NANOSCALE MODIFICATION OF PHASE-CHANGE MATERIALS WITH NEAR-FIELD LIGHT

Scanning near-field optical microscope (SNOM) was applied to the forma tion of ultrasmall phase change domains to investigate the feasibility of ultrahigh density data storage. Phase change domains ranging 60 - 100 nm in diameter, which is far beyond the diffraction limit, could b e successfully written in amorphous GeSbTe recording film by point hea ting with pulsed laser light (lambda = 785 nm, 7 mW. 0.5 ms) through t he optical fiber probe whose aperture size was nearly 50 - 100 nm. The detected power in observation of these recorded domains is 10(2) - 10 (3) times as high as that in magneto-optical observation. It indicates that phase change recording with SNOM has a potential to achieve ultr ahigh density data storage (more than 100 Gb/m(2)) with high signal de tection efficiency.