Laser writing of submicrometre lines on copper island films

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