Novel GAA Si Nanowire p-MOSFETs With Excellent Short-Channel Effect Immunity via an Advanced Forming Process

In this letter, Gate-All-Around (GAA) nanowire (NW) p-MOSFETs with new approaches to fabricate totally isolated channels in replacement metal gate (RMG) are reported for the first time. Few reformed fin forming processes based on conventional high-
k
/metal gate FinFET flow are implemented to fabricate the GAA devices. Two profiles of NW channels, such as circular and inverted droplet, were fabricated by H
₂
baking and oxidation methods in the RMG process. The proposed methods would increase the process thermal budget and improve film quality for the NW channels. Providing both structural and process advantages, the optimized devices with
$L_{g} = 16$
nm demonstrate superb short-channel effect (SCE) immunity characteristics, with SS = 61.86$ mV/dec and DIBL = 6.5 mV/V for the inverted droplet NW device; these results are very close to the ideal limits of MOSFETs. The results also indicate that the inverted droplet NW devices have a slightly better SCE control than the circular NWs of similar geometric size.