US 5,847,383 A · Approaching device of scanning probe microscope

Abstract

Light is reflected from a cantilever, and the reflected light, except that part which is reflected from the back of the cantilever, is applied to a light-receiving device. A distance between the probe of the cantilever and a sample is determined in accordance with changes in the light in order to protect both the sample and the probe and to shorten the time the probe requires to reach the sample. The probe is moved toward the sample at high speed until the probe reaches a point close to the sample. A mechanism is provided which detects changes in a probe-displacement signal representing the displacement of the probe. A differentiation section provided in the mechanism differentiates the probe-displacement signal and generates a signal. The signal is supplied to a threshold determination section, which determines whether or not the output signal of the differentiation section exceeds a predetermined threshold value. When the signal is found to exceed the threshold value, an approaching interruption section generates an interruption command, which is supplied to a motor driver, stopping, a motor. As a result, a coarse adjustment mechanism stops moving the prove toward the sample. A voltage at a predetermined level is then immediately applied to a piezoelectric member, causing the piezoelectric member to contract in the Z direction, thereby moving the probe away from the sample.

Claims25

Dependent claims

An approaching device of a scanning probe microscope comprising:

a probe disposed opposite to a sample;
a cantilever having a proximal end portion and a free end portion which holds said probe;
scanning means for relatively moving said probe and said sample;
displacement detection means for optically detecting displacement of said cantilever caused by a force acting between said probe and said sample, said displacement detection means including a light source for irradiating said cantilever with a laser beam and light detection means for detecting a light beam reflected by said cantilever;
approaching means for relatively changing a distance between said probe and said sample so as to cause said probe and said sample to approach each other;
sample reflection light detection means for detecting sample reflection light which is produced by the laser beam when the laser beam reaches said sample and is reflected by a surface of said sample;
and
movement-speed switch means for switching a movement speed of said approaching means in accordance with an output signal output by said sample reflection light detection means.

5 more elements

An approaching device of a scanning probe microscope comprising:

a probe disposed opposite a sample;
a cantilever having a free end portion which holds the probe;
a scanning mechanism for relatively moving the probe and the sample;
a rough adjustment mechanism which is movable to relatively change a distance between the probe and the sample so as to cause the probe and the sample to approach each other;
a light source arranged to emit a laser beam which reaches the cantilever and which is reflected by the cantilever to produce cantilever reflection light;
a light receiving device, provided on an opposite side of the sample with respect to the cantilever, for detecting, based on the cantilever reflection light, displacement of the cantilever caused by a force acting between the probe and the sample, and for detecting sample reflection light which is produced by the laser beam when the laser beam reaches the sample and is reflected by a surface of the sample;
and
a movement interruption section for detecting, based on a change in a light output signal output by the light receiving device, a contact point of the probe and the sample as the probe and the sample are moved closer to each other by the rough adjustment mechanism, and for interrupting a movement of the rough adjustment mechanism approximately at the contact point.

5 more elements

An approaching device of a scanning probe microscope comprising:

a probe disposed opposite a sample;
a cantilever having a free end portion which holds the probe;
a scanning mechanism for relatively moving the probe and the sample;
a rough adjustment mechanism which is movable to relatively change a distance between the probe and the sample so as to cause the probe and the sample to approach each other;
a light source arranged to emit a laser beam which reaches the cantilever and which is reflected by the cantilever to produce cantilever reflection light;
a light receiving device, provided on an opposite side of the sample with respect to the cantilever, for detecting, based on the cantilever reflection light, displacement of the cantilever caused by a force acting between the probe and the sample, and for detecting sample reflection light which is produced by the laser beam when the laser beam reaches the sample and is reflected upon a surface of the sample;
and
a movement-speed switch section for reducing, based on an output signal output by the light receiving device, a movement speed of the rough adjustment mechanism before the probe and the sample are brought into contact with each other;
and
a movement interruption section for interrupting a movement of the probe and the sample as the probe and the sample are being moved closer to each other at the reduced movement speed based on the output signal output by the light receiving device, said movement interruption section detecting a positional relationship of the probe and the sample based on the output signal output by the light receiving device and interrupting a movement of the rough adjustment mechanism at a targeted contact point.

7 more elements

An approaching device of a scanning probe microscope comprising:

a probe disposed opposite a sample;
a cantilever having a free end portion which holds the probe;
a scanning mechanism for relatively moving the probe and the sample;
a rough adjustment mechanism which is movable to relatively change a distance between the probe and the sample so as to cause the probe and the sample to approach each other;
a displacement detecting section for detecting displacement of the cantilever caused due to a force acting between the probe and the sample;
a distance detecting sensor for detecting a change in the distance between the probe and the sample caused in accordance with a movement of the rough adjustment mechanism;
and
a movement-speed switch section for reducing, based on an output signal output by the distance detecting sensor, an approach speed of the probe and the sample which is determined by the movement of the rough adjustment mechanism before the probe and the sample are brought into contact.

5 more elements

Dependencies are inferred from the claim text.

Approaching device of scanning probe microscope

Life of this patent

Approaching device of scanning probe microscope

Life of this patent

Abstract

Claims25