Comprehensive Understanding of the Mobility Scattering Mechanisms and Evaluation of the Universal Mobility in Ultra-Thin-Body Ge-OI p- and n-MOSFETs

The mobility scattering mechanisms in the ultra-thin-body (UTB) Ge-OI p- and n-MOSFETs have been systematically investigated. It is found that the
${E} _{\text {eff}}^{-{2}}$
dependence is confirmed for the hole mobility in Ge-OI pMOSFETs, while the electron mobility exhibits an unusually strong dependence on
${E} _{\text {eff}}$
(
$\propto {E} _{\text {eff}}^{-{4}}\text {)}$
. The
$\mu _{\text {ph}}$
exhibits an
${E} _{\text {eff}}^{\,{-{0}.{3}}}$
dependence for both holes and electrons, along with a temperature dependence of
$\sim {T} ^{\,{-{1}.{8}}}$
. The
$\mu _{\text {total}}$
is measured at different depletion layer carrier densities (
${N} _{\text {depl}}\text {)}$
, revealing that
$\mu _{\text {Coulomb}}$
increases with the rise of
${N} _{\text {depl}}$
. Specially,
$\mu _{\text {Coulomb}}$
exhibits
${N} _{\text {depl}}^{{0}.{5}}$
and
${N} _{\text {depl}}^{{1}.{8}}$
dependencies for electrons and holes, respectively. Consequently, more pronounced mobility degradation has been confirmed in UTB Ge-OI nMOSFETs than in UTB Ge-OI pMOSFETs. These findings suggest universal carrier scattering mechanisms for both holes and electrons in UTB Ge-OI channels, which are valuable for understanding carrier transport in thin-channel Ge devices for future advanced technology nodes.