Vibration distortion removal for scanning probe microscopes

An apparatus comprising;

• a vacuum chamber;
• a support disposed on a bottom of the vacuum chamber;
• a sample holder disposed on the support;
• a probe and piezo tube assembly disposed in the vacuum chamber for scanning surface features of a sample;
• an interferometer disposed in the vacuum chamber wherein the interferometer measures a distance between the sample and a point fixed with respect to the sample;
• and
• a data processor connected to the probe and piezo tube assembly and the interferometer;
• wherein the interferometer comprises a laser, a beam splitter, first and second mirrors and a detector;
• and
• wherein a light beam emitted by the laser is split by the beam splitter into paths 11 and 13;
• a light beam passing along path 11 is directed to the first mirror and reflected along path d to the sample where it is reflected off the sample back to the first mirror and back along path 11 to the beam splitter where it is split into a first part and a second part;
• the first part follows path 12 to a second mirror where the first part is reflected back to the beam splitter and then along path 13 to the detector;
• the second part is isolated from the laser;
• at the beam splitter the first part rejoins a part of the light beam directly emitted by the laser that follows path 13 to the detector where the first part and the part of the light beam directly emitted by the laser interfere.

A method for improving images of surface features of a sample, constructed by a scanning probe microscope, comprising:

• constructing images of surface features of a sample with a scanning probe microscope;
• measuring a displacement of the sample that occurs during the constructing step;
• and
• correcting the images using the measured displacement;
• wherein the displacement is measured using an interferometer;
• and
• wherein the measuring step comprises:
• emitting a light beam from a laser;
• splitting the light beam into paths 11 and 13;
• passing a portion of the light beam along path 11 to a first mirror and reflecting it along a path d to the sample where it is reflected off the sample back to the first mirror and then back along path 11 to the beam splitter;
• then
• splitting the portion of the light beam into a first part and a second part;
• the first part following path 12 to a second mirror where it is reflected back to the beam splitter and then along path 13 to the detector;
• isolating the second part of the portion of the light beam from the laser;
• and
• at the beam splitter, combining the first part of the portion of the light beam with another portion of the light beam directly emitted by the laser that follows path 13 to the detector where the first part and the another portion of the light beam directly emitted by the laser interfere.