic resin substrates found that adhesive power was stronger than ITO thin films on plastic resin substrates.

抄録全体を表示

  Approximately 230 nm-thick Al-doped transparent conducting zinc oxide films (AZO) have been deposited on Cyclo Olefin Polymer (COP) substrates with ZnO buffer layer fabricated under oxygen partial pressure of 0.5~5.3 Pa, by pulsed laser deposition (PLD) using ArF excimer laser (λ=193 nm). When the ZnO buffer layer was fabricated with oxygen partial pressure of 5.3 Pa, the lowest resistivity obtained for the AZO film was 4.12×10^-4 Ω•cm.

抄録全体を表示

  The effect of an external magnetic flux on the substrate current and structural properties of Cu thin films was investigated. These films were prepared by magnetron sputtering with an external solenoid coil arrangement assisted by inductively coupled plasma (ICP). When unbalanced magnetron sputtering with an external magnetic flux of 4 mT assisted by ICP was used, the current flowing into the substrate due to Ar⁺ ions and sputtered Cu⁺ ions was 44 mA, which is about 2.3 times greater than that of a conventional magnetron sputtering system. From X-ray diffraction (XRD) observations it was found that the intensities of the Cu(111) and Cu(200) peaks vary significantly with external magnetic flux. The intensity of the XRD peak for Cu(111) increased and that for Cu(200) decreased when the external magnetic flux was increased from 0 mT to 4 mT. Atomic force microscope images of thin films deposited at different external magnetic fluxes show that the average surface grain size at 0 mT is 38.4 nm and that at 4 mT is 85.4 nm.

抄録全体を表示

  Nitrogen doped tungsten oxide thin films were prepared by RF reactive sputtering in a gas mixture of argon, oxygen and nitrogen at room temperature. As a result of X-ray photoelectron spectroscopy, it was thought that the doped nitrogen in the films is bonding to tungsten of WO₃ bonding states as anion and exits in substitution sites in WO₃. The optical absorption edge was shifted to lower energy region with nitrogen doping. The nitrogen doped thin films exhibit a coloration to black from transparent yellow by electrochromism. Additionally, a new peak at 2.3 eV related to nitrogen doping is observed in the spectra of color center at bleaching process.

抄録全体を表示

  Approximately 30 nm thick MoO₃ films were deposited on glass or polycarbonate substrates by Pulsed Laser Deposition Method using ArF excimer laser (λ=193 nm). For films deposited on glass substrates, transmittance change between the as-deposited and the annealed (340°C for 10 min) states was about 40% at the wavelength of 405 nm. This increase in transmittance was presumably caused by a transformation of oxygen-deficient as-deposited state into oxygen-sufficient annealed state through an annealing-induced reaction involving oxygen absorption, which was confirmed by XRD spectra. The value of CNR for 30 nm thick film grown on polycarbonates was about 50 dB at the write power of 3.0~11.0 mW. The value of CNR for 30 nm thick film with the protection layer of 30 nm was 50 dB at the peak power of 9.0~17.0 mW. These results give a characteristic feature of the wide write-power margin.

抄録全体を表示

  BiO_x films were prepared on the glass and polycarbonate substrates by reactive rf magnetron sputtering using Bi target with the aim of application to optical recording. It was found from XRD patterns and XPS spectra that both metallic Bi and Bi₂O₃ crystalline phases coexist in the deposited film under conditions with proper O₂ flow. XPS spectra after annealing showed the enhancement of spacial phase separation into Bi and Bi₂O₃ phases. Reflectivity enhancement of BiO_x films on the glass and polycarbonate substrates after annealing revealed optical recording ability for blue laser irradiation. Prepared disk with film under proper sputtering condition achieved CNR of 45.7 dB for 405 nm laser irradiation with power of 3 mW.

抄録全体を表示

  Polythiophene derivatives in π-conjugated polymers have been attracting the attention of researchers as derivatives retaining extensively potential applications in optoelectronics such as optical switches, optical logic circuits, optical integrated circuit (IC) and so forth. As π-conjugated polymers have high non-localized π electron density, the thin film prepared by π-conjugated polymers has the possibility of a large third order nonlinear optical susceptibility occurring from the thin film. In this study, the π-conjugated polymer used is regioregular poly (3-hexylthiophene-2, 5-diyl) {P3HT}. The substrate preparing P3HT thin film is quartz glass treated by octadecyltrichlorosilane (ODTS) or hexamethyldisilazane (HMDS). P3HT thin films are prepared by a drop-casting on it formed on the surface of quartz glass with self-assembling monolayer (SAM) [ODTS or HMDS]. The molecular orientation or alignment of P3HT thin films with and without SAM is performed using an X-ray Diffraction (XRD) spectrometer and UV/Vis spectrophotometer. Based on these results, the nonlinear optical characteristics of P3HT thin films with and without SAM are performed and investigated with the third harmonic intensity measured by the Maker fringe method.

抄録全体を表示

  Optical bistable devices have attracted much attention for application to optical-optical switch and so forth. We have prepared an optical bistable device of quasi-waveguide constituted comprise of a triangular prism and a poly (3-hexylthiophene)/poly (methyl methacrylate) composite thin film. The thin film was prepared by the spin coating method and drop casting method. With both the thin films, optical bistability was clearly distinguished. The optical bistable characteristics of the quasi-waveguide prepared by the spin coating method can be observed with lower laser power intensity than that by the drop casting method.

抄録全体を表示

  Polymer thin films were prepared by RF sputtering with argon (Ar) and tetra-fluorocarbon (CF₄) gases. Four fluorocarbon polymers, poly(tetra fluoro ethylene) (PTFE), tetra fluoro ethylene-perfluoro alkylvinyl ether copolymer (PFA), fluorinated ethylene propylene copolymer (FEP), poly(vinylidene di fluoride) (PVDF) were used as the sputtering targets. Molecular structures of sputtered fluorocarbon thin films were analyzed with x-rays photoelectron spectroscopy (XPS) and fourier transform infrared spectroscopy (FT-IR). Wettability of these polymer thin films was estimated with contact angles of water droplets. The contact angles increased with increase of the F/C ratio (fluorine for carbon) of the thin film. PTFE target prepared by a spin coat method was also used for the sputtering target, and analyzed the elemental compositions of the target after the sputtering. The F/C ratio of the polymer thin film prepared by the sputtering with CF₄ was almost the same value as that of the thin film with Ar. However, the C/F ratio of the target after the CF₄ sputtering was much higher than that after the Ar sputtering.

抄録全体を表示

  Four kinds of metal, such as aluminum, copper, indium and tin, thin films were deposited onto polyester (PET) substrate by a conventional vacuum evaporator and evaluated their tensile and adhesion properties. The tensile property was estimated by observations of micro-cracks of the thin films due to the tensile test at 150°C. The tensile property of the metal thin films seems to relate with Brinell hardness and thickness of the thin film. The adhesion property of these metal thin films was estimated by measuring the pull strength. Aluminum thin film showed highest pull strength of all the thin films, and the pull strength increased with increase of the thickness.

抄録全体を表示

  The electrical characteristics of TaAl-N thin films prepared by radio frequency (RF) superimposed and direct current (DC) reactive sputtering method was investigated. The properties of TaAl-N thin films were strongly influenced by the sputtering method. In the condition of Rn=30% [Rn=F(N2)/(F(N2)+F(Ar))], total pressure 0.3 Pa, the resistivity (at RT) was 3.1 Ωcm and the TCR (at 150°C) (the temperature coefficient of the resistivity) was (-) 13000 ppm/°C. The stresses of TaAl-N thin films were relieved.

抄録全体を表示

  We investigated surface morphologies of Ni thin films evaporated on polyethylene naphtalate (PEN) organic substrates for the fabrication of spin quantum cross structures and discussed its feasibility toward ferromagnetic nanojunctions from a viewpoint of the Ni grain size and the Ni surface roughness. The grain size for Ni films of sub-10-nm thickness is ~30 nm, which is larger than the Ni thickness, and the surface roughness, in the scanning scale of the film thickness, is less than 0.25 nm, corresponding to one-atomic-layer thickness. These experimental results indicate that spin quantum cross structures which consist of Ni thin films on PEN substrates can be expected as a candidate of ferromagnetic nanojunctions, which may lead to large magnetoresistance effect.

抄録全体を表示

  The generation of a carbon nanoparticle was investigated in an electric arc discharge using a carbon electrode containing silicon and oxygen while being irradiated with ultraviolet rays. It was found that a small number of nanoparticles were generated with the arc, but a dramatic increase in numbers was observed with ultraviolet radiation. The compression strength of the nanoparticles was measured to determine the possibility of their use as a reinforcing material in composite materials. The compression strength of a large particle that was an amorphous compound not having a crystal structure was not very high. On the other hand, a small nanoparticle having a crystal structure did not collapse, even for an applied compression stress of 50000 N. Thus, these nanoparticles are promising as a reinforcing material in particulate composite materials.

抄録全体を表示

  Implantation of In into SiO₂ thin film substrates by mono-energetic In ion beams was examined with the use of a low-energy mass selected ion beam system. The goal of this study is to develop thin film based In-Si combined catalyzer for organic chemical reactions. In the experiments, In ions were generated by sputtering of an In₂O₃ target by Ar ions in a Freeman-type ion source and extracted to form, after mass selection, a mono-energetic beam with the peak energy of 470 eV. The ion beam was then injected into SiO₂ thin films formed on Si substrates. By X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and atomic force microscopy (AFM) measurements, it was found that In nano particles were formed on the SiO₂ thin film surface after the beam injections and the shapes of the particles varied depending on In ion dose.

抄録全体を表示

  The highly concentrated (almost 100 vol.%) ozone gas has been utilized to dry oxidation of SiC single crystal substrates by using a quartz furnace with local heating by a halogen heater. When the flow velocity of ozone was kept as high as 5 m•cm^-1 or more, the strong oxidizing power of ozone enabled rapid oxidation of SiC at a considerably lower temperature than that for the oxidation in oxygen. The ozone oxidation also resulted in a lower interface state density in the device charactrization for the MOS structure probably because the ozone oxidation was effective in reducing carbon-related defects.

抄録全体を表示

  Fourier-Transformed Infrared absorption spectroscopy (FT-IR) was applied to analysis of initial photochemical reaction of ozone (O₃) and 1,1,1,3,3,3-hexamethyldisilazane (HMDS) at room temperature in the gas phase under the irradiation of an ultraviolet (UV) light, as the side reaction during the fabrication of a silicon oxide (SiO₂) film by photo-assisted chemical vapor deposition (CVD). FT-IR spectrum indicated the photodissociation of O₃ by the UV light, shown by the decreases in the intensity of peaks assigned to an O₃ molecule in the spectrum. Under the confirmation of this photodissociation of an O₃ molecule, while the UV light is known to induce no photochemical reaction of HMDS, FT-IR spectrum indicated the photochemical reaction of HMDS by its scission of Si-N-Si bond and formation of C=O bond and SiO₂ in a mixture of O₃ and HMDS gases, thus showing that direct reaction of photodissociated species from O₃, possibly atomic oxygen, with HMDS.

抄録全体を表示

  We have oxidized Si wafer at lower than 200°C using an electronically excited oxygen atom that is generated by the irradiation of UV light to low pressure highly concentrated ozone gas. We used high-pressure mercury lamp, as the light source because it has a strong emission between 210 nm and 300 nm by which ozone is effectively absorbed and photo-excited. SiO₂ film formation with its thickness fluctuation of less than 0.2 nm within light-irradiated area has been easily achieved as long as the intensity of the light irradiated to low-pressure ozone is uniform within 10 percent. The SiO₂ film thickness is 3.3-4.1 nm at 200°C for 10 min on the 8″Si(100) wafer. By the sample rotation during oxidation process, we could oxidize the SiO₂ film homogeneously on the 8″ wafer.
  This film can be applied to a buffer layer between deposited film and poly-Si substrate of the gate dielectric film of the low temperature poly-Si thin film transistor.

抄録全体を表示