Laser Cleaning of Particles from Silicon Wafers: Capabilities and Mechanisms

Laser cleaning of particles from silicon wafers: capabilities and mechanisms

Introduction The preparation of surfaces free of particle contamination is one of the crucial prerequisites for a further increase in the integration density of ICs and for the progress in nanotechnology. Therefore the removal of sub-micron sized particles from silicon wafers is of great interest. For this purpose a variety of cleaning methods is currently under investigation. In semiconductor ...

Laser Cleaning of Silicon Wafers: Mechanisms and Efficiencies

We report on experiments on the underlying physical mechanisms in the Dry(DLC) and Steam Laser Cleaning (SLC) process. Using a frequency doubled, Q-switched Nd:YAG laser (FWHM=8 ns) we removed polystyrene (PS) particles with diameters from 110-2000 nm from industrial silicon wafers by the DLC process. The experiments have been carried out both in ambient conditions as well as in high vacuum (10...

Ultraviolet laser removal of small metallic particles from silicon wafers

Laser removal of small 1mm sized copper, gold and tungsten particles from silicon wafer surfaces was carried out using ultraviolet radiation at 266 nm generated by Nd:YAG harmonic generation. Successful removal of both copper and gold particles from the surface was achieved whereas tungsten particles proved to be difficult to remove. The cleaning efficiency was increased with an increase of las...

Laser assisted particle removal from Silicon wafers

We have studied the removal of submicrometer particles from silicon wafers by the steam laser cleaning (SLC) and dry laser cleaning (DLC) processes. These processes are currently being investigated as new promising cleaning technologies for complementing traditional methods in industrial applications. For SLC a thin liquid layer (e.g. a water-alcohol mixture) is condensed onto the substrate, an...

Removal Versus Ablation in KrF Dry Laser Cleaning of Polystyrene Particles from Silicon