Channel Doping Concentration Influence on BESOI MOSFET Light Sensor

Abstract

The BESOI (Back Enhanced SOI) MOSFET is a new device that was developed and fabricated at the University of Sao Paulo in 2015. Its main advantages are the reconfigurable behavior, i.e., can work both like P- and N-type transistor depending only of the back gate bias, and fabrication simplicity. This paper studies the influence of channel doping concentration on the sensitivity of BESOI MOSFET used as a light sensor. The light sensitivity is investigated for different doping elements (boron and phosphorus) and it is shown that one impurity is more suited for a certain operation mode, i.e., pMOS and nMOS. An optimal doping concentration for better light sensitivity is obtained, resulting in $10^{\mathbf{17}} \mathbf{cm} ^{\mathbf{-3}}$ of boron for p-type $(V_{\mathbf{GB}} \lt \lt 0)$ and the same level of phosphorus for n-type $(V_{\mathbf{GB}} \gt \gt 0)$ BESOI MOSFET.