| Popis: |
The analysis of scattering test results often raises questions of whether facility or sample anisotropy is responsible for variation in data. The sample may appear macro-scopically isotropic yet, as in the case of a Si wafer, may affect results due to its crystal cleavage or orientation relative to observation direction. In addition, there may be point-to-point variation in sample surface characteristics leading to slightly different results depending on beam size or position tested. The relevance of these considerations can best be assessed when all parameters are tested in a matrix-like study. Other data which affect scatter are: Surface contamination, ellipsometry (depolarization effects), and surface profilometry (roughness). The scatter-test matrix (in addition to contamination ellipsometry, and profilometry data) for a 6.0 inch diameter wafer includes: Beam size (1.0, 2.0 and 5.0 inches), beam polarization (vertical vs horizontal), sample cleavage axis orientation with re-spect to detector sweep plane (perpendicular vs parallel), and beam band-width (full xenon arc vs 100 Angstroms wide and peaked at 5000 Angstroms). Similar tests were performed (except with the 5.0 inch beam) with 5.0 inch samples cleaved at (1,0,0) and (5,1,1) crystal orientations. |
