Suppression Mechanism of Volume Shrinkage for SOG Film by Plasma Treatment

Abstract

We investigated the suppression mechanism of volume shrinkage for a spin on glass (SOG) film by plasma treatment using hard X-ray photoelectron spectroscopy, X-ray reflectometry (XRR), and UV-Raman spectroscopy. The suppression of the SOG film shrinkage was attributed to the control of N out-diffusion from the SOG film and O in-diffusion into the SOG film, which was due to the plasma treatment prior to the conventional cure annealing process. It was also confirmed from the XRR measurements that the SOG film was densified by the plasma treatment. Moreover, UV-Raman measurements were performed to evaluate the Si stress at the SiO2/Si interface that was induced during the gap filling process. The stress was controlled by the appropriate plasma treatment. Thus, we concluded that the plasma treatment was effective for the suppressions of SOG film shrinkage and stress induction and for the SOG film densification.