MULTIPHOTON MICROMETER-SCALE PHOTOETCHING IN SILICATE-BASED GLASSES

Silicate-based glasses containing approximately 10% by weight boron or more have been observed to exhibit selective etching in hydrofluoric acid solution after direct exposure to intense visible laser light at 532 nm; The observation of a ring-shaped etch pattern in samples expos ed to solid Gaussian beams suggests that selective etching is related to a charge-diffusion process rather than to local light-induced defec t generation. The technique has so far resulted in the maskless produc tion of micrometer-scale features with submicrometer depths.