Impact of pattern density on plasma damage of CMOS LSIs

This paper proposes a new plasma damage model that can explain and estimate the plasma damage in a CMOS LSI by taking into account the additional factor of pattern density. Reliability data presented in this paper shows that plasma damage to MOSFET gate oxide in a CMOS LSI cannot be fully explained by considering only antenna and aspect ratio theory. To verify the model on a CMOS LSI, a test pattern was designed with three parameters; antenna ratio, aspect ratio and pattern density. It is concluded that CMOS LSI reliability results were explained by this new model. This model should be taken into account when designing CMOS LSI circuits to avoid damage by plasma processes.