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Novel Optical Proximity Correction (OPC) flow using the new compact lithography model which predicts wafer patterns formed by the trim-mask lithography has been developed. The trim-mask lithography has been indispensable to manufacture the random-logic devices using the leading-edge processes which require double patterning technology (DPT) and/or restricted/reduced design rule (RDR). It is the litho-etch-litho-etch (LELE) DPT in which a trim process, a litho-etch (LE) process, follows one or several LE processes. The trim process is used to remove redundant patterns in order to achieve the final patterns corresponding to design intent after forming periodic and lithography-friendly patterns by the preceding LE processes. In addition, it is used to form the narrow gaps between line ends 1 . Since the influence of both the preceding processes and the trim process on the final wafer patterns should be considered through the OPC development, it is necessary to moderate the interference between the OPC developments for the masks and to reduce the increase of required computational resources. The concept of the compact lithography model has been proposed, the results applied to random-logic designs have been shown, and effectiveness of the OPC flow has been discussed.

In this paper, we present some important improvements on our process window aware OPC (PWA-OPC). First, a CDbased process window checking is developed to find all pinching and bridging errors; Secondly, a rank ordering method is constructed to do process window correction; Finally, PWA-OPC can be applied to selected areas with different specifications for different feature types. In addition, the improved PWA-OPC recipe is constructed as sequence of independent modules, so it is easy for users to modify its algorithm and build original IPs.

We have developed a Character Projection (CP)-type, low-energy Electron-Beam Direct Writing (EBDW) system for a quick turnaround time and mask-less device fabrication of small production lots with a variety of designs. The exposure time has been decreasing because the irradiation time of electrons is being reduced by development of high-sensitivity resist and by decrease in the number of EB shots with the CP method, and the amplifiers of the deflectors have attained specifications required by EBIS. In order to further increase the throughput, overhead time, that is, the exposure waiting time, must be shortened. This paper describes our strategy for reducing the exposure waiting time. The reduction ratio of the exposure waiting time was about 60% and the throughput was increased about 20%.

A character projection (CP)-type, low energy, electron beam direct writing (EBDW) system, for quick-turn-around-time and mask-less device fabrications of small production lots featuring a variety of designs has been developed. This system, named the EBIS (Electron Beam Integrated System), can satisfy a set of requirements for EBDWs, including higher throughput and mask-less exposure. A standardized CP aperture method that enables reduction in the number of EB shots without frequent aperture making has been applied as a means for attaining effective CP and mask-less fabrication. This breakthrough was able to be realized only by using low energy EB with the advantage of the free proximity effect. To resolve critical low energy EB issues, a compact EB column, equipped with monolithic deflectors and lenses for restricting beam blur caused by Coulomb interaction, was developed and put to use. Sufficient resolution, corresponding to 100 nm L/S patterns, was attained by using a thin-layered resist process. As the mark detection method, voltage contrast imaging using a micro channel plate was used. This method made it possible to detect buried marks when using low energy EB. The authors are currently verifying the basic performance of this EBIS. This paper outlines and discusses geometrical details and performance data of this system.

In 1999, ADEOS-II is planned to launch. This satellite aims to observe the global changes of environment based on the carbon, water and energy cycle. For this purpose, ADEOS-II will carry several mission equipments. One of them is GLI (GLobal Imager). GLI is the imaging radiometer possible to observe various objects, for example, ocean color, sea surface temperature, vegetation index, cloud distribution, ice on the land and sea. To satisfy these abilities various methods will be applied to GLI. Collecting Optics consists of 2 off-axis parabolic mirrors to avoid the obstruction in the field of view. Interference filter are joined each other to set up many filter in the focal plane. Both faces of scan mirror will be used in terms of extending the integration time of detectors. In this report these methods and mission of GLI will be described.

New type of infrared instruments such as Tunable Etalon Remote Sounder for the Earth (TERSE) and High resolution Limb Infrared Absorption Spectrometer (HLAS) were proposed and studied for the future Japanese earth observation satellite program. This paper describes the results of feasibility study of TERSE and HLAS.

Computed radiography (CR) utilizing imaging plates (IPs), which consist of a photostimulable BaFX:Eu2+(X equals Cl,Br) phosphor, has found wide clinical use. In the present paper, a photostimulable SrFBr:Eu2+ (SFB) phosphor, as well as an IP employing this phosphor (SFB-IP), are experimentally prepared. A test apparatus for reading the SFB-IP is constructed, and the imaging characteristics are evaluated. The x ray imaging characteristics of the SFB-IP are different from those of the BFB-IP (the IP which consists of BaFBr:Eu2+). The difference is due to their x-ray energy absorption coefficients. Under the mammographic exposure conditions, the measurements of noise equivalent quanta as well as the visual evaluation of phantom images reveal that the SFB-IP and BFB-IP have the same quality level of imaging in spite of the PSL intensity of SFB being lower than that of BFB. However, for practical use, many problems are left on the SFB-IP and its reading apparatus.