A two-dimensional recording method that achieves double recording density by reducing the track pitch is described. This method uses a flat disk and the data are recorded with circular marks on lattice points. Two-dimensional interference consisting of crosstalk and inter-symbol interference is reduced by two-dimensional equalization. To minimize the two-dimensional interference, the optimum equalization coefficients are calculated dynamically with the reproduced signal of the training marks. Reproduction was simulated and this showed that the signal-to-noise ratio of the processed signal was 24.3 dB under ideal conditions and 19.8 dB under worst-case conditions with the usual magneto-optical media using double recording density. These simulation results were checked by a recording/reproduction experiment. The experimental result for the signal-to-noise ratio of the processed signal was 23.6 dB with an areal density of 2.3 Gbit/in2.

We propose new test device structures, Gate-Last-formed structures, which are suitable for fundamental study of high-k gate insulator or metal gate electrode MISFETs. The gate insulator and electrode stack is formed after local interconnect pads connected with source and drain. The gate stack is build in trench formed by dry and wet etching and is non-self-aligned to the source and drain. The wet etching restricts damage formation on the exposed Si surface underneath the trench. Electrical characteristics are measurable just after exposure of surface of the local interconnect pads without conventional Al wiring. This structure can provide methods both for fundamental evaluation and for material selection of new gate stack materials by investigation of MISFET characteristics. This is achieved with short TAT and avoiding contamination penalty to a fab.

A high speed, large capacity optical disk for commercial applications is developed. This disk system adopts both the pit-edge recording method and the MCAV method. New techniques, which can use these methods together and are suitable for interchangeability, are developed: Independent detection of leading/trailing edge and data composition. Consequently, the most reliable file system to date has been achieved.

Computer circumstance have changed drastically, and larger capacity removable media is indispensable. Magneto-optical disk is promising candidate to satisfy computer user's needs. In this report, future perspective of high density magneto-optical recording technology is investigated.