Unexpected mobility degradation for very short devices : A new challenge for CMOS scaling

Converting SOI to sSOI through Amorphization and Crystallization: Material Analysis and Device Demonstration

“…19,20 Regarding the impact of the sSOI substrate, it clearly appears that, on one hand, the electron mobility increased in nFET devices fabricated on sSOI substrates. On the other hand, pFET devices present a degraded mobility compared to reference devices.…”

The Evolution of Theory on Drain Current Saturation Mechanism of MOSFETs from the Early Days to the Present Day

“…It is first attributed to the halo implants as its contribution to the channel doping concentration increases with decreasing gate length (Romanjek et al, 2004). However, this mobility degradation is also observed in the undoped double gate MOS www.intechopen.com transistors (Cros et al, 2006) and the undoped fully-depleted silicon-on-insulator (FD-SOI) MOS transistors (Cassé et al, 2009). This indicates that the halo implant is not the dominant factor involved in the degradation.…”

“…Since the relationship between the carrier velocity and the low-field mobility is wellestablished (Khakifirooz & Antoniadis, 2006), we can have a better understanding of the apparent velocity saturation in the nanoscale MOS transistors by looking at the mobility. A strong reduction of mobility is typically observed in the silicon-based MOS transistors when the gate length is scaled (Romanjek et al, 2004;Cros et al, 2006;Cassé et al, 2009;Huet et al, 2008;Fischetti & Laux, 2001). The reason of this degradation is still not clearly understood.…”

“…This indicates that the halo implant is not the dominant factor involved in the degradation. Another limiting transport mechanism expected to be non-negligible in the short-channel MOS transistor is the presence of crystalline defects induced by S/D extension implants (Cros et al, 2006). Furthermore, Monte Carlo studies shows that ballistic transport has significant impact on the mobility degradation (Huet et al, 2008).…”

An Investigation on Effective Mobility in Nanowire FETs under Quasi-Ballistic Conditions

“…More recently, new characterization methodologies exploiting high-frequency capacitance measurements [1] as well as the magnetoresistance technique [2] made it possible to carry out accurate mobility measurements in short-channel MOSFETs, showing that carrier mobility decreases as the channel length is reduced down to 30 nm and less [3]. Electron mobility is silicon nanowire (NW) FETs has been throughly investigated in Ref.…”