Characterization of the silicon on insulator film in bonded wafers by high resolution X-ray diffraction

Abstract

High resolution X-ray diffraction (HRXRD) is proposed as a nondestructive tool for the characterization of the silicon on insulator (SOI) film in bonded wafers. It is demonstrated that HRXRD is capable of accurately measuring the film thickness, the tilt of the film planes with respect to the substrate planes, and the rotation misalignment of the bonded film with respect to the carrier substrate. SOI films with thicknesses down to 30 nm were readily measured with accuracy better than 1%. It is shown that an angular separation between the layer and the substrate diffraction peaks is maintained due to an unintentional miscut. Calculated diffraction spectra based on the kinematic approach showed excellent agreement with the measured diffraction.