Micromachining of FM/M/FM films using an active Q-switched Nd:YAG laser

We have optimized the operation conditions of the laser for the patterning in the FM/M/FM multi-layer, which can be readily used for the fabrication of the micro thin-film inductor. A diode-pumped Nd:YAG laser was actively Q-switched in order to obtain a high power short pulse laser beam whose spatial mode was TEMinfinity mode. The measured pulse width was about 200 ns, its peak power was 25 kW, and the used pulse repetition rate was set to be 5 kHz. The optimal energy of a laser pulse was found to be 5 mJ and the focused beam with diameter of 5-10 mum was launched to the FM/M/FM multi-layer. Due to the high intensity of the laser beam, the major interaction between laser beam and the material is vaporization rather than melting. The pattern formed by this vaporization process was very clear and had a line width as narrow as 20 mum. (C) 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.