SUPPRESSION OF THERMOCAPILLARY WAVES IN LASER MELTING OF METALS AND SEMICONDUCTORS

A theoretical study of surface relief stability in the laser melting of materials with relatively high thermal diffusivity and/or relatively high absorption coefficient (mainly metals and semiconductors) is given. Irradiation regimes are found where it is possible to avoid the development of surface wavy relief of the nonresonant type (with periodicities much greater then the radiation wavelength) both for cw and pulsed irradiation. The results obtained can have important consequences for the improvement of the quality of laser materials processing, e.g., in laser applications for microelectronics, or in laser modification of a surface.