The Short Channel and Quantum Confinement Effects on Transfer Characteristics of Si NWMOSFET Depending on the Gate Length and Temperature

Abstract

With advancements in nanomaterial synthesis, semiconductor device technology entered a new era with nanotechnology. In fact, quantum effects such as confinement and tunneling have played a significant role in device characteristics. In this work, we have investigated quantum ballistic transport properties of Si nanowire MOSFET (Si NWMOSFET) with 4 nm gate length. Since gate length is shorter than the electron wavelength in our Si NWMOSFET, ballistic transport in one dimension (1D) is expected to be the dominant mechanism for carrier transport. Therefore, the parameters which are crucial for efficient MOSFET operation such as gate length, temperature, gate voltage have been simulated using the density gradient method to present quantum confinement effect on device transfer characteristics. We have found that Si NWMOSFET has an I_on/I_off ratio > 10^8, which is close to ideal value for similar nano MOSFETs. Moreover, due to short channel, intersubband scattering can deteriorate 1D ballistic transport properties of Si NWMOSFET, especially in low temperatures.