Calibration of non-vibrating contact potential difference measurements to detect surface variations that are perpendicular to the direction of sensor motion

A method of determining the contact potential difference of a surface of a material to characterize properties of the surface, comprising the steps of:

• providing a surface of a material;
• providing a contact potential difference sensor having a sensor probe tip;
• scanning the surface and contact potential difference sensor relative to one another;
• generating a first set of laterally-scanned sensor data representative of changes in contact potential difference between the sensor probe tip and the surface of the material as the sensor probe tip scans laterally relative to the surface of the material;
• generating a second set of laterally-scanned sensor data representative of changes in contact potential difference across the surface of the material, the second set of sensor data being generated by moving the contact potential difference sensor perpendicular to the direction of the laterally scanning of the first set of sensor data;
• processing the first and second set of sensor data to determine relative contact potential difference values;
• using a vibrating contact potential difference sensor to make at least one measurement of the absolute contact potential difference of the laterally-scanned surface using a vibrating contact potential difference sensor;
• and
• using the absolute contact potential difference data to calculate offsets which are added to the integrated, scaled non-vibrating relative contact potential difference data values to generate characteristic data which is representative of the contact potential difference between the sensor probe tip and all points on the laterally scanned surface, thereby characterizing properties of the surface of the material.

A semiconductor wafer prepared for use in an electronic component, at least one of the methods of processing including the steps of:

• providing a semiconductor wafer having a surface;
• providing a contact potential difference sensor having a sensor probe tip;
• scanning the surface of the semiconductor wafer and contact potential difference sensor relative to one another;
• generating laterally-scanned sensor data representative of changes in contact potential difference between the sensor probe tip and the surface of the semiconductor wafer as the sensor probe tip scans laterally relative to the surface of the semiconductor wafer;
• processing the laterally-scanned sensor data to provide relative contact potential difference values;
• using a vibrating contact potential difference sensor to make at least one measurement of the absolute contact potential difference of the laterally-scanned surface;
• and
• using the absolute contact potential difference data to calculate offsets which are added to the relative contact potential values to generate characteristic data which is representative of the contact potential difference between the sensor probe tip and all points on the laterally scanned surface, thereby characterizing properties of the surface of the semiconductor wafer.