Effect of hydrogen remote plasma annealing on the characteristics of copper film

Abstract

The effect of hydrogen remote plasma annealing on the characteristics of copper film such as resistivity, chemical composition and morphology was investigated. The hydrogen remote plasma enhanced the reflow of Cu and the preferential growth of Cu (111). With the increase of H-2 gas flow rate ratio {[H-2]/([H-2] + [N-2])}, plasma treatment time, and RF power, the resistivity of Cu film decreased due to the removal of impurity inside the film. The surface roughness decreased due to the smoothing of the surface, as the annealing time was increased up to 5 min but above that, the surface roughness increased because of agglomeration. The profile of Cu film in the trench opening became more conformal due to the enhanced reflow. (C) 2003 Elsevier Science B.V. All rights reserved.