Electron-electron interaction signature peak in the substrate current versus gate voltage characteristics of n-channel silicon MOSFETs

Impact ionization at low drain voltages in n-MOSFETs was investigated employing devices with three different channel-doping profiles. We report an anomalous peak in substrate current (I/sub SUB/) versus gate voltage (VG) characteristics. It is shown that the anomalous peak can not be directly related to any high field region in the device. The measured data is interpreted based on the general nature of electron energy distribution published by Monte-Carlo simulation groups. Strong evidence is provided which suggest that the anomalous peak in ISUB versus VC, is due to electron-electron interactions.