Rutherford Backscattering Spectrometry Studies on Copper and Chromium Diffusion in Polyimide

Abstract

AbstractDiffusion of Cu in polyimide(PI) film was observed after Cu evaporation on PI at room temperature. Annealing treatment significantly enhanced the diffusion of Cu. The diffusion coefficient measured at 200 and 400 C using the Fickian erfc solution are 3 × 10−14 and 1 × 10−13 cm2/sec, respectively. Cu shows the Fickian diffusion behavior. In contrast to Cu, no clearly measurable diffusion had occurred for an as-deposited Cr specimen and a specimen annealed at 400 C for 1 hour. However, for longer annealing times a slight amount of Cr diffused into PI because of the growth of the intermixed region. The diffusion coefficients of Cr at 200 and 400 C for less than 20 hours are 2 × 10−15 and 7 × 10−15 cm2/sec, respectively. The diffusion of Cr in PI shows non-Fickian behavior.