Strain, stress, and mechanical relaxation in fin-patterned Si/SiGe multilayers for sub-7 nm nanosheet gate-all-around device technology

Abstract

Pre-strained fin-patterned Si/SiGe multilayer structures for sub-7 nm stacked gate-all-around Si-technology transistors that have been grown onto bulk-Si, virtually relaxed SiGe, strained Silicon-On-Insulator, and compressive SiGe-On-Insulator were investigated. From strain maps with a nanometer spatial resolution obtained by transmission electron microscopy, we developed 3D quantitative numerical models describing the mechanics of the structures. While elastic interactions describe every other system reported here, the patterning on the compressive SiGe-On-Insulator substrate that is fabricated by Ge-condensation results in relaxation along the semiconductor/insulator interface, revealing a latent plasticity mechanism. As a consequence, Si layers with a uniaxial stress of 1.4 GPa are obtained, bringing fresh perspectives for strain engineering in advanced devices. These findings could be extended to other semiconductor technologies.

Precession Electron Diffraction (PED) Strain Measurements in Stacked Nanosheet Structures

“…Fig. 3 shows the finite element mechanical simulation results and good matching with PED results was obtained [2].The investigation of strain distribution in the nanosheet at various device fabrication steps will be discussed. For example, Fig.…”

State of the Art and Future Perspectives in Advanced CMOS Technology

“…There is no other testing technique that can do this. Therefore, HRXRD is an important method for the characterization of 10 nm and above nodes [ 433 , 434 , 435 , 436 , 437 , 438 , 439 , 440 , 441 , 442 ].…”

Miniaturization of CMOS

“…HRXRD is emphasized as an important tool to characterize 10-nm node and beyond. It has been demonstrated that in-line HRXRD can monitor the pre-fin and post-fin etching processes in FinFET [248]. IMEC demonstrated an in-line HRXRD set-up for analyzing composition and strain for nano-scale level devices.…”