Comprehensive Strain Study of Monolithic Nanosheet CFETs
Journal
IEEE Transactions on Electron Devices
Journal Volume
73
Journal Issue
7
Start Page
4233
End Page
4240
ISSN
0018-9383
1557-9646
Date Issued
2026-07-01
Author(s)
Abstract
The step-by-step evolution of strainxx along the current direction of monolithic nanosheet (NS) complementary FET (CFET) is studied through finite element analysis (FEA). The defective merge of source/drain regrowth is modeled by an air gap, while the defect-free merge of S/D regrowth is modeled by seamless S/D. After channel release, the bottom Si0.8 Ge0.2 pFET with seamless Si0.6 Ge0.4 S/D is compressively strained, while the top Si nFET with seamed Si:P (3× 1021 cm-3) S/D is also slightly compressively strained due to inward bending of Si:P S/D regrowth. Seamless Si:P/Si0.95 C0.05 and seamed Si0.8 Ge0.2 S/D can provide the desired tensile strainxx to top nFETs to boost mobility. The seamless Si:P and seamless Si0.6 Ge0.4 S/D of nFET and pFET, respectively, can provide strain-enhanced mobility and uniform inter-NS strain regardless of the n on p or p on n placement.
Subjects
Finite element analysis (FEA)
monolithic 3-D
nanosheet (NS) complementary FETs (CFETs)
SiGe
strain
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Type
journal article