Inspection and metrology challenges for 3 nm node devices and beyond

We report on non-destructive inspection and metrology potential of high-voltage (HV) critical dimension scanning electron microscopy (CD-SEM) for 3 nm node devices and beyond. We have demonstrated that the lateral recess depth of the buried SiGe layer can be measured by HV CD-SEM. We have simulated the SEM signal of the buried void in dielectric wall and buried SiGe residue of forksheet and have actually detected it by HV CD-SEM and verified it by EDX. We have also observed the buried voids on the boundary between 10 nm wide Ru line and TiN liner.