Microstructure evolution in damascene interconnects

We have developed a 3-dimensional computer simulation tool to study the characteristics of microstructure evolution in damascene interconnects. This tool is based on the Monte Carlo method, and the characteristics of the microstructure evolution have a significant impact on the interconnect reliability. Our simulation results show that it may not be possible to obtain a bamboo microstructure that minimizes electromigration failure in a damascene trench structure if its aspect ratio is much higher than unity. We also find that the bamboo microstructure can be obtained when the seed texture is random.