Photoirradiation results in distinct changes in chemical properties of chalcogenide glass films. These photochemical effects can be utilized to realize a photoresist using an inorganic material. In this paper, fundamental characteristics and features of the inorganic photoresist, as well as its processings, are presented. It is shown that Ag-photodoping effect, which brings about the remarkable difference in the chemical solubility of chalcogenide glass films, gives an excellent performance in photoresist application. The binary system of Se-Ge is singled out as a suitable chalcogenide. Compared with the conventional organic polymer resist, the inorganic resist has many attractive and advantageous features in its high resolution capability, dry-processing nature, electron-beam sensitivity with extremely high contrast and other advan-tageous material properties. A variety of applications are also promising. The study of inorganic resists is a topic of interest in the resist researchers. Continuous efforts are now being performed, aiming at their practical use.
ZnO thin films were formed by a reactive RF magnetron sputtering technique. A study was made on the influence of sputtering gas pressure and substrate temperature on the c-axis orientation and surface morphology of ZnO thin film under the condition of constant deposi-tion rate. Concerning the surface morphology and the substrate temperature dependence of the c-axis orientattion, a difference was found between the ZnO thin films formed below the sputtering gas pressure of 7×10-2 Torr and those formed above the pressure of 7×10-2 Torr. It is difficult to form the normally c-axis oriented ZnO thin film below 7×10-2 Torr.
Discrete Josephson transmission lines based upon proximity effect bridges have been made by photoresist and anodization techniques. They are composed of 2-9 weak links conected in parallel. Several peaks and steplike structures occur in their differential resistance-current (dV/dI-I) characteristics. It was discussed in a Stewart-McCumber equivalent circuit by means of numerical analysis. The quantum interference properties of these lines are found both in critical current-applied magnetic field (Ic-H) characteristics and in dV/dH-H characteristics at constant applied current. The observed periodicities in both characteristics are in very good agreement. Over a certain range of temperatures, quantum-interference patterns similar to the N-slit diffraction patterns in optics were obtained for these lines containing N weak links, indi-cating that all of the weak links contained in these lines were operating. The velocities of the flux flow in these transmission lines were obtained from voltage-applied magnetic field (V-H) characteristics.
Structure of SiO films deposited at an angle of incidence of 60 has been investigated with a transmission electron microscope (TEM). Structure of these films are estimated from the density of TEM photographs. No columnar-growth structure has been observed on these films. Elastic strain energy in a bulk of a nematic liquid crystal is calculated from a Fourier analysis of the structure of the SiO film. Minimum energy is obtained when liquid crystal molecules align themselves perpendicular to the evaporation direction. Components of surface roughness having wavelength of several tens of angstorm make the dominant contribution to the strain energy.
A large-scale laser radar system, which measures Mie scatter from atmospheric aerosols and Raman scatter from major atmospheric components, has been constructed to observe the pollution over a wide area. For the system design, a laser wavelength should be selected carefully in order to observe the wide range, and from the numerical calculation, the Nd: YAG laser and its second harmonic were found the best. The major specifications of the system are as follows: laser output of 30W (at 1.06μm) and 10W (at 532nm) with a repetition rate of 25pps and pulse duration of about 15nsec, and 1.5m for the effective diameter of the receiving telescope. The SIN ratio was calculated and the observable range was found to be 50 to 60km for Mie scattering. This calculated range was verified by field observation.
The emission mechanisms of the secondary electrons by ion bombardment are described for the high accelerating voltage region and the intermediate and low accelerating voltage region. The former is explained by the Sternglass's theory; the last is by the Parilis and Kishinevskii's theory, inner Auger process. The distinctive characteristics of the secondary electron emission from an insulator by ion bombardment is the generation of surface potential caused by the positive holes due to ion bombardment. The typical influence on the secondary electron emission due to the surface potential is broader energy distribution than that in not charged surface. The bulk conduction becomes dominant rather than the surface conduction in SiO as the accelerating voltage of the ion implantation increases. The conduction mechanism for both surface and bulk conduction are interpreted by the continuous-time random-walk model (CTRW) that positive holes travel by tunneling the trap levels.
This review has summerized the development of pyroelectric infrared sensors from the previous one (1974). While families of TGS, PZT and PVF2 were studied to improve the performance, the detectivity of the single sensors at low frequencies became within an order of the theoretical limit, and those using refractory meterials, such as LiTaO3 and PdTiO3, are now commercially available. As uncooled infrared imaging device there has been steady development of the pyroelectric vidicon for tube life and spatial resolution, especially the latter being improved with the reticulated target. Solid state imaging device with CCD read-out looks to become usable in near future.
In order to determine the fast response capability of the photoconductive detectors of semiconductors, the recombination life time of the electrons which were excited from the impurity states to the conduction band by the far-infrared radiation has been discussed. In conclusion, the Ge photoconductive detectors are confirmed to be available to observe modulated radiation up to frequency as high as a few GHz. The video response and the heterodyne response have been defined. The definitions give the relation between the noise equivalent power of the video receiver NEPz and that of the heterodyne receiver NEPh. The brief descriptions are given of the photoconductive detectors at the wavelength region 20μm to 1mm and also of those at 10μm with high frequency modulation capability in the frequency region 400 MHz to 5 GHz.
Progress in laser frequency stabilization has made it possible to reproduce the wavelength of an optical transition with an accuracy of better than the present standard of length. Since the technique of laser frequency measurement has now been extended into the visible, the metre can and will be redefined in terms of the adopted value of the speed of light. Several proposals of redefining the metre are being considered by the sub-committees of the Interna-tional Committee on Weights and Measures.