Münster 1999 – scientific programme

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DS: Dünne Schichten

DS 16: Charakterisierung mittels SXM-Techniken I

DS 16.2: Invited Talk

Tuesday, March 23, 1999, 10:15–11:00, PC 7

Thermal nano-phase change of an Antimony thin film and the application for optical near-field data storage — •J. Tominaga and T Fukaya — National Institute of Advanced Interdisciplinary Research (NAIR)// Ministry of International Trade and Industry (MITI)

Thermal nano-phase change of an Antimony (Sb) thin film sandwiched by dielectric layers were investigated, and the application for super-density optical data storage by optical near-field was described. An Sb thin film with a thickness of 15 nm showed a switching property of an optically reversible nanometer-window with a huge refractive index change in less than 100 nm diameter. We have applied this reversible nano-phase change property to optical data storage as a recording and readout aperture to produce optical near-field. An optical disk was fabricated with a structure of SiN(170 nm)/Sb(15 nm)/SiN(20 nm)/GeSbTe(15 nm)/SiN(20 nm) on a polycarbonate substrate in this order by sputtering technique. A thin film of GeSbTe was used as a recording layer. By adjusting the film thickness of the SiN between the Sb and the GeSbTe layers to about 20 nm, it becomes possible to produce a near-field coupling between the Sb nano-aperture and recorded marks in the GeSbTe film. When a wavelength of 635 nm and an optical pickup used in a current DVD with a NA of 0.6 were applied for recording and readout of tiny marks beyond the diffraction limit ( 200 nm) of the system, small marks with a size of less than 100 nm were recorded and retrieved by optical near-field coupling at the same disk rotation speed as that of DVD.