We have invented a new sensor adjacent methodology for high spatial resolution and high voltage measurement apparatus with which we are able to accomplish arbitrary voltage measurement without causing any unexpected arcing. We have introduced two new techniques, i.e. 1) continuously providing a voltage feedback to the sensor to make sure that it nullifies electric field between sensor and surface under test through the course of sensor approaching to the surface under test, 2) adjusting AC bias voltage to control the motion of cantilever to be constant although the sensor is far apart from the surface under test. We were able to successfully let the sensor approach a 500 V of surface under test without causing any arcing with keeping both DC and AC feedback system for the distance from 1,000 μm to 5 μm through adjusting AC bias voltage to the sensor from 200 Vp-p to 12 Vp-p.
Toshio Uehara, Tomoharu Saito, Jumpei Higashio, Yoshito Ashizawa, Katsuji Nakagawa, Akiyoshi Itoh, "A New Sensor Adjacent Methodology for High Spatial Resolution and High Voltage Measurement" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP27), 2011, pp 564 - 567, https://doi.org/10.2352/ISSN.2169-4451.2011.27.1.art00040_2