SEM image of a TGXYZ grating
Calibration gratings from the TGXYZ series are arrays of different structures comprising rectangular SiO2 steps on a Si wafer. The small square in the center with dimensions 500 µm by 500 µm includes circular pillars and holes, as well as lines in the X- and Y- direction with a pitch of 5 µm. The large square with dimensions 1mm by 1mm contains square pillars and holes with a pitch of 10 µm. The step height value is calibrated over the whole active area. The actual step height, indicated on the individual unit label, may differ slightly from the nominal value.
The TGXYZ calibration gratings are intended for vertical and lateral calibration of SPM scanners. One can compensate for vertical non-linearity by using several calibration gratings with different nominal step heights.
SEM image of a TGX grating
SEM image of the TGX surface structures.
The silicon calibration grating from the TGX series is an array of square holes with sharp undercut edges formed by the (110) crystallographic planes of silicon. The typical radius of the edges is less than 5 nm.
Schematic of the TGX grating structures
The TGX calibration gratings are intended for lateral calibration of SPM scanners. They can also be used for:
detection of lateral non-linearity, hysteresis, creep, and cross-coupling effects
determination of the tip aspect ratio