Electro-Thermal Performance Boosting in Stacked Si Gate-all-Around Nanosheet FET With Engineered Source/Drain Contacts

In this article, we investigate the electro-thermal (ET) performance of stacked Si gate-all-around (GAA) nanosheet FET (NSHFET) by adopting the metal (M0) source/drain (S/D) engineered contacts such as M0-wrap around the Si S/D epitaxial regions and M0 filling through S/D trenched regions in addition to the conventional scheme where metal (M0) epi on the S/D. The device ET performance is enhanced by increasing the device on-state current (I
_ON
) by more than 10% with better device lattice heat removal from the hot-spot location of the NSHFET. This results in decreased device self-heating by lowering lattice hot-spot temperature (T
_{L, max}
) and device effective thermal resistance (R
_{th, eff}
) by more than 11% compared to conventional M0-epi-based NSHFET design. The junction temperature difference between the nanosheet channels is also lowered, which decreases the inter-sheet threshold voltage (V
_T
) difference. The benchmarking study of the device designs reveals that M0-trench-based NSHFET gives the best performance from both electrical and thermal perspective for future sub-5-nm CMOS logic technologies.