Probe microscope and measuring method using probe microscope

A probe microscope comprising:

• an electroconductive probe device;
• a contact electrification mechanism for bringing the electroconductive probe device into contact with a surface of a sample and applying a voltage between the electroconductive probe device and the sample to induce electrification on the surface of the sample;
• a potential measuring mechanism for bringing the electroconductive probe device close to the surface of the sample in a non-contact state to measure a surface potential of the sample,
• wherein the electrification of the surface of the sample by the contact electrification mechanism and the measurement of the surface potential by the potential measuring mechanism alternate at a predetermined period while the voltage applied between the electroconductive probe device and the sample at a time of the contact is sequentially changed on a per-cycle basis;
• and
• a probe device control mechanism for controlling the electroconductive probe device, wherein the probe device control mechanism comprises a displacement detection unit for detecting movement of the probe device, and an interval control unit for controlling a distance between a tip end of the probe device and the surface of the sample based on the movement of the probe, and
• wherein the interval control unit comprises a control system using an amplitude shift detecting method.

A method of measuring a surface potential of a sample by a probe microscope, comprising:

• bringing an electroconductive probe device into contact with a surface of the sample and applying a voltage between the electroconductive probe device and the sample to induce electrification on the surface of the sample;
• bringing the electroconductive probe device close to the surface of the sample to measure the surface potential of the sample,
• wherein while the voltage applied at a time of the contact is sequentially changed on a per-cycle basis, the induction of the electrification on the surface of the sample and the measurement of the surface potential of the sample alternate at a predetermined period to determine a correlation between the voltage applied at the time of the contact and the surface potential of the sample;
• and
• determining the electronic state density on the surface of the sample by assuming that the measured correlation between the voltage applied at the time of the contact and the surface potential of the sample is related to a correlation between an electron energy and an electronic state density on the surface of the sample.