Effect of silicon nitride deposition parameters on TDDB performance of SiN<inf>x</inf>-MIM capacitors

Abstract

Silicon nitride (SiN x ) is commonly used as the dielectric or insulator material for metal-insulator-metal (MIM) capacitors. The deposition of SiN x can be performed using plasma-enhanced chemical vapor deposition (PECVD) method with different deposition parameters by changing individually the SiH 4 flow rates, NH 3 flow rates, RF power, substrate temperature, etc. Time-dependent dielectric breakdown (TDDB) is the most important reliability test item to check the intrinsic performance of the MIM capacitor dielectrics. In this study, the effect of several SiN x deposition parameters on the dielectric TDDB performance of SiN x MIM capacitors has been studied: silane (SiH 4 ) gas flow rate, RF power and ammonia (NH 3 ) gas flow rate. The constant voltage TDDB lifetime performances for different conditions were compared and discussed for MIM capacitor optimization and the mechanism behind the effect was discussed.