Abstract：
Indium (In) and other low melting point metals are used as interconnects in a variety of hybridized circuits and a full understanding of the metallurgy of these interconnects is important to the reliability and performance of the devices. This paper shows that room temperature focused ion beam (FIB) preparation of cross-sections, using Ga+ or Xe+ can result in artifacts that obscure the true In microbump structure. The use of modified milling strategies to minimize the increased local sample temperature are shown to produce cross-sections that are representative of the In bump microstructure in some sample configurations. Furthermore, cooling of the sample to cryogenic temperatures is shown to reliably eliminate artifacts in FIB prepared cross-sections of In bumps allowing the true bump microstructure to be observed.
摘要：
铟（In）和其他低熔点金属被用作各种混合电路中的互连，并且对这些互连的冶金的充分理解对于器件的可靠性和性能很重要。本文研究了室温聚焦离子束(FIB)制备的横截面,使用Ga+或Xe+可导致模糊真实In微凸块结构的伪影。使用改进的铣削策略来最小化增加的局部样品温度显示出在某些样品配置中代表凸点微观结构的横截面。此外，将样品冷却至低温，可以可靠地消除In凸块的FIB制备的横截面中的伪影，从而可以观察到真实的凸块微观结构。
