Use of X-Ray Techniques for In-Line Control of Epitaxial Layers in Advanced FDSOI Technology

摘要

This paper describes specific applications illustrating the use of high resolution X-ray diffraction (HRXRD) for the inline control of epitaxial films for advanced logic technology nodes. More specifically, an innovative strategy based on HRXRD rocking-curve analysis is described for the control of epitaxial SiGe and SiC layers on fully depleted silicon on insulator wafers. This includes consideration in the strategy for managing the tilt between the SOI layer and the bulk silicon substrate. The robustness of such approach is demonstrated for specific use cases. The benefit of combining HRXRD and X-ray reflectometry techniques is also illustrated specifically for the application of Ge composition measurement of ultrathin SiGe films (<;10 nm). Finally, examples of HRXRD reciprocal space maps obtained in an industrial environment is demonstrated for the case of both SiGe and SiC materials embedded in periodical structures.