Reduction of Droplet Formation by Reducing Target Etching Rate in Pulsed Laser Ablation

Droplet formation in the film and maximum etching depth of the target in the process of pulsed-laser-ablation (PLA) deposition were investigated by scanning tunneling microscopy and stylus profilometry, respectively. The ratio of the droplet volume to the film volume (V d/V f) was found to be proportional to d 3 e (d e being the maximum etching depth of the target) for a variety of ablated materials and wavelengths of the laser. This fact suggests that a laser with a low fluence, a short wavelength and a short pulse width, and a high-density target are preferred for the preparation of film with fewer droplets.