Effect of defectivity reduction in Spacer and Junction modules on RMG defectivity

摘要

Defect elimination from the Spacers and Junctions modules has been shown to increase yield in 20 nm HVM (high volume manufacturing). However, other defects such as surface particles and lifted pattern were also found in these modules. These defects formed voids downstream and later were filled with metals in the RMG (replacement metal gate) process. Therefore, these defects also need to be eliminated in order to meet entitlement yield. These defects were traced through the line from their origination in the Spacer and Junction modules into RMG and MOL (middle of line) modules. Surface particles and lifted pattern were eliminated by developing a new photoresist stripping (PRS) process. The effectiveness of the new PRS process was verified by defect elimination in the Spacer and Junctions and in the downstream RMG module. Defectivity reduction and electrical data will be presented to show the effectiveness of this new PRS process.