A particle filtering method for pulsed laser deposition

Abstract

This paper describes both the velocity distribution of laser-ablated tantalum atoms in a plume and the plume temperature in order to discuss the behavior of particles inpulsed laser deposition (PLD). Optical time-of-flight (TOF) was used for the analysis. The velocity distributions of tantalum atoms ablated at the laser fluence in a range of 4-20J/cm2 agreed well with the Maxwell-Boltzmann distribution with center-of-mass velocity. This agreement enabled us to estimate the atom density distribution in the plume.Based on the analysis of atom density distribution in the plume, a simple particle filter for PLD using a pair of thin plates with parallel slits was designed to reduce the number of large particles, such as splashed liquid, which often deposit on the film surface causing to deterioration in film properties; i.e., in transparency, uniformity and corrosion resistance.With the particle filter, tantalum films with a smooth and particle-free surface were obtained in a vacuum over a range of 10−3-10Pa.This paper describes both the velocity distribution of laser-ablated tantalum atoms in a plume and the plume temperature in order to discuss the behavior of particles inpulsed laser deposition (PLD). Optical time-of-flight (TOF) was used for the analysis. The velocity distributions of tantalum atoms ablated at the laser fluence in a range of 4-20J/cm2 agreed well with the Maxwell-Boltzmann distribution with center-of-mass velocity. This agreement enabled us to estimate the atom density distribution in the plume.Based on the analysis of atom density distribution in the plume, a simple particle filter for PLD using a pair of thin plates with parallel slits was designed to reduce the number of large particles, such as splashed liquid, which often deposit on the film surface causing to deterioration in film properties; i.e., in transparency, uniformity and corrosion resistance.With the particle filter, tantalum films with a smooth and particle-free surface were obtained in a vacuum over a range of 10−3-10Pa.