HIGH-DENSITY MASTERING USING ELECTRON-BEAM

A mastering system for the next-generation digital versatile disk (DVD ) is required to have a higher resolution compared with the convention al mastering systems. We have developed an electron beam mastering mac hine which features a thermal field emitter and a vacuum sealed air sp indle motor. Beam displacement caused by magnetic fluctuation with spi ndle rotation was about 60 nm(p-p) in both the radial and tangential d irections. Considering the servo gain of a read-out system, it has lit tle influence on the read-out signal in terms of tracking errors and j itters. The disk performance was evaluated by recording either the 8/1 6 modulation signal or a groove on the disk. The electron beam recordi ng showed better jitter values from the disk playback than those from a laser beam recorder The deviation of track pitch was 44 nm(p-p). We also confirmed the high density recording with a capacity reaching 30 GB.