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Chromium nitride (CrN) thin films were fabricated onto Si wafers by RF magnetron sputtering equipment in pure N2 gas. By adjusting the fabrication conditions, the film had negative temperature coefficient of resistance (TCR) below 300 K. It showed reasonable sensitivity between 300 and 1.8 K. The temperature resolution in the cryogenic temperature region was better than 1 mK. A good thermal cycle stability was observed. After 27 thermal cycles between 4 and 300 K, the coefficient of variation (CV) value was as small as 0.098% at 4 K, which corresponds to a 2.1 mK temperature shift. In addition, the thermometer was nearly insensitive to the magnetic field. The temperature shift due to magnetoresistance in a magnetic field of 9 T was less than 5 mK at 4 and 2 K. Therefore CrN can be an excellent choice of material for cryogenic temperature sensors under magnetic fields.

A CuScO 2 (0 0 0 1) epitaxial film with a thickness of a few hundred nanometers was successfully grown on an a -plane sapphire substrate by combining the two-step deposition and post-annealing techniques. The film was single-phase with a rhombohedral crystal structure and showed six-fold rotational symmetry in the basal plane, indicating that the film had a twinned domain structure. The orientation relationships of the film with respect to the substrate were CuScO 2 [3R](0 0 0 1)//sapphire(1 1 2¯ 0) and CuScO 2 [3R][1 1 2¯ 0]//sapphire[0 0 0 1]. The average optical transmittance of the film was higher than 60% in the visible/near-infrared regions, and the energy gap for direct allowed transition was estimated to be 3.7 eV. The p-type conduction of the film was confirmed by Hall measurement. The electrical conductivity, carrier concentration, Hall mobility, and Seebeck coefficient of the film at room temperature were 1.0×10 −3 S cm −1 , 4.5×10 16 cm −3 , 1.4×10 −1 cm 2 V −1 s −1 , and +968 μV K −1 , respectively. The activation energy estimated from the temperature dependence of the carrier concentration was 0.62 eV.

Aluminum-doped ZnO–SnO2 (ZTO) films were deposited by RF magnetron sputtering using a Zn2SnO4 target at 400 °C under Ar gas pressure of 2.0 Pa. The Al doping was carried out by placing Al sheets on the Zn2SnO4 target and the inclusion of Al was observed to increase to 5.3 at.%. The transmittance of Al-doped ZTO films decreased in the short wavelength region with increasing Al concentration. Al doping had no observable effect on the refractive index, but the electrical properties were remarkably affected. The conductivity exponentially decreased from 3.2 × 10 to 2.3 × 10− 4 S cm− 1 as the Al concentration increased from 0.0 to 5.3 at.%. The Hall mobility and free carrier density also decreased with increasing Al concentration.

A CuScO 2 (0001) epitaxial film with an oxygen intercalation layer was formed by annealing using oxygen radicals, and the electrical and optical properties of the epitaxial film were investigated. The thickness of the layer was 60 nm from the film surface, and its electrical conductivity was analyzed by using the two-layer model. The dependence on temperature of the electrical conductivity and Seebeck coefficient revealed that the dominant conduction mechanism of the layer was a small polaron conduction above 150 K and that it changed to two-dimensional variable-range hopping conduction below 150 K. The optical average transmittance of the epitaxial film was larger than 65% in the visible/near-infrared regions, while the energy gap for direct allowed transition was estimated as 3.7 eV.

We fabricated a CuScO2 thin film on an α-Al2O3 (1 1 2 0) substrate by the pulsed laser deposition method using a single-phase Cu2Sc2O5 target, and investigated the effect of oxygen pressure on the film quality. Under optimized oxygen pressure, we obtained a single-phase CuScO2 thin film whose crystalline structure was the rhombohedral system. The film showed a strong c-axis orientation. The optical transmittance of the film was greater than 70% in the visible/near-infrared region, while the energy gap for direct allowed transition was estimated to be 3.7 eV. The resistivity (ρ) was 8.6×103 Ω cm at room temperature, and log ρ was proportional to T−1/4 below 250 K. This suggests that a variable-range hopping mechanism is dominant below 250 K.

This paper describes a proximity correction for fabricating a chirped diffraction grating by direct-writing electron-beam lithography. The electron dose distribution is optimized by calculation with an electron-scatter simulator and a resist development simulator. These simulators are based on the Monte Carlo method and a cell removal model, respectively. To avoid an excessive increase in calculation time, the calculation was performed with 100 nm×100 nm square cells at an accuracy larger than that desired. Also, the resist profile was estimated accurately by adopting the interpolation with the resultant cell profile. In the case of a chirped period grating of 5 mm in width, it took 24 h to calculate the optimum electron dose profile. Moreover to investigate the validity of this correction method a chirped period grating of 0.1 mm in width was fabricated with the calculated dose profile.

The deep gratings with ultrahigh spatial frequencies have been developed for wavelength dispersion applications. The diffraction performances, including diffraction efficiencies, wavelength dispersive abilities and wavelength band, have been theoretically investigated. The high diffraction efficiencies, wide wavelength dispersive abilities and broad wavelength range proved the significant advantages of the developed gratings for our applications. For the fabrication process, a method for synthesizing the grating profiles to produce optimal optical performances for practical applications and for easily achieving high fidelity by microfabrication technologies has been proposed. The experimental results show that the fabricated gratings using the synthesis method have diffraction efficiencies higher than 95%, while the wide wavelength dispersions are reserved, and low diffraction fluctuations are also reduced.

Electron beam lithography is a highly flexible method that can be used to fabricate diffractive optical elements. However, the long exposure time required is the most serious point that needs addressing, and this is derived from the lack of sensitivity of the electron beam resist. We have investigated the physical properties of polydimethylsiloxane and poly(dimethylsiloxane-co-methylvinylsiloxane) for electron beam lithography. The results show that these polysiloxanes exhibit much higher sensitivities than the conventional substances, of 1.5 and 0.9 µC/cm2, respectively, and that they have a γ value of 1.3. Using these polysiloxanes, we succeeded in fabricating a four-level phase computer-generated hologram.

Electron beam lithography is a highly flexible method to fabricate micro-optical elements. However, the long exposure time is the largest problem, which derived from the lack of the sensitivity in electron beam resist. Instead of conventional carbon-based resists, physical properties of polydimethylsiloxane (PDMS) and poly [dimethylsiloxaneco-methylvinylsiloxane] (PMVS) for electron beam were investigated. As a result, these polysiloxanes exhibited a much higher sensitivity of 1.5 and 0.9μC/cm2, respectively and adequate γ value of 1.3. We succeeded in fabricating a four-level computer generated hologram on a glass substrate with ITO film using PMVS in 1/10 exposure time compared with conventional resists.

A LiNbO3 thin film was successfully fabricated onto a sapphire (001) substrate using pulsed laser deposition. The film quality was largely affected by substrate temperature, oxygen gas pressure, laser fluence and laser repetition frequency. By adjusting these conditions, a highly c-axis oriented LiNbO3 film was obtained. The ordinary refractive index of the film became 2.28 at 632.8 nm of wavelength, which coincided with that of a LiNbO3 single crystal. RHEED observation showed the film had twin boundaries. Further improvements are now undergoing.

An epitaxial film of La0.7Ca0.3MnO3 has been successfully fabricated by pulsed laser deposition. The film shows a phase transition from paramagnetism to ferromagnetism at around 190 K with a steep resistance change. This resistance change can be used for a bolometric photosensor and results in detectivity D*, noise equivalent power (NEP) becomes D* = 2.7×108 cm √Hz W−1 and NEP/√B = 7.4×10−10 W √Hz, where B is the band width of an amplifier and is assumed to be 1 Hz.

A thin film thermometer using sputtered zirconium nitride has been investigated as a low-temperature thermometer. This film deposited on a sapphire substrate can be used to measure a wide temperature range from 1 to 300 K with reasonable sensitivity within a fast response time. The thermometer sensitivity can be altered by changing fabrication conditions. Moreover, the thermometer is almost insensitive to magnetic fields. The temperature error in a magnetic field of 6 T is less than 10 mK at 4.2 K.

A conventional method to synthesize diffractive optical elements and computer-generated holograms (CGH’s) with high diffraction efficiency relies on an increase of phase levels. To fabricate such a device, one should perform electron-beam (e-beam) lithography with multiple-dose exposures or multiple-step photolithography. Here we describe a one-step method, which is based on the effective medium theory, for the fabrication of a multilevel phase CGH. The phase modulations required in cells of a CGH are constructed by means of dividing these cells into fine (subwavelength) structures. The surface features of these fine structures control their corresponding indices, and their values can be calculated according to the effective medium theory. By proper selection of the fine structures, based on the requirements of the phase modulation of the cells, a CGH with multilevel phases is synthesized when a binary structure is relieved on the dielectric material. Then the CGH can be fabricated by direct e-beam lithography or one-step photolithography through an amplitude mask followed by an ion-etching treatment. The experimental results showed that the reconstructed wave field is in good agreement with that simulated by a computer, indicating the effectiveness of the proposed method.

We propose a new design method for periodic diffraction gratings to be fabricated with direct-writing electron-beam lithography. When the grating has a small period, the proximity effect of electron scattering restricts the grating profile after developing. Our design method optimizes the electron-dose profile and grating profile simultaneously to obtain the desired diffraction efficiency under the restriction of the proximity effect. The optimization is made with rigorous electromagnetic grating analysis and the resist development simulator. When we designed the diffraction grating with a period of 1.0 microm to obtain the highest efficiency of the first-order diffracted light of a 633-nm wavelength, the calculated grating profile was really different from the profile optimized only with rigorous electromagnetic grating analysis. Moreover, the diffraction grating of the electron-beam resist was fabricated according to the simulation result. The estimated diffraction efficiency was 82%, and the measured efficiency was 70%.

Polarization-multiplexed phase-only diffractive optical elements with subwavelength structures are proposed and fabricated. The differences among the phase modulations result from the differences among the effective indices exhibited in the subwavelength structures with various filling factors and surface profiles, and the phase retardations are obtained by the relief depth of the structures. The polarization-selective property is achieved by the polarization dependence of the effective indices exhibited in the one-dimensional subwavelength structures and the polarization independence exhibited in the two-dimensional structures. Additionally, the polarization contrast of our polarization-multiplexed elements, defined as the cross talk between the two polarization incidences, is independent of the relief depth. The principle of the polarization multiplexing by use of the subwavelength structures is described, and the fabrication results for the polarization-multiplexed computer-generated holograms are demonstrated.

We have developed a new design method of periodic diffraction gratings to be fabricated with the direct-writing electron-beam lithography. The grating profile is optimized by the rigorous electromagnetic grating analysis and the proximity correction of electron scattering. When the grating has a small period, the proximity effect of the electron scattering restricts the grating profile. Our design method optimizes the grating profile under this restriction. For the period smaller than 2µm, the designed profile differs much from a profile optimized only by the grating analysis. The diffraction efficiency is reduced slightly, but the designed profile eases the fabrication with the electron-beam lithography.

Spectroscopic imaging is useful technique in applications such as coloring-matter identification in old paintings or textiles, chemical-state analysis in biological or medical diagnosis, etc. An optical system, in which two-dimen- sional images for different wavelengths are taken in turn by using wavelength filters, is not good at detection of continuous spectra. Another system, where wavelength of light source is scanned, can not be applied for luminescence or wavelength-shift case. Fourier transform spectroscopic imaging technique requires complex optics and data conver- sion. On the other hand, a compact and handy system is strongly desired in application to in situ analysis or in vivo diagnosis. A thin film grating lens1−4) is very attractive in system miniaturization since wavelength dispersion function and lens function can be achieved by a single component. Besides it, the grating can be fabricated by using planar fabrication processes with high productivity. However, a grating lens is not good at wide-view-angle imaging, because large aberration arises when the grating is used with neither designed incident wavefront nor designed wavelength. Specially designed systems5, 6) are therefore required for suppressing aberration down to practical level. In this paper, we discuss a new compact optical device capable of two-dimensional mapping of continuous spectra, and report the fabrication and experimental results of the grating lens.

A new type of hybrid magneto-temperature sensor has been fabricated on the surface of YBa 2 Cu 3 O 7 - δ (YBCO) ceramics by creating two types of electrical contacts. The type 1 contact, made by the ultrasonic bonding method, showed nonlinearity below the superconducting critical temperature ( T c ) in its current-voltage (I – V) curve, which was sensitive to the magnetic field. This was applicable as a strict magneto sensor. The type 2 contact was made by the spot-welding method and showed non-ohmic contact in its I – V curve, and was not affected by the magnetic field at all. This was applicable as a strict temperature sensor. Integration of these two types of electrical contacts on YBCO ceramics make an excellent and simple hybrid magneto-temperature sensor device. The features of this sensor are: simple structure and simple fabrication process: very small size; high sensitivity to a low magnetic field; and simple integration of magneto sensor and temperature sensors.

The electrical properties of chrome nitride (Cr–N) films have been investigated for application to cryogenic temperature sensors. The films were deposited on silica substrates by RF magnetron sputtering under various total pressures without substrate heating. The electrical resistivity at room temperature increased from 1.4×10-3–1.7×10-3 to 3.4×10-3–4.0×10-3 Ω cm as the total pressure increased. X-ray diffraction measurements revealed that the crystallinity was improved in the high-total-pressure region. The temperature dependence of the electrical resistivity for Cr–N films exhibited semiconducting behavior. The slope of the electrical resistivity versus temperature increased with increasing total pressure. When a magnetic field was applied parallel to the current direction, the change in magnetoresistance at 3.7 K for Cr–N films was less than 1% in the range of 0 to 10 T. The results indicated that temperature sensors made of Cr–N films are available in high magnetic fields.

A zirconium nitride(Zr-N) thin film for cryogenic thermometer was fabricated by using a reactive rf-sputtering equipment. The Zr-N was deposited on a sapphire or a glass substrate. The composition ratio ofthe film could be changed by changing the sputtering condition such as partial pressure of N2. The Zr-N film, which had excess nitrogen(N>Zr), showed negative TCR (Temperature Coefficient of Resistance) and was classified into three groups by its RR (R4.2K/R300K) and MR (magnetoresistance). The group I (RR

Our aim of study has been to realize a superconducting YBCO thin film growth on versatile substrate such as stainless steel, Si wafer or glass substrate by reducing the substrate temperature. In order to realize above purpose, we have developed a three source electron beam evaporation system, in which pure metal sources were adopted. Oxygen radicals exited by an RF multi-capillary ion source were irradiated onto the substrate during deposition. Even though the metal composition of each film was off-stoichiometry(Y:Ba:Cu=l: 1.6:3.7), the Tco of YBCO thin film were 72 K for MgO substrate, 63 K for SUS304 sheet, 64 K for glass substrate, respectively. The reaction between YBCO and each substrate was significantly reduced by means of relatively low substrate temperature of 565 °C. The improvement of Tc will be made by adjusting the film composition and deposition conditions.

The lead added BiSrCaCuO thin film of high-Tc phase has been successfully prepared by using rf-magnetron sputtering and post annealing process. The content of lead in the thin film was easily decreased during the ordinary annealing process. In order to minimize the decrease of lead, the Pb-doped BSCCO thin film was placed on the bulk ceramics and annealed for over 170 hours at 855°C in air. As the result, the content of Pb was almost unchanged and the film showed superconducting transition at 104 K.

Index-guided two-dimensional (2D) optical waveguides are numerically studied to investigate propagation properties of guided optical waves. The 2D optical waveguide consists of a dielectric thin film sandwiched between two semi-infinite metals. We demonstrate that vertically localized 2D optical waves can be laterally confined and guided by index guiding when the dielectric film has a high-refractive-index core and claddings of a lower index. The index guiding provides good optical power transmittance, otherwise optical power is rapidly attenuated due to lateral beam divergence.

An epitaxial film of CuScO2, a transparent oxide semiconductor with a delafossite structure, was grown on an α−Al2O3(112¯0) substrate by a pulsed laser deposition method using a single-phase Cu2Sc2Oδ target. A two-dimensional x-ray reciprocal space mapping measurement revealed that the film was single phase with a rhombohedral crystal structure. The film showed six-fold rotational symmetry in the basal plane, indicating that the film had a twinned domain structure. The epitaxial growth of CuScO2[3R](0001) thin films on α−Al2O3(112¯0) substrates is caused by the uniaxial locked epitaxy mechanism along the ⟨1¯21¯0⟩ direction of the film, and the orientation relationships of the film with respect to the substrate were CuScO2[3R](0001)∕∕α−Al2O3(112¯0) and CuScO2[3R][1¯21¯0]∕∕α−Al2O3[88¯01]. The optical transmittance of the film was larger than 65% in the visible/near-infrared regions, while the energy gap for direct allowed transition was estimated as 3.7 eV. The resistivity of the film, 9.3×106Ωcm at room temperature, significantly decreased to 4.0 Ωcm after both substituting Mg2+ ions for Sc3+ and intercalating excess oxygen. The Mg-doped CuScO2+X(0001) thin film showed optical transmittance of larger than 65% in the visible region, and the Seebeck coefficient was positive, indicating a p-type conductivity.

Zinc stannate (Zn2SnO4) thin films were deposited by RF magnetron sputtering on silica substrates at various [O2/(Ar+O2)] flow ratios. The influences of the [O2/(Ar+O2)] flow ratio on the crystalline structure, and the optical and electrical properties have been investigated. No sharp X-ray diffraction (XRD) peaks were observed in as-deposited thin films. After postdeposition annealing in air at 750°C, the thin films showed a preferred orientation of (111). The thin films exhibited a high transmittance in the visible spectrum irrespective of the [O2/(Ar+O2)] flow ratio or postdeposition annealing. The optical band gap was estimated to be 4.1 eV by analyzing the optical spectra of thin films annealed at 750°C. The composition ratio of Zn/Sn for thin films deposited in an Ar/O2 mixture was 2.0 and their electrical resistivity was on the order of 105 Ω·cm. In contrast, the composition ratio of Zn/Sn for a thin film deposited in pure Ar was 1.5 and an electrical resistivity of 4.1 ×10-2 Ω·cm was observed.

The form-birefringence effect exhibited in the multilayered subwavelength structure (SWS) has been applied for the realization of wave plates. The SWS was obtained by coating a thin film of a material with a high refractive index onto a base SWS fabricated on a substrate with low refractive index. The multilayer SWS fabricated by this coating process exhibits strong form birefringence compared with that of the base SWS. This fact results in less depth required to realize wave plates than that with only the base SWS. In this study, a quarter-wave plate for the operating wavelength of a He-Ne laser (λ= 632.8 nm) was designed and fabricated using the above described multilayered SWS. The experimental results demonstrated that the fabricated device is effective as a quarter-wave plate and gives transmission efficiencies near 90% for both transverse electric (TE) and transverse magnetic (TM) waves.

A compact spectroscopic imaging device consisting of a planar reflection grating lens, a probe fiber array, and a two-dimensional image sensor was proposed and discussed. Reflected or luminescent lights from a subject are coupled to the probe fibers, guided to fiber output ends, radiated into the air, diffracted by the grating lens with wavelength-dependent angle, and focused onto lines on the image sensor. Two-dimensional intensity distribution on the image sensor can give one-dimensional spectrum distribution along a specified direction. A grating lens was designed with a fiber array and a CCD image sensor for 100-nm wavelength range and 10-mm fiber array width. A spectral resolution of 5 nm and a spatial resolution of 0.25 mm were experimentally confirmed.

Zr-N films in the variable-range-hopping regions show an oscillatory magnetoresistance (MR). MR consists of a linear negative MR (LNMR) below 1.5T, a positive one above 1.5T and again a negative MR in higher field. We investigated the origin of LNMR. The LNMR of Zr-N films can be quantitatively interpreted by a quantum coherence effect that is characteristically seen in VRH regime.

An antireflection surface with sub-wavelength structure has been successfully fabricated on a fused silica substrate. The fabricated antireflection structured surface consists of a microcone array of fused silica with a period shorter than the wavelengths of visible light. The microcone array is made by a reactive ion etching method using fluorocarbon plasma. A microdisk array of chromium thin film, formed by an electron-beam lithography and lift-off process, is used as the etching mask. Since an electric field induced near the substrate was focused on the edges of the metal disks, these disks gradually shrank. Consequently, a conical shape was formed. The fabricated cone array has a period of 250 nm and a height of 750 nm. Measured reflectivity of the antireflection structured surface is less than 0.5% in the wavelength range of 400–800 nm for normal incidence.

Ohmic contacts on (Bi, Pb)-Sr-Ca-Cu-O (BSCCO) superconductor ceramics have been studied. When the electrodes were formed on the as-sintered surface of a BSCCO pellet, nonohmic characteristics were observed. Analysis by X-ray photoelectron spectroscopy suggests that the surface layer of the BSCCO pellet is degraded. When the fractured section of a BSCCO pellet was used, both Cu and Ag electrodes were found to be ohmic without thermal annealing.

Thin Zr-N films have been prepared by reactive RF magnetron sputtering. The nitrogen partial pressure and the RF power are chosen as sputtering parameters. The relationships between film properties, such as composition, structure, optical and electrical properties, and these sputtering parameters is systematically investigated. The relationships between the nitrogen pressure and the RF power for each property of Zr-N films in the sputtering process are also discussed. It is found that the film properties can be widely changed by controlling RF power as well as nitrogen pressure. A semiconductorlike Zr-N film is obtained with sputtering in the high-nitrogen-pressure region. The conductance of the semiconductorlike Zr-N films changes with temperature, conforming to a function of exp (E/kT) in the temperature range from 200°C to 550^°C, w h i c h i s a p p l i c a b l e t o a t h e r m i s t o r.

Temperature and magnetic field dependence of the resistivity of Zr-N sputtered films have been measured. The characteristics of Zr-N film, that they can be divided into two groups by the ratio of the resistance at helium and room temperatures, have been precisely investigated. There are marked differences in both the temperature dependence of resistance and in the magnetoresistance between the two groups. The temperature dependence of magnetoresistance of the films has been discussed within the framework of Anderson localization. The origin of magnetoresistance was also discussed.

The photoresponse of YBa2Cu3O7-d thin film with double bridges (DC-SQUID type) has been investigated under irradiation of weak laser light. The YBCO thin film of 200 nm thickness was prepared on a MgO(100) single-crystal substrate by an rf-magnetron sputtering method. It was processed to perform as a double microbridge (DC-SQUID type) patterned by ECR ion etching and then assembled as an YBCO thin-film sensor. The microbridge used here was 5 µm in width and 7.5 µm in length. The sensitivity of the sensor was determined by irradiating a modulated laser light (modulating frequency of 17 to 400 Hz, wavelength of 827 nm). The device showed both bolometric and nonbolometric behavior in the superconducting transition region. The maximum noise equivalent power (NEP) and responsivity was obtained at 76 K, and was 5×10-9 W/Hz1/2 and 19 V/W, respectively. The nonbolometric response was caused by vortex motion.

Thin films of Zr–N have been prepared by reactive ion beam sputtering. The relation between film properties, such as structural, optical and electrical properties, and nitrogen gas pressure and ion beam is systematically investigated. The film properties can be controlled not only by varying reactive gas pressure, nitrogen gas pressure, but also by varying sputtering ion beam current even at a constant nitrogen gas pressure. The previously proposed model of a reactive sputtering mechanism for the Zr–O system, which takes into account the gettering action of Zr atoms and deals with the number of sputtered Zr atoms and O2 molecules, is expanded to a sputtering mechanism for the Zr–N system and discussed quantitatively. The nitrogen partial pressures during sputtering calculated from the expanded model are compared with experimental results. It is found that the calculated values agree well with the experimental results.

The effect of ion irradiation on ZnO thin film's crystal orientation during dual ion beam sputtering deposition is studied. Glass and Si substrates are irradiated during depostion by oxygen and argon ions. The irradiating oxygen ions are swept away from the substrate by a cross-electric field to examine the effect of high energy neutral atoms on crystal orientation. Argon and oxygen positive ions prepared in a saddle field ion gun can effectively form c -axis orientation in ZnO film deposition. But oxygen high energy neutral atoms tend to deform the c -axis orientation of the films. ZnO film prepared by this method is useful in the production of devices with good piezoelectric and pyroelectric properties.

Zinc oxide films have been prepared by ion beam sputtering deposition. The irradiation effects of the charged particles on the ZnO film crystallographic orientation during deposition are studied. Two methods are adopted to control the bombardment of the charged particles. One applies a bias voltage to the substrate, and the other bombards the substrate with ions. When the substrate is positively biased, the c-axis preferred orientation of the ZnO film is destroyed by the negatively charged particles. When the substrate is negatively biased, or irradiated with argon ions from a side ion gun, certain conditions lead to c-axis orientation. When the substrate is irradiated with oxygen ions, a change to c-axis orientation can clearly be observed. Positive oxygen ion irradiation presumably has an effect on the formation of ZnO film c-axis orientation.

The effects of charged sputtered particles on the crystal orientation during ion beam sputtering deposition of zinc oxide films are presented. The formation of the necessary c -axis orientation was tried by controlling the kinetic energies of the sputtered charged particles in two different methods. In one method, a bias voltage is applied to three substrate materials: Corning 7059 glass, Si(100), and ZnS thin film, while in the other method, it is applied to a ZnO target. It is found that the existence of positively charged sputtered particles and the absence of negatively charged particles on the substrate are effective in forming c -axis orientation.