JPH0335103A - Scanning tunneling microscope - Google Patents

Abstract

PURPOSE:To easily change a probe and a sample by providing a base and a vibration eliminator, a fixing mechanism for fixing the base at a constant position, etc. CONSTITUTION:A lever 13 is pressed by a driving shaft 18 to turn around a fulcrum 13a. As this lever 13 rotates, a coupling rod 15 which is engaged between the lever 13 and the force point P of a lever turns the lever 16 around a fulcrum 16a. Consequently, cut parts 4a and 4b formed in end parts of the base 4 are pressed by pins 14 and 17 provided at the operation points of the levers. At this time, the base 4 is pressed by the pins 14 and 17 toward the bottom plate of an observation chamber 1 to press the vibration eliminator 12 arranged between the bottom plate and base 4 toward the bottom plate of the vibration eliminator 12, so the operation of the vibration eliminator 12 is suppressed and the base 4 is fixed at the constant position. Then a probe socket 6 and a sample holder 9 are changed at the position where the base 4 is fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fixing mechanism for a scanning tunneling microscope that detects tunneling current by bringing a probe close to a sample and outputs an uneven image of the sample surface.

[Prior Art] In a scanning tunneling microscope, in order to obtain atomic-level resolution of the surface of an observation sample, it is required that the shape of the tip of the probe be sharpened. Therefore, the tip of the probe is a one-atom tip, such as one atom at the tip of the probe formed by an electric field polishing method or the like.

Now, in order to obtain a tunnel current between the tip of the probe and the sample surface when observing a sample using a scanning tunneling microscope,
It is necessary to bring the distance between the tip of the probe and the sample surface to about 1 nm, but there is a possibility that the sample and the tip of the probe come into contact during the approaching operation and the atomic tip of the probe is damaged. Or the sample may be damaged. Since atomic level resolution cannot be obtained with such a probe with a damaged atomic tip, it is necessary to replace it with a normal probe. Furthermore, even if the sample is damaged, it must be replaced with a normal sample.

By the way, in the above-mentioned scanning tunneling microscope, since it is necessary to obtain resolution at the atomic level, a vibration isolator is installed between the device and the installation surface to remove vibrations from outside the device. It is located.

Therefore, when replacing the sample or the probe, the vibration isolator operates and the position of the probe and the sample fluctuate, making it extremely difficult to replace delicate probes, etc. It is considered a problem.

The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a scanning tunneling microscope in which the probe and sample can be easily exchanged.

[Means for Solving the Problems] The present invention provides a scanning tunneling microscope that detects tunneling current by bringing a probe close to a sample and driving it three-dimensionally, comprising: a base on which the scanning tunneling microscope is placed; The present invention is characterized in that it includes a vibration isolator for supporting the base between it and the bottom plate, a fixing mechanism for fixing the base at a fixed position, and a mechanism for releasing the fixation.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. 1st
The figure is an apparatus configuration diagram for explaining one embodiment of the present invention.

In FIG. 1, 1 is an observation chamber, 2 is a preliminary chamber, 3 is a gate valve, 4 is a base, 5 is a probe drive mechanism, 6 is a probe socket to which a probe 7 is fixed, 8 is a sample stage, 9 is a sample holder;
10 is a replacement rod, 11 is a chuck, 12 is a vibration isolator, 13 is a first lever, 14 is a pin, 15 is a connecting rod, 16 is a second lever, 17 is a pin, 18 is a drive shaft, 19 is a micro A shaft drive mechanism such as a meter, and 20 are springs.

The interior of the observation chamber 1 and the preliminary chamber 2 are evacuated to a high vacuum or ultra-high vacuum state by an exhaust device (not shown). Observation room 1
A base 4 is disposed on a vibration isolator 12 within the chamber, and a probe drive mechanism 5 and a sample stage 8 are disposed on the base 4. A male screw portion 5a is provided at the tip of the probe drive mechanism 5, and the probe socket 6 is screwed into the male screw portion 5a. Further, the sample stage 8 is provided with an opening 8a, and the sample holder 9 is fitted into the opening 8a. Here, when the axis connecting the probe unit and the sample during microscopy, that is, the height direction of the probe 7 and the surface of the sample S are defined as two directions (two axes), along the two axes A movable exchange rod 10 is inserted. At the tip of the exchange rod 10 is a chuck 1 that holds a sample holder and a probe socket.
1 is provided.

The replacement work of the probe socket and sample holder will be explained below.

Prior to exchanging the probe and the sample, first, the drive shaft 18 is driven in the Z direction (leftward in FIG. 1) by the shaft drive mechanism 19 such as a micrometer. By being pushed by this drive shaft 18, the first lever 13 is rotated about the fulcrum 13a of the lever. As the lever 13 rotates, the lever 1
3 and the force point P of the second lever 16, the lever 16 is rotated about the fulcrum 16a of the lever. As a result, the notches 4a and 4b provided at the ends of the base 4 are held down by the pins 14 and 17 provided at the points of action of each of the levers. At this time, the base 4 is pushed toward the bottom plate of the observation room by the pins 14 and 17, and the vibration isolator 12 placed between the bottom plate and the base 4 is also pushed toward the bottom plate. The vibration isolator 1
2 is suppressed, and the base 4 is fixed at a fixed position.

Then, the probe socket and sample holder can be replaced using the base 4.
is carried out in a fixed position.

First, when replacing the probe socket, first
The probe socket 6 held by the probe socket 6 is moved through the opening 8a of the sample stage 8 to the tip of the probe drive mechanism 5. Then, by rotating the exchange rod 10, the probe socket 6 is screwed and fixed to the male screw part 5a provided at the tip of the drive mechanism 5. After the probe socket 6 is fixed, the replacement rod 10 is pulled back to the preliminary chamber 2. Then, the gate valve provided between the observation chamber 1 and the preliminary chamber 2 is closed, and the sample holder 9 is attached to the exchange rod 10 on the preliminary chamber 2 side. After the interior of the preliminary chamber 2 is evacuated to a high vacuum or ultra-high vacuum state by an exhaust device (not shown), the gate valve 3 is opened.

Next, when replacing the sample holder, the sample holder held by the chuck 11 is moved to the opening 8a of the sample stage 8 by the exchange rod 10 and fitted into the opening 8a. The sample holder 9 is fixed to the stage 8 by a fixing mechanism (not shown) such as a fixing pin provided on the sample stage 8. Thereafter, the replacement rod 10 is pulled back to the preliminary chamber 2.

After the probe and sample have been replaced, when performing microscopy using a scanning tunneling microscope, the shaft drive mechanism 1
9 causes the drive shaft 18 to retreat toward the outside of the sample chamber. As a result, the first lever 13 is pulled back by the spring 20 provided between the first lever 13 and the sample chamber wall, and is rotated about the fulcrum 13a of the lever.

The lever 16 is also rotated about the fulcrum 16a of the lever by the connecting rod engaged with the force point P of the lever 13 and the second lever 16. As a result, the fixation of the notches 4a and 4b at the end of the base by the pins 14 and 17 is released, and the vibration isolator is activated.

[Effects of the Invention] As is clear from the above description, according to the present invention, in a scanning tunneling microscope that detects tunneling current by bringing a probe close to a sample and driving it three-dimensionally, By providing a base to be placed, a vibration isolator for supporting the base between the bottom plate, a fixing mechanism for fixing the base in a fixed position, and a mechanism for releasing the fixation. , the operation of the vibration isolator can be regulated when replacing the probe and sample. Therefore, since the position of the probe and the position of the sample are fixed, a scanning tunneling microscope is realized in which the minute probe and sample can be easily replaced.

[Brief explanation of drawings]

FIG. 1 is an apparatus configuration diagram for explaining one embodiment of the present invention. 1: Observation room 2: Preliminary room 3: Gate valve 4: Base 5: Probe drive mechanism 6: Probe socket 7: Probe
8: Sample stage 9: Sample holder 10
; Replacement rod 11: Chuck 12: Vibration isolator 13: First lever 14: Pin 15: Connecting rod 16: Second lever 17: Pin
18: Drive shaft 19: Shaft drive mechanism 20: Spring: Sample

Claims (1)

[Claims] In a scanning tunneling microscope that detects tunneling current by bringing a probe close to a sample and driving it three-dimensionally, a base plate on which the scanning tunneling microscope is placed, and a base plate 9 for supporting the base between the base plate and the base plate. A scanning tunneling microscope characterized in that it is provided with a vibration isolator, a fixing mechanism for fixing the base in a fixed position, and a mechanism for releasing the fixation.