Unique Features of Laser Ablation

Abstract

ABSTRACTThe advantage and disadvantage of laser ablation as a thin Film deposition technique are discussed on the basis of my own experiences. High instantaneous growth rate is useful to produce amorphous films, and reactive deposition can be achieved by gases introduced in the deposition chamber. Combining these two features, hydrogenated amorphous silicon films were produced. Laser ablation is characterized by the presence of energetic neutrals and ions in beams, which helped to deposit diamond-like carbon films. Also selective-area deposition is made possible by placing a mask between the target and substrate. In pulsed laser ablation the mask must be placed close to the substrate to avoid the spreading of deposits. The thickness profilr can bc controlled by residual gas pressure, and using this technique microlenses were fabricated, in addition to ridge-type optical waveguides. The particle problem which plagues laser ablation is more serious for targets with low fractional ionic character. The usefulness of a molten target as the means to eliminate particles was confirmed for aluminum.