The SAS Implant Integration Optimization in the Cell Scaling of 4Xnm ETOX NOR Flash

The Vertical direction polysilicon height down plays an important role in the cell size shrink of ETOX NOR flash, and the Self-aligned source (SAS) implant process is one of the restrict factor of polysilicon height. In this paper, we optimize the SAS loop implant process energy and dosage to achieve an ingenious balance between source side implant ion and the punch through of tunneling oxide. Finally, the performance of optimized of SAS loop process are investigated by the wafer accept test (WAT), chip probe (CP) and TCAD simulation.