W. Y. Cheng, Taiwan Semiconductor Manufacturing Company, Hsin-Chu, Taiwan

Summary: Several methods and tools have been used for FA defect isolation; emission microscopy (EMMI) is the most popular tool among these techniques. But for advanced products, the working voltage is getting more and more small, thus many emission spots from normal transistors will be observed, which indeed impacts the judgment on the emission spots from real defects and increases the FA difficulty. Laser scanning microscopy has been a common technique for failure site isolation for these years, which can detect some defects that is not easy to catch by EMMI such as higher resistance, short and S/D contact open. Furthermore, the defects are at the same locations of spots that reduce much time for layout tracing before PFA.