Breakdown voltage and TDDB performance improvement by optimizing the PECVD dielectric film characteristics in MIM capacitors

Abstract

The dielectric breakdown voltage (BV) and time dependent dielectric breakdown (TDDB) are the most important concerns for device reliability. In this study, the silicon nitride (SiNx) used as metal-insulator-metal (MIM) capacitor dielectric was successfully prepared by a dual-frequency plasma enhanced chemical vapor deposition (PECVD) method. Fourier transform infrared (FTIR) absorption spectra and electrical characterization results suggest that the SiNx film possesses higher dielectric breakdown voltage performance by decreasing SiH4/NH3 gas flow ratio or optimizing the interface layer among multiple layers. Similarly, the TDDB reliability test based on Weibull distribution indicates an increase in failure lifetime of the MIM capacitors by adjusting RF power and NH3 gas flow.