Body Current Optimization Using Threshold-Voltage-Adjust-Implant Engineering in ۴۵nm SOI MOSFET

In this paper, for the first time, Threshold-voltage-adjust-implant is engineered to optimize body current in ۴۵ nm Silicon-on-Insulator (SOI) MOSFET. The peak value and peak position concentration of the Gaussian implant under the gate oxide in the silicon body are varied in order to optimize the body current in SOI technology. The variations affect the devices’ threshold voltages. In order to make a fair comparison, the gate work function is changed to obtain the same threshold voltage within the entire simulated devices and operating regime. The body current is monitored while the it is swept from ۰ V to ۱.۵ V. The maximum of the body current is observed at VDS=۱.۵ V. The concentration of Threshold-voltage-adjust-implant peak value is changed from ۱.۷E۱۷ cm-۳ to ۷E۱۸ cm-۳. The peak position of the implant is varied from ۰ nm right under the gate oxide to ۲۰ nm below the gate oxide and silicon surface. It is observed that the body current is minimized at the peak value concentration of ۷E۱۷ cm-۳ and peak position of ۰ nm. This occurs by proper choice of the gate work function and gate material. The minimization of body current leads to the less requirement for the number of body contacts and smaller gate parasitic capacitance which, in turn, concludes higher operating frequency and larger fT.

کلیدواژه ها:

Threshold-voltage-adjust-implant ، unity-gain cut-off frequency ، Silicon-on-Insulator ، MOSFET