SUPPRESSION OF THERMOCAPILLARY WAVES IN LASER MELTING OF METALS AND SEMICONDUCTORS

A theoretical study of surface relief stability in the laser melting o f materials with relatively high thermal diffusivity and/or relatively high absorption coefficient (mainly metals and semiconductors) is giv en. Irradiation regimes are found where it is possible to avoid the de velopment of surface wavy relief of the nonresonant type (with periodi cities much greater then the radiation wavelength) both for cw and pul sed 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.