Double layer dielectric films are examined for Si surface passivation in a radiation hardened Si device. The double layer dielectric films of Si3N4/SiO2 and PSG/SiO2 are shown to have lower sensitivity to ionizing radiation than a CVD-SiO2/SiO2 film named a double layer SiO2 film. However, the former two dielectric films show much larger initial interface state densities than the latter one. Effects of post oxidation annealing on the radiation induced interface states are also studied. The double layer SiO2 film is applied to realize an IIL device with a radiation tolerance of more than one Mrad(Si).
Abstract Recently, a need has arisen for an economical untrimmed 14 ‐ 16‐bit D/A converter in the field of digital audio and precision metrological systems. However, the precision of the monolithic D/A converter is about 10 bits to date, which can be improved to 12 ‐ 13 bits by applying a special trim technique. In order to obtain the required high‐precision converter, a self‐correcting equation is established to treat the error involved. The result—a monolithic IC—has been studied experimentally. For the most part, this paper discusses the circuit structure and the test results of the monolithic 14‐bit, DAC developed on the basis of this self‐correcting equation. The monolithic DAC was prepared by combining the type I 2 L digital analog process and the two‐layer microwiring technique and exhibited a linearity of ±1/2 LSB (±0.003%) and a setting time of 1.2 μsec.
The large hall of the Tokyo Geijutsu Bunks-Kaikan is planned as a concert hall for classical music with 1887 seats. At the first stage of the design, the room shape and seating arrangements proposed by the architect were studied by computer simulation, in which the energy distribution of the early reflections over the seating area was observed. The room shape was repeatedly studied and re-designed considering the architectural design policy and acoustical characteristics. At the final stage of the design, a ray experiment in a 1/50 scale model was introduced. Acoustical experiments in a 1/10 scale model are planned in order to predict the room acoustical parameters and to check on detrimental echoes. The room acoustical design policy and the details of the new auditorium will be presented.
Organ music is not common in Japan, which has a poor church-music tradition. Almost all organ concerts are performed in concert halls. This is a major difference from the situation in North America and European countries. Concert halls in Japan are therefore generally expected to also serve as organ recital halls. In order to fulfill the requirements of both concert halls for classical music in general, and organ recital halls in particular, several ideas and devices have been developed and introduced such as movable reflectors, ceilings, partitions, and a reverberation enhancing system using digital signal processing (DSP). The presentation will explain these measures and their effects on the listening experience and discuss the problems involved in carrying out such design work.
The orchestra riser system has been installed in the Kyoto Concert Hall, which was newly opened in the autumn of 1995. This paper introduces the design process of the stage riser system and its floor structure in detail. The orchestra, including string sections, could be arranged in a three-dimensional manner with this riser system. Its drastic effect on the acoustics of the hall was confirmed at actual rehearsals and concerts in Suntory Hall. The form, division size, and height of each riser element were discussed with the resident of the hall, Kyoto Symphony Orchestra, using the riser mockup. The extent of the orchestra became more compact for the 3-D arrangement than that for flat one. The stage floor structure was selected through audition of 14 floor samples on which strings and a timpani were played. The samples contained four timber materials of several different thicknesses, and with or without an underneath layer. Some listeners preferred floors that resounded with fullness, but others preferred different floors that resounded tightly and clearly. Finally, a 40-mm Hinoki cypress without an underneath layer was selected as the stage floor structure.
