Effect of silicon nitride deposition parameters on TDDB performance of SiNx-MIM capacitors

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.