Impact of Gate Metal Work Function on 1/f Noise in RMG MOSFETs

Abstract

This study explores how gate metal work function affects 1/f noise in Replacement Metal Gate (RMG) MOSFETs. In particular, we investigate various gate metal stacks and assess the influence of several defect passivation techniques, including novel ones developed for low thermal budget (T <450°C) RMG fabrication. We find that using a TiN p-type gate metal increases noise in nMOSFETs, while the noise of pMOSFETs is largely unaffected by the gate metal. Various defect passivation methods fail to reduce noise in high VT nMOSFETs, likely due to surface potential affecting the interface defect passivation efficiency during post-metallization annealing. Experiments with gradual modulation of the gate metal work function further support this hypothesis, offering new insights for process integration.