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EP0422548A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Atomic force microscope

Assignee: Olympus Corp
•
Filing: 1990-10-08
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Granted: —
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Expires: 2010-10-08
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Abstract

Abstract A light beam (L) from a light source (12) is divided into two beams (Lr, Lt) by a polarized beam splitter (16). The beam (Lr) is reflected by a mirror (20), is converted into a P-polarized beam by a 1/4 λ plate (18), passes through the beam splitter (16), is reflected by prisms (22, 24), passes through a polarized beam splitter (26), is reflected by a mirror (30), is converted into an S-polarized beam by a 1/4 λ plate (28), is reflected by the beam splitter (26), and is finally incident on a detector (34). The beam (Lt) is converted into an S-polarized beam by a 1/2 λ plate (36), is reflected by a polarized beam splitter (38), is reflected by the upper face of a cantilever (44) sup­porting a probe (46), passes through a polarized beam splitter (52), is reflected twice in a prism (54), passes through the beam splitter (38), is reflected again by the cantilever (44), is converted into an S-­polarized beam by a 1/4 λ plate (40), is reflected by the beam splitter (52), is converted into a P-polarized beam by a 1/2 λ plate (56), passes through the beam splitter (26), and is finally incident on the detector (34). The detector (34) outputs the displacement of the cantilever (44) from the optical path difference of the beams Lr and Lt.

Inventors

  • 👤 Masahiko Kato
  • 👤 Takao Okada
  • 👤 Hiroshi Kajimura

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 04:27
CPC Classifications
G; G01; G01Q; G01Q20/00; G01Q20/02; B; B82; B82Y; B82Y35/00; Y; Y10; Y10S; Y10S977/00; Y10S977/84; Y10S977/849; Y10S977/86; Y10S977/868; Y10S977/87

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 274 words
An atomic force microscope for evaluating the surface of a sample, comprising: a probe (46) arranged close to the surface of the sample (48); a cantilever (44, 94) having one end which supports the probe (46) on one face, the cantilever (44, 94) being elastically deformable in accordance with the magnitude of an interatomic force acting between the atoms of the tip of the probe (46) and a surface portion of the sample (48); and means (51) for moving the probe relative to the surface of the sample (48); characterized by comprising: a reflecting surface mounted on that face of the cantilever (44, 94) which is opposite to the face sup­porting the probe (46); means (16, 66) for dividing a coherent light beam into two light beams; a reference mirror face (20, 30, 80, 84) formed in a vibration system in which the surface of the sample (48) is provided; means (22, 24, 72, 76) for guiding one of the two light beams to the reference mirror face (20, 30, 80 84); means (42, 76) for guiding the other light beam to the reflecting surface of the cantilever (44, 94); means (34, 90) for detecting displacement of the cantilever (44, 94) by synthesizing the light beam reflected by the reference mirror face (20, 30, 80, 84) and the light beam reflected by the reflecting surface of the cantilever (44, 94) with each other, so as to cause interference therebetween; and means for forming an image of the surface profile of the sample on the basis of a signal output from the probe-moving means (51) and a signal output from the detecting means (34, 94).
Claim 2
Dependent Claim 274 words
An atomic force microscope for evaluating the surface of a sample, comprising: a probe (46) arranged close to the surface of the sample (48); a cantilever (44, 94) having one end which supports the probe (46) on one face, the cantilever (44, 94) being elastically deformable in accordance with the magnitude of an interatomic force acting between the atoms of the tip of the probe (46) and a surface portion of the sample (48); and means (51) for moving the probe relative to the surface of the sample (48); characterized by comprising: a reflecting surface mounted on that face of the cantilever (44, 94) which is opposite to the face sup­porting the probe (46); means (16, 66) for dividing a coherent light beam into two light beams; a reference mirror face (20, 30, 80, 84) formed in a vibration system in which the surface of the sample (48) is provided; means (22, 24, 72, 76) for guiding one of the two light beams to the reference mirror face (20, 30, 80 84); means (42, 76) for guiding the other light beam to the reflecting surface of the cantilever (44, 94); means (34, 90) for detecting displacement of the cantilever (44, 94) by synthesizing the light beam reflected by the reference mirror face (20, 30, 80, 84) and the light beam reflected by the reflecting surface of the cantilever (44, 94) with each other, so as to cause interference therebetween; and means for forming an image of the surface profile of the sample on the basis of a signal output from the probe-moving means (51) and a signal output from the detecting means (34, 94).
Claim 3
Dependent Claim 177 words
An atomic force microscope for evaluating the surface of a sample, comprising: a probe (116) having a tip arranged close to the surface of the sample (48); a first cantilever (112) having one end which sup­ports the probe (116) on one face, the first cantilever (112) being elastically deformable in accordance with the magnitude of an interatomic force acting between the atoms of the tip and a surface portion of the sample (48); means for moving the probe relative to the surface of the sample (48), and first detecting means for detecting movement of the end of the first cantilever (112) and outputting a signal corresponding to the detected movement; characterized by comprising: a second cantilever (114) having a characteristic frequency equal to that of the first cantilever (112) and arranged close to the first cantilever (112); second detecting means for detecting movement of the end of the second cantilever (114) and outputting a signal corresponding to the detected movement; and means for outputting a difference between the signals output from the first and second detecting means.
Claim 4
Dependent Claim 177 words
An atomic force microscope for evaluating the surface of a sample, comprising: a probe (116) having a tip arranged close to the surface of the sample (48); a first cantilever (112) having one end which sup­ports the probe (116) on one face, the first cantilever (112) being elastically deformable in accordance with the magnitude of an interatomic force acting between the atoms of the tip and a surface portion of the sample (48); means for moving the probe relative to the surface of the sample (48), and first detecting means for detecting movement of the end of the first cantilever (112) and outputting a signal corresponding to the detected movement; characterized by comprising: a second cantilever (114) having a characteristic frequency equal to that of the first cantilever (112) and arranged close to the first cantilever (112); second detecting means for detecting movement of the end of the second cantilever (114) and outputting a signal corresponding to the detected movement; and means for outputting a difference between the signals output from the first and second detecting means.
Claim 5
Dependent Claim 113 words
An atomic force microscope according to claim 2, characterized in that at least one of said first and second detecting means includes: a conductive film (112A) formed on that face of the cantilever (112, 114) which is opposite to the face facing the sample; a tunnel tip (152, 154) supported at a position close to the conductive film (112A); means (153) for applying a bias voltage between the conductive film (112A) and the tunnel tip (152, 154), to thereby cause a tunnel current therebetween; and means (170) for detecting the tunnel current, the detecting means detecting the movement of the cantilever (112, 114) on the basis of a variation in the tunnel current.
Claim 6
Dependent Claim 90 words
An atomic force microscope according to claim 3, characterized in that said at least one detecting means further includes: means (156, 158) for supporting the tunnel tip (152, 154) such that the tunnel tip (152, 154) is moved closer to or away from the conductive film (112A); and servo means (172) for controlling the tunnel tip-­supporting means (156, 158) on the basis of the variation in the tunnel current such that the distance between the tunnel tip (152, 154) and the conductive film (112A) is maintained at a constant value.
Claim 7
Dependent Claim 78 words
An atomic force microscope according to claim 2, characterized in that at least one of said first and second detecting means includes: a reflector formed on that face of the cantilever (112, 114) which is opposite to the face facing the sample; and an optical system (120, 122, 124, 126, 128, 130, 132, 134, 136) for guiding light to the reflector and receiving the light reflected by the reflector, to detect the movement of the cantilever (112, 114).
Claim 8
Dependent Claim 87 words
An atomic force microscope according to claim 5, characterized in that: said reflector receives light incident thereon slantwise; and said optical system includes: a two-segment type photodiode (136) on which the light reflected by the reflector is incident; and a comparator (146) for out­putting a signal which corresponds to a difference between light received by one (138) of two segments of the photodiode (136) and light received by the other segment (140) of the photodiode (136) and which therefore represents the displacement of the cantilever (112, 114).

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