High-density groove mastering using an electron beam recorder and plasma etching process

An electron beam recorder (EBR) has been confirmed to have high-resolution performance and we think it is a promising recorder to produce a master stamper for the next-generation high-density optical disks. Because the high-density groove recording disk requires a narrower track pitch, the improvement of the recording resolution of the mastering recorder is necessary. However, owing to electron scattering, fabricating a groove structure was difficult even when we use a finely controlled conventional EB mastering process. A plasma etching process is an expected process as one of the solutions. Consequently, we adopted the plasma etching process for high-density groove disk mastering. A data bit length of 112 nm/bit was successfully recorded on the groove disk at a wavelength of 405 nm and an objective lens of 0.85 numerical aperture.