Impact of self-heating effects on nanoscale Ge p-channel FinFETs with Si substrate

In this paper, self-heating effects (SHE) in nanoscale Ge p-channel FinFETs with Si substrate are evaluated by TCAD simulation. Hydrodynamic transport with modified mobilities and Fourier's law of heat conduction with modified thermal conductivities are used in the simulation. Ge p-channel single-fin FinFET devices with different S/D extension lengths and fin heights, and multi-fin FinFETs with different fin numbers and fin pitches are successively investigated. Boundary thermal resistances at source, drain and gate contacts are set to 2000 mu m(2)K/W and the substrate thermal boundary condition is set to 300 K so that the source and drain heat dissipation paths are the first two heat dissipation paths. The results are listed below: (i) 14 nm Ge p-channel single-fin FinFETs with a 47 nm fin pitch experience 9.7% on-state current degradation. (ii) Considering the same input power, FinFETs with a longer S/D extension length show a higher lattice temperature and a larger on-state current degradation. (iii) Considering the same input power, FinFETs with a taller fin height show a higher lattice temperature. (iv) The temperature in multi-fin FinFET devices will first increase then saturate with the increasing fin number. At last, thermal resistances in Ge p-channel single-fin FinFETs and multi-fin FinFETs are investigated.