Design of a novel double doping polysilicon gate MOSFET

In this paper, a novel design of the double doping polysilicon gate MOSFET device is proposed, which has a p+ buried layer near the drain, and relatively thicker D-gate oxide film (DDPGPD MOSFET). The detailed fabrication process for this device is designed using process simulation software called TSUPREM, and the device structure plan is further used in MEDICI simulation. The effect of gate doping concentration is investigated, and it is found that the device V_th is only influenced by the S-gate; furthermore, the device can get a larger driving current by increasing the doping concentration of D-gate. Compared to other conventional DDPG MOSFETs, the short-channel effects (SCEs) including the off-state current, the gate leakage current and the drain induced barrier lowering effect (DIBL) can be effectively suppressed by the p+ buried layer and thicker D-gate oxide film. Additionally, the other parameters of the device such as the driving current are not seriously affected by the proposed design modifications.