Apparatus and method for measuring distance between fiducial features, such as magnetic transducers, to an accuracy of within one nanometer

A method for measuring distances between fiducial features of samples, the method comprising:

• adjusting an inclination of a precision stage to a predefined orientation relative to a device configured to acquire locations of the fiducial features of a sample in a sample holder coupled to the precision stage, the precision stage being configured to control an extent of movement of the sample along an axis for moving the sample along the axis a precise predefined distance to within an accuracy of about ±50 nanometers or better;
• instructing an x-y stage to move the sample holder to position a first fiducial feature of the sample to within ±10 micrometers or better of a predefined location in a field of view of the device,
• causing adjustment to the inclination of the sample holder for leveling the sample to be measured to bring the fiducial features of the sample concurrently into a proper position for acquisition by the device;
• instructing the device to acquire a location of the first fiducial feature;
• in response to repositioning of the sample the precise predefined distance along the axis by the precision stage, instructing the device to acquire a location of a second fiducial feature in the field of view of the device;
• computing the distance between the first fiducial feature and the second fiducial feature based on the locations to an accuracy of about ±50 nanometers or better;
• outputting the computed distance;
• and
• repeating the foregoing operations for additional samples positioned in the sample holder.