Graded Si1−xGexstructures have been measured with good accuracy, stability and tool‐tool matching by utilizing different measurement methods in one system (Opti‐Probe®). The measurement methods utilized are (i) laser reflectivity versus angle for S and P polarization (BPR®), (ii) visible‐DUV reflectometry (BB), and (iii) spectroscopic ellipsometry (SE). An alloy dispersion model, along with a multi‐layer linear graded‐material model, were used to process the data and extract the thickness of the cap‐Si, graded and spacer Si1−xGexlayers, as well as the Ge&percent;, simultaneously. The results were found to be in agreement with subsequent SIMS analysis to within 50Å for all layers and 0.5&percent; atomic Ge&percent;. Stability and matching results for thickness were <13Å (3&sgr;) for all layers, and for the Ge&percent; the stability was <0.25–0.6&percent; (3&sgr;). © 2003 American Institute of Physics