Development of Prediction Method for Metal Line Failure Induced by High Current Density

1.为了模拟多晶线的失效过程，在网格剖分过程中引入了狭缝单元。根据电迁移损伤控制参数的计算值，只减小了狭缝单元的厚度。因此，建立了多晶线失效过程的数值模拟方法，可用于多晶线寿命和失效位置的预测.预测了斜多晶线的寿命和失效位置。处理的线条在膜特性和线条形状上是不同的。另一方面，在与预测相同的线形状、膜特性和操作条件下进行了实验。对寿命和失效位置的预测与实验结果吻合较好。实验验证了多晶线失效预测方法的有效性.通过原子力显微镜观察竹线条的破坏过程，发现竹线条中的空洞以浅凹的形式出现，而不是狭缝的形式出现，空洞随着空洞表面的刮削而增长.提出了一种竹线条破坏过程的数值模拟方法。在模拟中，金属线被划分为单元，而不引入狭缝状单元。通过改变单元的厚度，利用电迁移损伤的控制参数对竹纤维的破坏过程进行了数值模拟.预测了斜竹线条的寿命和失效部位。另一方面，在与预测中的那些相同的线形状和相同的操作条件下进行实验。对寿命和失效位置的预测与实验结果吻合较好。实验验证了该方法对竹线失效预测的有效性。

1. In order to simulate the failure process in polycrystalline line, slit-like elements were allocated in the mesh generation. The thickness of only the slit-like element was decreased based on the calculated value of the governing parameter for electromigration damage. Thus, a method of numerical simulation of the failure process was developed for the prediction of lifetime and failure site in polycrystalline lines.2. The lifetime and failure location of angled polycrystalline lines were predicted. The lines treated were different in film characteristics and line shape. On the other hand, experiment was performed with the same line shape, film characteristics and operating condition as those in the prediction. Good agreement between the predictions and the experimental results was obtained for the lifetime and the failure location. The usefulness of the prediction method for polycrystalline line failure was verified experimentally.3. By atomic force microscopic observation of failure process in bamboo lines, it was found that voids in bamboo lines appeared in the form like a shallow depression, not like a slit, and that the voids grew with shaving the surface of the void.4. A method of numerical simulation of the failure process in bamboo lines was developed. In the simulation, the metal line was divided into elements without introducing slit-like elements. By changing the thickness of each element, the failure process was simulated numerically using the governing parameter for electromigration damage in bamboo lines.5. Lifetime and failure site of angled bamboo lines were predicted. On the other hand, experiment was performed with the same line shape and under the same operating condition as those in the prediction. Good agreement between the predictions and the experimental results was obtained for the lifetime and the failure location. The usefulness of the prediction method for bamboo line failure was verified experimentally.