C. Fisher and the approximation solution of Le Claire, thermal diffusivity of copper in Ta and TaN layer was calculated. The diffusion coefficient of Cu in Ta is one order larger than that in TaN (T=630oC).

• 利用Fisher扩散原理和Le Claire简化公式，计算并比较了Cu在TaN和Ta中的晶界扩散系数，前者比后者小一个数量级（T=630oC）。