Atomic force microscope and measuring head thereof

摘要

It is an object to realize a measuring head capable of maintaining high Z direction accuracy even with a measured sample having fine, complicated and very uneven pattern configuration, in an atomic force microscope. A light beam (141) of non-linear polarization is incident upon an end portion (110a) of an upper main surface of a cantilever body (110) having a probe (2). The cantilever body (110) is a polarizing plate, and its refractive index is given by tan (a Brewster's angle of the light beam (141)). Accordingly, a reflected light beam (142) reflected at the end portion (110a) becomes light of linear polarization. A light position detector (150) including an analyzing window (150a) including a polaroid thin film as an analyzing material transmits only the light oscillating in the same direction as the electric vector of the linearly polarized reflected light beam (142) to detect its positional change. A control signal (V3) for driving a piezo element (6) is generated on the basis of a value of its output signal (V1) and a measured sample (3) is scanned in the XYZ directions.