(Digital Presentation) Characterization of Passivation Dielectrics on Silicon Through Second Harmonic Generation: Effect of Fixed Charge

This paper presents the characterization of alumina passivation layers using second harmonic generation (SHG). Based on nonlinear optics, the technique has the advantage of being rapid and non-destructive, especially for thin oxide layers. For the materials under study, the SHG is sensitive to the electronic and structural properties of the interface, particularly to the interfacial electric field (Edc), and thus allowing to characterize fixed oxide charges (Qox) in the oxide and interface traps density (Dit). Time-dependent SHG (TD-SHG) is firstly used here to probe samples with various Dit and a total oxide charges (Qtot), previously extracted using corona oxide characterization of semiconductor (COCOS). The measurement conditions are adjusted to focus on the impact of the fixed charges on the SHG signal. A more detailed analysis of the SHG versus input polarization is conducted in both experiments and simulations and it shows coherent evolution tendencies with the oxide charge.