Impact of Aluminum Ion Implantation on the Low Frequency Noise Characteristics of Hf-Based High- /Metal Gate pMOSFETs

The impact of aluminum ion implantation (Al I/I) on the 1/f noise and random telegraph noise (RTN) characteristics of high-k/metal gate (HK/MG) pMOSFETs is investigated. The Al I/I technology was implemented to tune the effective work function (EWF) of pMOSFETs without increasing the equivalent oxide thickness and complicating the process. The RTN and 1/f noise results showed that irrespective of the implanted dose, the HK/MG devices with Al I/I still exhibit lower slow oxide trap densities for the control device, because the Al filled the defect and formed a thin Al₂O₃ layer. In addition, for the HK/MG devices with different implanted doses, no significant differences in the trap properties are noted. However, the modulated EWF can be attributed to the Al I/I-induced dipoles at the HfO₂/SiO₂ interface.