Second harmonic generation for contactless non-destructive characterization of silicon on insulator wafers

Abstract

In this work we investigate a non-invasive, non-destructive characterization technique for monitoring the quality of film, oxide and interfaces in silicon-on-insulator (SOI) wafers. This technique is based on optical second harmonic generation (SHG). The principles of SHG and the experimental setup will be thoroughly described. The experimental parameters best suited for testing SOI wafers with SHG are identified. SOI geometry, as well as the passivation of the top surface, both have an impact on the observed SHG signal. The back-gate bias applied on the substrate is shown to modulate the SHG signal.

Second Harmonic Generation characterization of SOI wafers: Impact of layer thickness and interface electric field

“…In a material stack like SOI, the second harmonic is generated at different interfaces between Si and SiO2 [3,4], where the inversion symmetry is broken due to lattice mismatch and the presence of electric fields. It has already been shown [5] that the Si layer thickness can critically impact the SHG response through the absorption of the fundamental and second harmonic (SH) frequencies. Fig.…”