Specific Process Knowledge/Characterization/Profiler: Difference between revisions
m →Equipment performance and process related parameters Dektak XTA: small update |
m →Height accuracy: edit |
||
| Line 78: | Line 78: | ||
===Height accuracy=== | ===Height accuracy=== | ||
The accuracy of the height measurement with the profiler depends on the measurement settings as well as the calibration | The accuracy of the height measurement with the profiler depends on the measurement settings as well as the instrument calibration, resolution, and measurement repeatability. | ||
Both the force setting and the scan speed is important: Too high force may compress a soft material like Al or Au or some polymers, while too low force may mean that the stylus "jumps" over features, especially if the scan speed is high. However, if the scan speed is too low and you are measuring a small step <500 nm, you may experience drift in the measurement. Of course you also must make sure the feature you are measuring is wide enough for the stylus tip to reach the bottom (see the [http://labmanager.dtu.dk/d4Show.php?id=2346&mach=304 DektakXT manual], Figure 3 for details). | Both the force setting and the scan speed is important: Too high force may compress a soft material like Al or Au or some polymers, while too low force may mean that the stylus "jumps" over features, especially if the scan speed is high. However, if the scan speed is too low and you are measuring a small step <500 nm, you may experience drift in the measurement. Of course you also must make sure the feature you are measuring is wide enough for the stylus tip to reach the bottom (see the [http://labmanager.dtu.dk/d4Show.php?id=2346&mach=304 DektakXT manual], Figure 3 for details). | ||
| Line 84: | Line 84: | ||
We calibrate the instrument with a step height calibration of 9160 Å for the 65 kÅ range and 24.865 µm for the larger ranges. The 95 % confidence intervals for the step height standards is 300 Å for the 9160 Å standard and 0.15 µm for the 24.865 µm standard. | We calibrate the instrument with a step height calibration of 9160 Å for the 65 kÅ range and 24.865 µm for the larger ranges. The 95 % confidence intervals for the step height standards is 300 Å for the 9160 Å standard and 0.15 µm for the 24.865 µm standard. | ||
Assuming ideal conditions, we can estimate the accuracy of a measurement based on the error of the calibration of the instrument combined with the error from the limits of the resolution and of the scatter of repeated measurements. The error stemming from the uncertainty on the calibration standard is much larger than the other errors. This means that the total uncertainty on a single measurement is dominated by the calibration standard uncertainty, which leads to the 95 % confidence intervals listed above in the table: just over 30 nm for the smallest range | Assuming ideal conditions, we can estimate the accuracy of a measurement based on the error of the calibration of the instrument combined with the error from the limits of the resolution and of the scatter of repeated measurements. | ||
The error stemming from the uncertainty on the calibration standard is much larger than the other errors for all ranges except the 1 mm range. This means that the total uncertainty on a single measurement is mostly dominated by the calibration standard uncertainty, which 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, where the resolution uncertainty also contributes. | |||
==Dektak 8 stylus profiler== | ==Dektak 8 stylus profiler== | ||