Laser writing of submicrometre lines on copper island films

Abstract

Laser writing on copper island films is demonstrated for the first time. Very fine lines with widths of less than 1μm have been written using a commercially available 0.82 μm 20 mW laser diode. The reflectance of the 8nm-thick copper island film is 49% at a wavelength of 0.82μm and it has been reduced to 15% by the irradiation of the focused laser beam due to the oxidisation of copper islands. The Cu island film is considered as a new medium for an efficient heat-mode write-once memory.