Calibration

This section provides detailed instructions for the fine calibration of the Dimension Icon SPM. In general the scanner’s calibration should be checked every three months. The main change in calibration will be the loss of piezo sensitivity in the first year of use. This is an expected behavior; loss of 10–15% of the initial scan size is common.

Bruker employs a software-guided calibration procedure for all microscopes. The procedural details of how calibration is executed using NanoScope software are beyond the scope of this User Guide and include proprietary methods exclusive to Bruker. The calibration is summarized in four basic steps outlined below.

1. Orthogonality Adjustments: The orthogonality adjustment compensates for a possible non-square scan pattern.
2. Scanner Linearization: Adjust parameters for correcting the capacitive nature of the piezo material and force the XY motion of the piezo to move at a constant velocity.
3. XY Calibration: Designate the software conversion values using one or both of the following methods.
   • Capture Calibration and Auto calibration: A built-in software routine automatically controls the scanner while capturing a series of data files. The data files are then used to “teach” the software the actual distance that the scanner moved. This process creates a customized set of conversion values that will be used to convert the known signals to a metric scale.

   -OR-

   • Fine Tuning: Manually test and adjust XY sensitivity and derating values to within 1% accuracy. The conversion values that scale the scanner motion are confirmed, or are adjusted if necessary to within 1%. These same values should be adjusted by the customer as the scanner ages due to use. A scanner will typically lose 10-20% of its scan range over the first year of typical use. The scanner will then become stable as long as it is not damaged.
4. Calibrate Z: Calibrate the Z scan tube to within 2%. A separate calibration “look-up” table stores the conversion values for converting the control voltages applied to the Z tube. These values are determined by scanning over a sample with a known depth.

Bruker recommends that you adhere to the Calibration schedule shown in table 1. After initial installation, perform the Fine-tuning for XY Calibration per the following time schedule. If you find that the calibration measurements are more than 10% off at any point during Fine-Tuning Calibration, stop and perform the full XY calibration routine (Capture Calibration). For most applications it is sufficient to perform the Z calibration with the same frequency. For critical height measurements Bruker recommends monthly Z calibration.

Table 1: Recommended calibration schedule

Depending on your application or the amount of time your system has been in use, you may need to run through one or more of the various Calibration Procedures to ensure optimal functioning of your Dimension Icon.

Open topic with navigation