Structural changes in Se-Te bilayers by laser writing

Transmission electron microscopy is used to characterize the hole-formation process due to laser writing in evaporated and sputtered Te thin films and in a Se-Te bilayer. Bilayers, with Se as the top layer, combine the effect of an antireflective coating with protection against oxidation and provide the advantage of alloy formation during spot writing. Solidification of the melt in the Se-Te spot takes place as an amorphous alloy resulting in smooth-rimmed, clean holes. In contrast, Te crystallizes from the melt, giving rise to uneven rims and debris inside the spot.