Specific Process Knowledge/Characterization/Profiler: Difference between revisions
→Quality control of measurement accuracy: removed qc table |
→Equipment performance and process related parameters Dektak XTA: New section on height accuracy |
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*Surface roughness on a line scan | *Surface roughness on a line scan | ||
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!style="background:silver; color:black" align="left" rowspan=" | !style="background:silver; color:black" align="left" rowspan="6" valign="top" |Performance | ||
|style="background:LightGrey; color:black"|Scan range x y | |style="background:LightGrey; color:black"|Scan range x y | ||
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1 Å, 10 Å, 80 Å or 160 Å (for ranges 65 kÅ, 655 kÅ, 5240 kÅ and 1 mm respectively) | 1 Å, 10 Å, 80 Å or 160 Å (for ranges 65 kÅ, 655 kÅ, 5240 kÅ and 1 mm respectively) | ||
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|style="background:LightGrey; color:black"|Height accuracy z (95 % confidence) | |||
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~ 300 Å for the 65 kÅ range, ~ 0.17 µm for the larger ranges ([[#Height accuracy|see below]]) | |||
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|style="background:LightGrey; color:black"|Max scan depth as a function of trench width W | |style="background:LightGrey; color:black"|Max scan depth as a function of trench width W | ||
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1.2*(W[µm]-5µm) | 1.2*(W[µm]-5µm) | ||
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!style="background:silver; color:black" align="left"|Hardware settings | !style="background:silver; color:black" align="left"|Hardware settings | ||
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===Height accuracy=== | |||
The accuracy of the height measurement with the profiler depends on the measurement settings as well as the calibration of the instrument. | |||
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). | |||
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 and about 0.17 µm for the larger ranges. | |||
==Dektak 8 stylus profiler== | ==Dektak 8 stylus profiler== | ||