AFM grating with trapezoid structures anisotropically etched in silicon
The TGF calibration gratings feature one-dimensional arrays of trapezoidal steps etched into a silicon substrate. The sidewalls of the structures are very smooth and planar surfaces with well-defined orientation formed by the (111) crystallographic planes in monocrystalline silicon. The sidewalls and the horizontal top surfaces form an angle of 54.74°.
|SEM image of a TGF 11 grating||Schematic of the TGF 11 grating|
|Part number||Pitch||Accuracy||Edge angle||Active area||Step height||Chip dimensions|
* Approximate value, not for vertical calibration purposes
TGF11 grating can be used for the assessment of scanner nonlinearity in the vertical direction. Direct calibration of the lateral force can be obtained by analyzing the contact response measured on the flat and sloped facets. This can be done for the calibration of conventional Si probes or cantilevers with an attached colloidal particle with any radius of curvature up to 2μm.