Development of an Apparatus for Measuring Submicroscopic Current Distribution and Evaluation of Interface Delamination and Atom Migration irr Electronic Devices

1.用直流电位法预测多裂纹的电场分布提出了一种分析多裂纹周围电场的裂纹电流修正法。对三维导体中随机分布的圆盘状裂纹和二维导体中分布的贯通裂纹进行了电场分析。在分析结果的基础上，提出了用直流电位法预测多裂纹分布的方法。存在于导电材料表面正下方的小缺陷的评估利用带有电流测量系统的扫描探头微锥来评估存在于导电材料表面正下方的小缺陷，该系统通过悬臂将电流提供给导体，并通过电流的变化来评估缺陷。采用裂纹-电流改进法对多个裂纹周围的电场进行了分析，讨论了该装置的基础。实际电流测量表明，悬臂梁与试件之间的接触条件或接触电阻对电流大小有很大影响。为了找到最佳的测量条件，模拟接触面积有意波动的装置进行了电学分析。得到了以下结果。有必要对悬臂尖端的形状进行修改。悬臂梁的伺服机构有待进一步研究。

1. Electric field analysis for predicting the distribution of multiple cracks by means of direct current electrical potential methodCrack-current modification method was proposed for analyzing the electric field around multiple cracks. Electric field analysis was carried out for randomly distributed disk-shaped cracks in a three-dimensional conductor and for distributed through-cracks in a two-dimensional one. Based on the results of the analysis, a procedure was proposed for predicting the distribution of multiple cracks by direct current electrical potential method.2. Evaluation of a small defect existing right under the surface of conductive materialsA small defect existing right under the surface of the conductive material was evaluated by means of a scanning probe microscone with current measuring system where electric current was supplied through a cantilever to the conductor and the defect was evaluated by the change in the current. Electric analysis was carried out for discussing the basis of this apparatus by the crack-current modification method which was used for the electric field analysis around multiple cracks. It was clarified by actual current measurement that contact condition or contact electric resistance between the cantilever and the specimen has a great influence on the amount of current. In order to find the best measuring condition, electric analysis was carried out simulating the apparatus in which the contact area was fluctuated intentionally. The following results were obtained. Modification of the shape of a cantilever tip is necessary. Further development is needed on the servomechanism of cantilever.