Reducing Leakage Current of Mosfets by Optimizing the Grain Size of Polysilicon Gate

The magnitude of leakage current between source and drain of metal-oxide-semiconductor field-effect transistors (MOSFETs) is a critical parameter for evaluating their performance. Generally, MOSFETs should exhibit low leakage current in off-state, which contributes to reduced power consumption and heat generation. A significant off leakage current in MOSFETs may generated due to ions inject to channel along polysilicon grain boundary in ion implant process. In this work, the polysilicon grain size of MOSFET had been optimized and the performances were fine investigated. We found that optimization can refine the grains of polysilicon gate, which effectively reduces the impact of ion implantation on channel and greatly reduced the leakage current. In summary, the modification of polysilicon grain size can give an idea to reducing leakage current in MOSFETs.