The performance of p-type nanosheet FETs (NSFETs) with embedded SiGe (eSiGe) source/drain (S/D) is investigated by solving the subband Boltzmann transport equation (SBTE), highlighting three detrimental effects of aggressive scaling: 1) insufficient extension doping; 2) stress relaxation during the merging of epitaxial growth fronts; and 3) interface trap density (Dit) at the Si/SiN interfaces. An optimal doping window of the first epitaxial layer (L1) between 5 × 10^19 and 2 × 10^20 cm−3 is identified to maintain gate-controlled operation. Below this range, the device enters the injection-limited transport regime, where stress relaxation and Dit-induced injection barriers are significantly amplified, leading to pronounced performance degradation. These results highlight the critical role of L1 doping optimization for effective stress engineering and Dit mitigation, and underscore the necessity of non-equilibrium transport modeling for highly-scaled NSFETs.
Publication date: 21 July 2026
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