JPH01224603A - Wide-range scanning type tunnel microscope - Google Patents

Abstract

PURPOSE:To expand the scanning range of a probe by providing the probe atop of a swing arm which is supported at one corner through an elastic hinge and driving it finely. CONSTITUTION:An actuator 3 provided on a fixed part 1 consisting of a piezoelectric element is driven by an actuator driver 14 for scanning to drive the swing arm 2 provided to the fixed part 11 through the elastic hinge 1. Then the arm 2 enters circular motion on an XY surface above the fixed part 11 about the hinge 1, and consequently the probe 20 provided to a measuring head 5 makes a scan on the surface of a sample 10. Then a voltage which is developed by converting a tunnel current by a voltage converting circuit 12 so that the voltage is constant throughout the scanning is amplified by an actuator drive 13 for the probe and applied in a Z-directional actuator in the head 5; and the driving of the probe 20 is controlled to hold the distance between the sample 10 and probe 20 constant. Here, the quantity of control over the driving of the probe 20 and the quantity of the driving of the actuator 3 are displayed 15 to measure the surface shape of the sample 10.

Description

[Detailed description of the invention] [Industrial field of application] Surface shape of substances - 1. Determination of ultrafine structure and surface properties without contact,
It also concerns a wide-range scanning tunneling microscope that can be observed using a high-resolution lens.

(Prior art) The conventional scanning tunneling microscope for this tumor was disclosed in U.S. Patent No. 434.
No. 3,993. Scanning tunnel! #11 The probe used to detect tunnel current with a microscope is a piezoelectric element (PZT) x, y, z.
A fine movement mechanism called a tri-pot that is orthogonal to the direction is generally used. That is, in the tribod shown in FIG. 6, the probe 20 has an X shape.

PZT18.1 arranged in three axis directions of Y and Z respectively
7. Base 16 via the reta actuator composed of 19
The actuator, which is fixed to the motor, has the function of converting electrical energy into kinetic energy when supplied with it. PZTs 18 and 17 in the X and Y directions scan the probe or the measurement sample, and PZTs 19 in the Z direction control the distance between the sample and the probe to obtain a tunnel 1rf flow.

(Problem to be solved by the invention) In the prior art described above, the scanning range of the probe is limited to the displacement itself of the piezoelectric element, so the scanning range is narrow (several #Lm
There was a problem called Xalm).

An object of the present invention is to provide a wide-range scanning tunneling microscope in which the scanning range of the probe is expanded.

c. Means for Solving Problems) Item 1. [In order to achieve object 1, the present invention employs the following configuration.

The probe or measurement sample micro-movement scanning mechanism includes a swing arm supported at one end via an elastic hinge, an actuator for driving the swing arm, and a tip of the swing arm for micro-movement of the probe or sample. The system uses a fine scanning mechanism consisting of a measuring head mounted on the

[Effect]

Since one end of the swing arm is supported via an elastic hinge, the arc movement of the swing arm around the elastic hinge is limited within the XY plane. By changing the position of the actuator that drives the swing arm (drive point 4),
The magnification rate of the probe movement (corresponding to the lever ratio) can be changed to α or α.

〔Example〕

1. ['Ji] is a perspective view showing a first embodiment of the present invention.

The swing arm 2 is provided integrally with the fixed part 11 via an elastic hinge l. A fixed part 111. :establish. A measurement head 5 is attached to the tip of the swing arm, and a probe 20 is attached to the head. The probe 20 is minutely driven in the Z direction by a Z direction actuator (piezoelectric element) within the head 5 . The probe 20 and the surface of the conductive sample 10 for measurement placed a on the fixed part 11 are brought close to each other so that the probe 20 flows like a tunnel flow. Tunneling occurs when a potential difference is applied between the tip and the sample.
It is sensitive to the spacing between either stream t or stream 1.

Actuator driver 14 for scanning actuator 3
When the swing arm 2 is moved in WIA by driving with scan over the surface. The tunnel current is converted into a voltage by the current-voltage conversion circuit 12 so that the tunnel current remains constant while scanning the ampoule surface, and this voltage is amplified by the probe actuator driver 13 and sent to the Z-direction actuator in the measurement head 5. In addition, the drive of the probe 20 is controlled to keep the distance between the sample IO and the probe 20 constant. The surface texture (unevenness) of the sample is measured by displaying the probe drive control mode and the drive mode of the actuator 3 on the display device 15.

FIG. 2 is a plan view of No. 11J. Using the elastic hinge l as the fulcrum of the lever, and assuming that the distance from the driving point 4 of the actuator 3 is A2 and the distance from the probe of the measuring head 5 to L is,
Circle j in the XY plane of the measurement head (probe) provided at the tip of actuator 3! lll can be changed to any size by arbitrarily changing the leverage ratio L/i. At this time, the elastic hinge 1 is displaced only by the external force in the X direction, and there is no backlash in the Y direction. Therefore, the reproducibility of the scanning trajectory of the probe 20 is extremely high. Note that it is also possible to use a structure in which the probe is fixed as shown in FIG. 1 and the sample is moved within the XY plane.

The third UA is a perspective view of the second embodiment of the present invention. 1st
In the structure shown in the perspective view of the figure.

The swing arm 2 and the swing arm 9 are integrated through an elastic hinge 6, and an actuator 7 for driving the swing arm 9 is fixed to the swing arm 2. A measurement head 5 is provided at the tip of the swing arm 9. In other words, two identical structures are connected within the X7 plane.

FIG. 4 is a plan view of FIG. 3. In FIG. 4, the elastic hinge l is used as the fulcrum of the lever, and the driving point 4 of the actuator 3 is
The distance to the tip is AX, the distance to the probe is LX, the elastic hinge 6 is used as a fulcrum, the distance to the drive point 8 of the actuator tough is Y, and the distance to the probe is LY. The circular movement of the probe provided at the tip of the swing arm 9 in the XY plane is faster in the Y direction than in the X direction embodiment.
By adding a structure similar to the one shown in the figure, the scanning range within the X7 plane is further expanded.

In the second embodiment, it is also possible to have a structure in which the positions of the measurement head 5 and the sample 10 are exchanged so that the probe is fixed and the sample is moved within the X7 plane.

In addition, 3 axes (X, Y,
(direction) interlocking function. It is also possible to carry out high-speed and precise measurement of any minute area within a wide range of surfaces by additionally arranging minute tripods, tube scanners, etc.

FIG. 5 is a perspective view [A] showing a third embodiment of the present invention. 1
This is a combination of a configuration in which the 1+11 constant head 5 is moved circularly in the X direction of the XY plane and a configuration in which the ΔIII constant sample lO is circularly moved in the Y direction in the X7 plane. That is, two identical structures are connected in the X direction.

The Z direction ΔI4 measurement head 5 is attached to the tip of the swing arm 2 to scan the sample 10 in the X direction, and since the sample 10 is located at the tip of the swing arm 9, it is scanned in the Y direction. In this third embodiment as well, it is possible to change the mounting positions of the measurement head 5 and the sample 1O to fix the probe and to create a structure in which the sample does not move.

Incidentally, the momentum of the probe in the X7 plane spreads as in the case of the second embodiment of co-melting in both the X and Y directions.

(Effects of the Invention) The simple structure using elastic hinges has no higata, and the reproducibility of the scanning locus is extremely high.

A wide range of scanning is possible due to the expanding lever structure that uses the lever principle.

Note that this fine movement scanning mechanism is not only used for primary scanning, but also has the advantage that it can also be used for precise setting of measurement positions by adding a three-axis movement function to the measurement head.

[Brief explanation of the drawing]

1 and 2 are a perspective view and a plan view of a first embodiment of the present invention. 3 and 4 are a perspective view and a plan view of a second embodiment of the present invention. FIG. 5 is a perspective view of a third embodiment of the present invention. FIG. 6 is a perspective view of a conventional tri-body structure. (Explanation of symbols of main parts)

Claims (1)

[Claims] 1. As a fine movement scanning mechanism for a probe or a measurement sample, a swing arm whose one end is supported via an elastic hinge, an actuator for driving the swing arm in the XY plane, and a tip of the swing arm. 1. A wide range scanning tunneling microscope characterized in that a fine movement scanning mechanism is used. 2. A claim characterized in that another swing arm supported by an elastic hinge at one end is connected to the tip of the swing arm of the fine movement scanning mechanism so as to move in the same plane and in a direction orthogonal to the movement of the swing arm. The scanning tunneling microscope according to item 1.