Submicron Contact Hole Electromigration Failure Study

The reliabilities of semiconductor are important topics for industry, and electromigration (EM) failure is the most important and persistent challenge among them. In recent years, some 5 inch and 6 inch manufactories closed.But the requirement of submicro product is still growth. And the spiking issue of aluminium contact is the major factor of submicro contact EM failure. So studying the process effects on aluminium contact spikeing problems will help to better understand EM phenomena and provide solutions for industry. Also, it is beneficial to the technical advancement of semiconductor industry in China.The deeply study is carried out on the EM test sturcture and condition on both package level and wafer level. The substrate leakage test structure and condition for contact spiking issue is proposed in wafer acceptable test(WAT). It is helpful to improve the efficiency to detect contact spiking issue and reduce the reliability test cycle.This dissertation systematically studied the fabrication process effects on contact spiking issue in submicron aluminium connects. For the fact that physical parameters determined by manufacturing processes, the dissertation then discussed the characters of submicro aluminium interconnect technology and concluded that improtant processes including contact dry etch, glue layer pre clean, interface and material properties-dominate the contact spiking issue of submicron aluminium interconnects. The substrate leakage test structure of contact spiking issue was implemented in submicro process, and was proved by experimental results. The experimental results show strong correlation between contact yield loss and TiN film. For the interface effects, the study focused on the Ti and N element proportion in TiN film. Finally, the TiN film by new process condition solved the contact spiking issue.