Specific Process Knowledge/Characterization/AFM: Atomic Force Microscopy: Difference between revisions
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As the tip is worn, it will become less sharp, thus the resulting image will look blurry. | As the tip is worn, it will become less sharp, thus the resulting image will look blurry. | ||
This effect is especially visible when imaging samples with sharp/edged features, and drastically change roughness parameters like R<sub>max</sub>, R<sub>q</sub> and R<sub>a</sub>. Therefore it is important to be able to identify a worn tip. | This effect is especially visible when imaging samples with sharp/edged features, and drastically change roughness parameters like R<sub>max</sub>, R<sub>q</sub> and R<sub>a</sub>. Therefore it is important to be able to identify a worn tip. | ||
The figure below shows a comparison of the [https://www.budgetsensors.com/sample-for-tip-evaluation-tipcheck link TipCheck sample]. | |||
The left image shows a worm tip scanning across a rough surface with sharp edges. Due to tip convolution you practically use the sample to measure the shape of the tip. In this case, the tip is an oval pointing towards the top left, which causes all features to look like that. Furthermore, the worn tip is too big to reach bottom of the trenches between the structures. Which result in a lower measured roughness and Z-range. | |||
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! Image | ! Image | ||
| [[File:AFMWornTip.jpg|thumb|left|alt=Image taken using a worn probe| AFM image of the tip checker sample taken using a | | [[File:AFMWornTip.jpg|thumb|left|alt=Image taken using a worn probe| AFM image of the tip checker sample taken using a worn AFM probe]] | ||
| [[File:AFMNewTip.jpg|thumb|left|alt=Image taken using a new probe| AFM image of the tip checker sample taken using a new AFM probe]] | | [[File:AFMNewTip.jpg|thumb|left|alt=Image taken using a new probe| AFM image of the tip checker sample taken using a new AFM probe]] | ||
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Roughness information | Roughness information | ||
| | | | ||
* Scan mode: PeakForce Tapping | |||
* Probe: Tap 150Al | |||
* Size: 1µm | * Size: 1µm | ||
* Scan Speed: 1Hz | * Scan Speed: 1Hz | ||
---- | |||
* R<sub>q</sub>: 2.49 nm | * R<sub>q</sub>: 2.49 nm | ||
* R<sub>a</sub>: 1.97 nm | * R<sub>a</sub>: 1.97 nm | ||
* R<sub>max</sub>: 18.8 nm | * R<sub>max</sub>: 18.8 nm | ||
| | | | ||
* Scan mode: PeakForce Tapping | |||
* Probe: Tap 150Al | |||
* Size: 1µm | * Size: 1µm | ||
* Scan Speed: 1Hz | * Scan Speed: 1Hz | ||
---- | |||
* R<sub>q</sub>: 10.5 nm | * R<sub>q</sub>: 10.5 nm | ||
* R<sub>a</sub>: 8.45 nm | * R<sub>a</sub>: 8.45 nm | ||
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! Comments | ! Comments | ||
| The shape of the probe causes all features to look like an oval pointing towards the top left of the image. Low measured roughness as the worn tip skates across the top of the triangles. | | The shape of the probe causes all features to look like an oval pointing towards the top left of the image. Low measured roughness as the worn tip skates across the top of the triangles. | ||
| Same sample taken with a new probe. The triangular structures are pointing in different directions | | Same sample taken with a new probe. The triangular structures are pointing in different directions. Higher measured roughness as the sharper tip can map the trenches between the triangles. | ||
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''This section is written by Jesper Pan @DTU Nanolab | ''This section is written by Jesper Pan @DTU Nanolab | ||
[[Image:section under construction.jpg|150px]] | [[Image:section under construction.jpg|150px]] | ||
Section about degradation of the tip as you continue scanning | |||