Atomic Force Microscopy (AFM) is a high resolution technique to measure the topography of samples. However, in order for such measurements to be accurate, the AFM must be calibrated, so that the results can be trusted. The commercial materials listed here are suitable for making such calibrations of AFM instruments.
This information on AFM standards is extracted from my forthcoming book "Atomic Force Microscopy".
Please get in touch if any information is inaccurate or you know of another standard or supplier.
See appendix B of Atomic Force Microscopy for calibration procedures.
X-Y Standards
These are standards to calibrate or check linearity in the X-Y axis in SPMs.
|
Source |
Standard |
|
VLSI standards |
many in µm range (silicon, 2D) 100 to 1000 nm (silicon, 1D) |
|
Ted Pella |
144 nm (aluminium on Silicon) 300 nm (titanium on silicon) |
|
MikroMasch |
3 and 10 µm, HOPG |
|
SPI Supplies |
300 or 700 nm (metal-coated silicon) |
|
Electron Microscopy Sciences |
300 or 700 nm (metal-coated silicon) |
|
Applied NanoStructures |
Various in micrometer range (metal-coated silicon). I personally tried use these standards. |
|
Bruker |
1, 2, 10, 15 µm (silicon) |
|
NT-MDT |
278 nm (aluminium on glass, 1D) 3 µm (silicon, 2D) |
|
Asylum Research |
10 and 20 µm pitch (metal on silicon) |
|
Nanosensors |
100, 200 or 300 nm (silicon) 4, 8 and 16 µm (silicon |
|
BudgetSensors |
500 nm, 5 and 10 µm - SiO2 on silicon. |
|
Team Nanotech |
Pitch and feature width standards |
|
Geller Micro |
Geller sell references and standards (including traceable ones), suitable for AFM as well as EM. |
Z standards
Here are standards to calibrate the z scale. Sometimes these can be the same ones as used for the x-y axis calibration, but often they are separate samples.
|
Source |
Z calibration standard |
|
VLSI standards |
various silicon and quartz |
|
MikroMasch |
Various in silicon, HOPG |
|
NTT AT |
Silicon monatomic steps (0.31 nm) |
|
Ted Pella |
20, 100 and 500nm (Silicon) |
|
Applied NanoStructures |
10nm, 1µm |
|
BudgetSensors |
10, 100 and 500 nm steps - SiO2 on silicon |
|
Veeco |
2, 100, or 200 nm (silicon) |
|
NT-MDT |
Various steps in silicon and atomic steps in Silicon (0.31 nm) |
|
Asylum Research |
200 nm (metal on silicon) |
|
Nanosensors |
8nm (silicon) |
|
Silios Technologies |
2, 5 and 10 nm (silicon) 1 nm "in development" |
Other standard materials include ultraflat samples - mica and HOPG, available from various suppliers, and quartz ultraflat sample from nanosensors.
Particle Standards
Particle samples are also useful both to calibrate the tip and as height references.
|
Supplier |
Particle sample |
|
Tedpella |
Gold colloids in 5, 15, or 15 nm diameter |
|
Edmund Optics |
Polystyrene nanospheres in a range from 20 to 900 nm |
|
Evident Technology |
Quantum dots ranging from 2.2 to 5.8 nm |
|
Electron Microscopy Sciences |
Colliodal gold in 0.8 to 25 nm diameter |
LFM Standards
Samples for calibrating LFM , with fixed angle slopes are:
|
Supplier |
LFM sample |
|
Mikromasch |
Triangles (silicon), top angle 70 ° Steps with sloped edges (silicon), slopes 54 ° |
|
Edmund Optics |
Ruled diffraction gratings, with various angles |
Phase References
Samples for calibrating phase are available from Asylum Research and EMS. Both are polymer samples with regions of different hardness.
Probe Shape Calibration Samples
These are samples you can image with the AFM in order to get an in situ measurement of the radius and shape of the probe tip.
|
Supplier |
Sample |
|
Aurora NanoDevices |
Tip check sample (100 nm z-scale). Nioprobe tipcheck sample ( 10 nm z scale) |
|
Mikromasch |
Porous aluminium |
|
NT-MDT |
Silicon spikes |
|
BudgetSensors |
Thin film on silicon wafer, with sharp pyramidal spikes. I have used this sample, and it can be used in contact or oscillating modes to characterise probe tip shape. |
Feel free to get in touch with any updates / corrections.