The development of dual gate poly scheme with plasma nitrided gate oxide for mobile high performance DRAMs: plasma process monitoring and the correlation with electrical results

The in-line plasma process monitoring was successfully performed with non-contact direct measurement (NCDM) tool and its results were well matched with those from devices. Using this monitoring method, we developed a plasma nitrided gate oxide process for mobile DRAMs with low operating voltage. We confirm that plasma nitrided gate oxide can block the boron penetration in DRAMs, which has higher thermal budget than other devices, and that the NCDM tool can be used for checking the degree of plasma nitridation. We assure that the NCDM tool is a time-effective tool for plasma nitridation process development.