Determination of substrate doping, substrate carrier lifetime and density of surface recombination centres of MOSFETs by gate-controlled-diode measurements

Abstract

A MOSFET with source floating or drain floating or source connected to drain is similar to a gate-controlled-diode structure. In the present study, gate-controlled-diode measurement has been performed for n-channel MOSFETs at room temperature. It is shown that the doping concentration in the substrate region under the gate and the density of the generation-recombination centres at the Si/SiO2 interface can be obtained from the gate-controlled-diode measurement with source floating. In addition, the carrier lifetime in the substrate region can also be determined from the gate-controlled-diode measurement with source connected to drain. As a simple non-destructive technique, the gate-controlled-diode technique provides useful information about the regions of interest at the device level. Furthermore, it does not require special test structures, and it can be carried out for conventional MOSFETs.