Addressing Key Challenges for SiGe-pFin Technologies: Fin Integrity, Low-DIT Si-Cap-Free Gate Stack and Optimizing the Channel Strain

This paper shows the importance of oxygen control at the SiGe fin surface and within the gate stack. Optimized SiN liners are required to protect SiGe fins from oxidation during a flowable CVD (FCVD) densification anneal. Suppression of oxygen diffusion or scavenging from GeO via metal electrode is essential to achieve a low-D
_IT
SiGe gate stack. By replacing HfO
₂
with other dielectrics offering lower oxygen diffusivity, impact of metal electrode deposition process as well as the HfO
₂
nitridation is corroborated to be related to the oxygen diffusivity. Finally, when using an embedded B-doped Si
_0.4
Ge
_0.6
S/D, higher channel strain in Si
_0.7
Ge
_0.3
than in Si p-fins is obtained as predicted by TCAD.