Study of optimization guidelines on nitrogen concentration in nitrided oxide for logic and dynamic random access memory application

In this paper, we report on the issues and optimization guidelines for nitr ided oxide (NO) gates for logic and dynamic random access memory (DRAM) dev ices. We intensively studied the dependence of device characteristics on th e nitrogen concentration in NO gates. In the case of logic devices, degrada tion of short channel characteristics in n-channel metal oxide semiconducto r field effect transistors (NMOSFETs) and degradation of drive current in p -channel MOSFETs (PMOSFETs) limits the maximum nitrogen concentration. In D RAMs, an additional V-T dose to compensate for the decrease of V-T in NO ga tes causes a degradation in the refresh time pel performance due to the inc rease of the electric field in the space-charge region. This reveals that, for NO-gate DRAM, the nitrogen concentration should be minimized to prevent the degradation of refresh characteristics.