Nouveaux développements et applications en microfabrication laser.

Laser microprocessing has conquered many applications ranging from microelectronics to biomedical technologies.Typical applications are via drilling of PCB-layers or cutting of medical stents. Most processes are based on the precise ablation of material using laser pulses in the nanosecond time regime. Nanosecond laser pulses which are generated by q-switching provide power levels of several hundred watts resulting in sufficient throughput for these systems. The trend towards further miniaturization requires new principles of further avoiding any melting of material. Modelocked picosecond and femtosecond laser pulses have demonstrated the potential to overcome existing barriers.

The presentation gives an overview about the principles of interaction between an ultrashort laser pulses and different kind of materials. The basic equations result in a two-temperature model describing the temperatures for the electrons and lattice without achieving a equilibrium during the course of the pulse. It has been shown that ultrashort pulsed laser processing can provide a powerful tool for micromachining nearly any kind of material and geometry (bulk and thin-film). Pulse energy and pulse repetition rate are important parameters which determine the precision, process efficiency, and throughput. It is shown, that by adapting the parameters holes with almost geometrical quality and aspect rations larger than 10 can be drilled in metals with superior reproducibility. For expanding the precision to nanostructuring, nonlinear interactions have to be taken into account to overcome the diffraction limit of conventional optics. Multiphoton processing, however, becomes gradually material dependent in the nanometer range. Therefore, material and laser beam have to be adjusted to each other. By using an ultrafast laser at a wavelength of 800 nm it is possible to generate structures below 100 nm. Potential applications in the photonics and nanoelectronics area will be discussed. It will also be shown how lasers can be used to generate nanoparticles and nanocomposites materials which are useful materials in many kinds of active MEMS devices.

Prof. Dr. Andreas Ostendorf

Ruhr-University Bochum, Germany

Email: Andreas.Ostendorf@ruhr-uni-bochum.de

Note : la présentation a été faite par E. Mottay / AMPLITUDE SYSTEMES, remplaçant en dernière minute A. Ostendorf.