Contact Cavity Shaping and Selective SiGe:B Low-Temperature Epitaxy Process Solution for sub 10-9 Ω.cm2 Contact Resistivity in Nonplanar FETs

In order to tackle the CMOS contact resistance bottleneck, we developed a contact cavity shaping process that leverages a Reactive Ion Etching (RIE) technology, and a selective highly doped SiGe:B epitaxial process allowing an active boron doping level of 2E21 at.cm-3. By co-optimizing these processes in the contact module on 300mm wafers, we demonstrate a record low transistor contact resistance of 11 $\Omega.\mu$m of W
eff
with corresponding effective $\rho_{\mathrm{c}}$ of 5.2$\times 10^{-10}\Omega$.cm
²
, which translates into a device I
eff
performance gain of 44/19% (median/leading edge).