An application of cathodoluminescence to optimize the shallow trench isolation process

Cathodoluminescence (CL) spectroscopy was applied to optimize the shallow trench isolation (STI) process. The analysis of dislocations with CL spectroscopy could be performed during STI process steps. Then, the result of CL analysis was associated with the failure of a junction leakage current. Moreover, the analysis contributed to identifying the failure, including the root cause. As the result of CL analysis, nitride film thickness used as a mask layer of patterning was controlled at 190 nm or less. The dislocation analysis with CL spectroscopy can reduce the cycle time from 50 to 5 days.