Investigation of metal-organic chemical vapor deposited copper diffusion in tantalum after annealing

Abstract

We have carried out direct diffusion measurements of metal organic chemical vapor deposition (MOCVD) Cu into Ta and Ta into cvd Cu. Copper films deposited by MOCVD technique of 500nm thickness were grown onto a thick Ta layer of 1μm deposited by Ionized Metal Plasma (IMP). Samples were annealed in a furnace system from temperatures ranging from 300°C to 550°C for periods of 1/2 an hour. The electrical and mechanical properties of the structures were examined by experiments such as sheet resistance, atomic force microscopy (AFM), scanning electron microscopy (SEM), and x-ray diffraction (XRD). The diffusion profile was performed using Secondary ion mass spectroscopy (SIMS). The Cu diffusion coefficient in Ta can be described by 2.845 × 10-14 exp (-0.1452eV/kT) cm2/s while the Ta diffusion coefficient in Cu can be described by 1.3417 × 10-13 exp (-0.267eV/kT) cm 2/s. © 2002 IEEE.