Method for Extracting Ge Concentration of SiGe Channel FinFET Device Using Three-Dimensional Spectroscopic Ellipsometry-Optical Critical Dimension Metrology

The Ge concentration play an importion role in SiGe channel Fin-FET device. A fast, more convenient, and nondestructive analysis method, three-dimensional spectroscopic ellipsometry-optical critical dimension metrology (3D SE-OCD), is used to extract Ge concentrations of SiGe channel FinFETs. The refractive index (n) and extinction index (k) of SiGe with different Ge concentrations investigated under wavelengths λn= 370 nm and λk= 525 nm. Results show the Ge concentration of SiGe channel can be accurately measured using a 3D SE-OCD.