Properties of Accumulation-Mode Multi-Gate Field-Effect Transistors

In this work, we analyze the conduction mechanisms and the electrical performance of intrinsic and doped accumulation-mode (AM) p-type, triple-gate silicon-on-insulator (SOI) metal oxide semiconductor field-effect transistors (MOSFETs). Both long- and short-channel devices with different fin widths are investigated on the basis of experimental and simulation data. The analysis shows that for a small fin width, the threshold voltages associated with both body current and side channels in heavily doped devices coincide, thereby preventing the increase in leakage current caused by body conduction that is conventionally observed in planar AM fully-depleted (FD) SOI MOSFETs. Short-channel effects (SCEs) are minimized in these devices owing to the good electrostatic control by the surrounding gate. The experimental data indicate that SCEs are comparable to those observed in inversion-mode (IM) devices with a gate length of 50 nm. This makes AM triple-gate (or more generally, multigate) MOSFETs interesting devices for digital applications. (C) 2009 The Japan Society of Applied Physics