Specific Process Knowledge/Characterization/Profiler: Difference between revisions
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====Total uncertainty budget==== | ====Total uncertainty budget==== | ||
We can numerically estimate the accuracy of a measurement based on the error of the calibration combined with the error from the limits of the resolution and of the scatter of repeated measurements. You can | We can numerically estimate the accuracy of a measurement based on the error of the calibration combined with the error from the limits of the resolution and of the scatter of repeated measurements. You can see an uncertainty budget for the Dektak measurements here (made by Rebecca Ettlinger in 2020): [[Media:uncertainty budget dektaks.xlsx]]. It is based on the procedure described [https://www.nde-ed.org/GeneralResources/Uncertainty/Combined.htm here]. | ||
The error stemming from the uncertainty on the calibration standard dominates for all ranges except the 1 mm range, where the resolution also plays a role. This leads to the 95 % confidence intervals listed above in the table: just over 30 nm for the smallest range, about 0.17 µm for the medium ranges, and about 0.6 µm for the 1 mm range. As noted above, be aware that if you have a step height that is difficult to measure, the scatter of repeated measurements could easily lead to larger confidence intervals. | The error stemming from the uncertainty on the calibration standard dominates for all ranges except the 1 mm range, where the resolution also plays a role. This leads to the 95 % confidence intervals listed above in the table: just over 30 nm for the smallest range, about 0.17 µm for the medium ranges, and about 0.6 µm for the 1 mm range. As noted above, be aware that if you have a step height that is difficult to measure, the scatter of repeated measurements could easily lead to larger confidence intervals. | ||