Vacuum deposition of thin films with a pulsed laser

Abstract

Pulsed laser ablation is used to produce thin films in a ultra-high vacuum system. This vaporization technique produces beams of particles the characteristics of which are different from those obtained by classical thermal evaporation processes. The authors describe an evaporation system using a pulsed Nd-YAG laser which gives a power density larger than 10+8 W/cm2 on the target. The beam is moved in one direction and the target holder is translated in the orthogonal direction, leading to a continuous scanning of the target surface. The thickness of the layers is monitored by a quartz micro-balance. The whole system is controlled by a computer enabling automated deposition of multilayers. Thin films of W, Ni, Rh, C, and Si were made with this evaporation system. The characterization of these films by grazing angle X-ray reflectometry indicates that their density is nearly equal to the bulk value.