Micro-interface formation control of electronic devises based on analysis of solid state bonding mechanism

在超高真空条件下观察了粘接行为，以了解基本的键合原理。Al、Au、Cu和Ni细线用作电路线，并且Au、Al、Cu和Ni箔用作电子焊盘。真空度为1 × 10 - <-8>4Pa。在键合之前，它们的表面通过Ar离子轰击进行清洁。俄歇分析发现，氩离子清洗前的表面有氧化膜，而氩离子清洗后氧化膜被去除。在Au-Au键合中，键合区域的形成是从接触区域的中心产生的，如Au-Ni键合和Au-Cu键合。然而，如果使用Al线，则首先键合外围区域，并且中心区域不容易键合。为了使这一现象更清楚，研究了粘合形成行为，并在键合后进行了俄歇分析。结果表明，即使在超高真空条件下，Ar离子清洗后几十分钟，Al表面也被氧吸附，形成了一层很薄的氧化膜，该氧化膜对附着力的形成有很大的影响。这是控制固态粘合过程的一个非常重要的知识。也就是说，在将Al线键合到焊盘的过程中，与焊盘接触的Al线的侧表面的折叠现象对于增加强键合面积是必要的。利用激光多普勒振动仪对键合工具的振动进行了测量，较好地控制了Al-Au、Al-Al、Al-Si键合界面的形成过程，获得了良好的界面形成条件。研究结果在Mate 2005国际学术研讨会上进行了报告，并形成了总结报告。

The adhesion behavior was observed under an ultra-high vacuum condition in order to comprehend the fundamental bonding principle. Al, Au, Cu and Ni fine wires were used as circuit wires and also Au, Al, Cu and Ni foils were used as a electronic pad. The vacuum degree was 1x10^<-8> Pa. Their surfaces were made clean by Ar ion bomberdment before bonding. It was found that the surfaces before Ar ion cleaing has an oxide film but the oide film is removed by Ar ion cleaning based on Auger analysis. In Au-Au bonding, the bonded area formation is produced from center of contacted area as like as Au-Ni and Au-Cu bonding. However, if Al wire is used, the periphery area was firstly bonded and the center area is not easily bonded. In order to make this phenominon to be clear, the adhesion formation behavior was investigated and Auger analysis was carried out after bonding. As a result, it was suggested that the surface of Al was attacted by oxygen and a very thin layer oxide film was formed several ten miniutes after Ar ion cleaning even under the ultra-high vacuum condition and the film had a large influence on the adhesion formation. This is an very important knowledge to control the solid state adhesion process. That is, the folding phenomenon of side surface of Al wire contacted to the pad is necessary for increasing the strong bonded area during the the bonding of Al wire to the pad. Taking this idea into consideration, the interface formation process of Al-Au ar Al-Al, Al-Si bondings was controlled well and also the good formation condition was obtained by measuring the vabration of the bonding tool using leaser Dopplar vibriometer. The results were reported in Symposium of Mate2005 and the final report was made.