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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E} _{\text {eff}}^{-{2}}$ </tex-math></inline-formula> dependence is confirmed for the hole mobility in Ge-OI pMOSFETs, while the electron mobility exhibits an unusually strong dependence on <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E} _{\text {eff}}$ </tex-math></inline-formula> (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\propto {E} _{\text {eff}}^{-{4}}\text {)}$ </tex-math></inline-formula>. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu _{\text {ph}}$ </tex-math></inline-formula> exhibits an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E} _{\text {eff}}^{\,{-{0}.{3}}}$ </tex-math></inline-formula> dependence for both holes and electrons, along with a temperature dependence of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim {T} ^{\,{-{1}.{8}}}$ </tex-math></inline-formula>. The <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu _{\text {total}}$ </tex-math></inline-formula> is measured at different depletion layer carrier densities (<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${N} _{\text {depl}}\text {)}$ </tex-math></inline-formula>, revealing that <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu _{\text {Coulomb}}$ </tex-math></inline-formula> increases with the rise of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${N} _{\text {depl}}$ </tex-math></inline-formula>. Specially, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu _{\text {Coulomb}}$ </tex-math></inline-formula> exhibits <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${N} _{\text {depl}}^{{0}.{5}}$ </tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${N} _{\text {depl}}^{{1}.{8}}$ </tex-math></inline-formula> 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.