The Impact Of The Manufacturing Process Of Ultra-deep Sub-micron Aluminum Interconnects Through-hole Stress Migration Reliability

The reliability of integrated circuits is an important subject for industry and academy, and stress migration (SM) failure is the most important and persistent challenge among them.Although the leading edge of semiconductor technology has been developed to the field of nano-CMOS, copper interconnects in high-performance devices have been widely used, but the aluminum interconnect technology is still used in the current mass production of ultra-deep submicron (0.15-0.18 micron) integrated circuit. But the traditional Al interconnect technology is still encounter a variety of stress migration problems, so the research of manufacturing process parameters and steps related Al interconnect stress migration is conducive to understanding the phenomenon of stress migration, and has practical value for industrial applications.This thesis first analyzes the reasons for stress migration reliability failure, according to the stress migration lifetime relationships with a variety of physical parameters measure the lifetime of SM on the 0.15-micron chip, analyzes resistance distribution model of via, and find the interface contact resistance the bottom of via can significantly affect the via resistance.Define the location of stress migration failure in the failure chip by transmission electron microscopy to, and find the fluorine and carbon between TiN on the Al and Ti as barrier layer by Auger spectroscopy depth component analysis, which leads to a sharp increase in via resistance and stress migration reliability failure.The experimental part of this thesis discuss the RIE and ICP process optimizing the via etching process by reducing the concentration of 02 and increasing the concentration of Ar; process in oxygen plasma to remove polymer by adding H2+N2 gas, enhancing the ability to remove the polymer. improved stress migration reliability.