ANTI-REFLECTION-COATING THICKNESS MEASUREMENTS ON TEXTURED SILICON SURFACES: EVALUATION AND ACCURACY OF DIFFERENT MEASUREMENT TECHNIQUES

摘要

The accuracy and reliability of different techniques for inline quality control of antireflection coatings(ARC) on industrial relevant surfaces are analyzed and rules to improve the accuracy of the systems are derived. Forthis, four systems are compared with respect to the setup and the way of ARC thickness calculation. Raw data andmeasured thicknesses are evaluated with respect to a reference system, to identify for each surface texture the systemwhich is suited best and to identify the physical reasons for deviations. Angle-dependent simulations andmeasurements of the spectral reflectance on monocrystalline wafers with a pyramidally-etched surface reveal thatdifferent angle corrections for mc-Si and Cz-Si are required. Besides evaluating the spectral position of thereflectance minimum, a least-squares fit of the spectral reflectance of partially textured Cz-Si is presented andevaluated.