Noncontact In-Line Monitoring of Ge Content and Thickness Variations of Epitaxial Si1-xGex Layers on Si(100) Using Polychromator-Based Multiwavelength Micro-Raman Spectroscopy

Ge content and thickness variations of epitaxial Si1-xGex layers on Si(100) were nondestructively measured using a long-focal-length, polychromator-based, multiwavelength micro-Raman spectroscopy system, which is designed for noncontact, in-line process and material property monitoring. The Ge content and thickness variations measured using the Raman system showed good agreement with results from both high-resolution X-ray diffraction (HRXRD) and secondary ion mass spectroscopy (SIMS) analysis. The nondestructive depth profiling capability of the multiwavelength Raman spectroscopy was verified on Si1-xGex layers on Si(100) intentionally profiled with a Ge content gradient. (C) 2010 The Japan Society of Applied Physics