Scanning probe microscope with slant detection and compensation

Abstract

A scanning probe microscope comprises a probe supported by a cantilever at the end portion. The cantilever elastically deforms by force acting on the probe. During the probe is scanned along the sample surface, a displacement of the probe along a z-axis perpendicular to the sample surface and a slant of the probe with respect to the z-axis is detected by an optical system. The optical system includes a light source, a reflection surface provided on the end of the cantilever and an optical element having first through forth light receiving regions. A light beam from the light source is directed to and reflected on the reflection surface, the beam from the reflection surface is directed on the light receiving regions. The microscope further comprises a servo circuit for controlling the displacement and the slant of the cantilever to keep them constant in response to signals S.delta. and S.theta. respectively, the signal SD being a difference signal between the sum of the outputs from the first and second light receiving regions and the sum of the outputs from the third and fourth light receiving regions, and the S.theta. being a difference signal between the sum of outputs from the first and third light receiving regions and the sum of outputs from the second and fourth light receiving regions.

Dependencies are inferred from the claim text.