Scanning probe microscope

• US 8,321,960 B2
• Filed: 01/24/2008
• Issued: 11/27/2012
• Est. Priority Date: 01/24/2008
• Status: Expired due to Fees

• Current Assignee: Shimadzu Corporation
• Original Assignee: Shimadzu Corporation
• Inventors: Ito, Takeshi
• Primary Examiner(s): LOGIE, MICHAEL J
• Application Number:
  US12/864,491
• Publication Number:
  US 20110113515A1
• Time in Patent Office: 1,769 Days
• Field of Search: 250/306, 850/1, 850/4, 850/5, 850/6, 850/8, 850/10, 850/11, 850/19
• US Class Current: 850/5
• CPC Class Codes: G01Q 20/02 by optical means
• CPC Class Codes: G01Q 30/06 for error compensation

Abstract

A portion of light emitted from a laser source (11) for detecting a displacement of a cantilever (4) is extracted by a half mirror (20) and guided onto a photodetector (21) having a light-receiving surface divided into four sections. When the direction of the emitted light is inclined due to a change in the ambient temperature or other factors, the light spot formed on the light-receiving surface of the photodetector (21) moves. Accordingly, the amount and direction of the inclination of the emission direction can be recognized from the amount and direction of the movement of the light spot. A drive amount calculator (22) calculates a drive amount according to the amount and direction of the inclination, and operates an actuator (23) to rotate the laser source (11) around each of the Y and Z axes. This operation compensates for the inclination of the direction of the emitted light and thereby prevents the inclination from being falsely recognized as an irregularity on the sample surface.

Claims

1. A scanning probe microscope including:

a flexible cantilever provided with a probe;

a light source for casting an illuminating light on the cantilever; and

a detector for detecting light reflected from the illuminated cantilever, a displacement of the cantilever being determined based on position information of the reflected light obtained by the detector while the probe is scanning a surface of a sample, and the scanning probe microscope being characterized by comprising;

a) a light-splitting means for extracting a separate beam of light on a path of the illuminating light from the light source to the cantilever;

b) a light-detecting means for detecting an arrival position of the beam of light extracted by the light-splitting means; and

c) a compensating means for recognizing a change in an emission angle of the light emitted from the light source according to information obtained with the light-detecting means, and for correcting, according to a magnitude of the aforementioned change, either the position information of the reflected light or data reflecting an irregularity or physical property of the sample surface obtained based on the position information.