ATOMIC-FORCE MICROSCOPY OF LASER-INDUCED SUBMICROMETER PERIODIC STRUCTURES ON IMPLANTED FUSED-SILICA AND SILICON

The ultrathin layers with depth from 30 to 60 nm and optical absorptio n coefficient up to 10(5) cm(-1) were created on the fused silica and crystalline silicon surfaces by Fe and Sb ions bombardment respectivel y. Nanometer-scale alpha-Fe particles formed into glass surface layer by high dose Fe+ bombardment were responsible for optical absorption i n the Fe+ implanted fused silica. The increase in the optical. absorpt ion of Si after Sb+ implantation are due to transformation of the sili con surface layer from the crystalline to the amorphous state. These l ayers were found to be easily evaporated by pulsed beam of UV and visi ble lasers due to their high light absorption. Such materials may be p romising in manufacturing the video disk master. The sub-micrometer di ffraction gratings were produced using holographic method in order to estimate the possible resolution of these media for optical data stora ge. it was found with Atomic Force Microscope (AFM) that microtopograp hy of laser-induced diffraction gratings is determined by the size of optical absorption centers. After treatment with higher laser power de nsity the half-micrometer bi-directional diffraction gratings on impla nted silicon were observed by AFM. The origin of these gratings was ex plained in terms of the laser-induced surface electromagnetic waves.