Photoreflectance Spectroscopic Characterization of Si with SiO2 and HfO2 Dielectric Layers

Photoreflectance (PR) spectroscopy is employed as a non‐destructive and contactless technique for the characterization of silicon with SiO2 and HfO2 dielectric layers. The position of PR spectra reveals the critical point energy and the magnitude indicates the surface potential in silicon. By fitting PR spectra to a third‐derivative functional form, we find the critical point of silicon with a 1.0 nm SiO2 layer is 3.42 eV. The PR magnitude of samples with HfO2 dielectric layer decreases with layer thickness. This indicates the decreasing of surface potential with high‐κ layer thickness, possibly due to increased charge defects in the layer.