JPH062120U - Fine positioning device for scanning tunneling microscope - Google Patents

Abstract

(57) [Summary] [Purpose] The probe part can be accurately aligned with the measurement point position of the device under test selected by observing with a microscope.
To provide a fine positioning device for a scanning tunneling microscope that enables easy and quick replacement of a probe portion. [Structure] A first slide table 11 and a second slide table 12 are moved with respect to a central axis of a turntable 2 on which a DUT 7 is set. 14 is mounted symmetrically so as to be movable and adjustable, and the tunnel unit 21 is attached to the first slide table 11 by the three adjusting screw portions 23.
And the operating scope 29 is installed on the second slide table 12.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fine positioning device for a scanning tunneling microscope.

[0002]

[Prior art]

 Generally, a scanning tunneling microscope observes surface roughness and atomic structure of a sample by passing a tunnel current between the sample surface and the tip of the probe. In this type of microscope, a fine positioning device is used to bring the sample surface and the tip of the probe closer until the tunnel current begins to flow. In this fine positioning device, when aligning the probe with respect to the sample up to the region where the tunnel current flows, the alignment was performed manually while checking the proximity state of the two with a microscope. Then, until the tunnel current started to flow after the probe was brought into contact with the sample, the probe was gradually and manually brought closer to the sample while monitoring the tunnel current value.

Further, since the probe may collide with the sample in the manual adjustment as described above, the probe is driven via a micrometer head as described in Japanese Utility Model Laid-Open No. 1-109169, for example. A means for automatically stopping the step motor by detecting that a tunnel current has flowed along with the step motor has come to be used.

[0004]

[Problems to be solved by the device]

 In the conventional fine positioning device for the scanning tunneling microscope as described above, no microscope with a high multiplication factor (for example, about 1000 times) is mounted, so it is not possible to confirm the selection of the measurement point position of the sample and There was a problem that the measurement point could not be freely positioned on the needle.

The present invention has been made in view of the above circumstances, and the probe part can be accurately aligned with the measurement point position of the sample selected by observing with a microscope, and the replacement work of the probe part and the sample is possible. It is an object of the present invention to provide a fine positioning device for a scanning tunnel microscope that can be easily performed.

[0006]

[Means for Solving the Problems]

 The fine positioning device of the scanning tunnel microscope of the present invention uses a tunnel unit in a scanning tunnel microscope in which an object to be tested installed on a sample table of a turntable is observed by an operating scope and measured by a tunnel unit. Mount it on the first slide table with the three adjusting screws supporting the position adjustment, install the operating scope on the second slide table, and move the first slide table and the second slide table to the feed mechanism. It is characterized in that the position can be adjusted so as to be rotationally symmetrical with respect to the center axis of the turntable by using a right-hand screw and a left-hand screw provided on the adjusting shaft portion.

[0007]

[Action]

 With the above-mentioned configuration, the turntable can be swiveled and positioned directly below the tunnel unit with the measurement point of the DUT aligned with the point defined on the monitor of the operating scope. , The probe will be properly positioned at the measurement point.

[0008]

【Example】

 An embodiment of a fine positioning device for a scanning tunnel microscope according to the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a schematic plan view of a partial cross section of a main part of the apparatus of the present example, and FIG. 2 is a schematic front view of a partial cross section of the main part.

The turntable 2 is configured so that it can be positioned at a required rotation position by rotating the table with a rotation drive mechanism. A scale plate installation base 4 and a sample base 5 are installed at predetermined positions on the turntable 2. A transparent graduation plate 6 is arranged on the graduation plate setting table 4, and an object to be tested 7 is placed on the sample table 5. Further, in the microscope main body 1, an ITV-equipped operating scope 8 having a prism is installed corresponding to the lower part of the scale plate installation base 4 in the state shown in FIG.

A pedestal 3 is mounted above the turntable 2. The gantry 3 is supported by a plurality of vertical drive mechanisms 9 and a guide support shaft 10 coaxial with the drive shaft of the turntable 2. The vertical drive mechanism 9 is composed of a screw mechanism for finely adjusting the vertical position of the gantry 3. In addition, the guide support shaft 10 is configured to maintain the shaft center position irrespective of the rotation operation of the turntable 2 and accurately move up and down along the shaft center to guide the up-and-down motion of the gantry 3.

A first slide table 11 and a second slide table 12 are mounted on the pedestal 3 as shown in FIGS. These first and second slide tables 11 and 12 are mounted on the pedestal 3 so as to be slidable in the lateral direction of the drawing. A movement adjusting mechanism 13 is attached to the first slide table 11 and the second slide table 12 so that they are moved symmetrically about the center. The movement adjusting mechanism 13 includes a feed adjusting shaft portion 14, a support portion 15 for the feed adjusting shaft portion 14, and two screw feeding mechanism portions 16.

The feed adjusting shaft portion 14 is formed by forming a left screw near the left end of the drawing, forming a right screw near the right end of the drawing, and attaching an adjusting knob 17 to the right end thereof. .

The feed adjusting shaft portion 14 rotatably supports an intermediate portion thereof by a supporting portion 15 fixed to the gantry 3. On the other hand, the screw feed mechanism portion 16 fits a screw hole formed in the moving member 18 into the right screw portion 16a of the feed adjusting shaft portion 14, and fixes the moving member 18 to the first slide table 11. Constitute. Similarly, in the other screw feed mechanism portion 16, the screw hole of the moving member 19 is fitted to the left screw portion 16b of the feed adjusting shaft portion 14, and the moving member 19 is fixed to the second slide table 12. And configure. A tension coil spring 22 is stretched between the first slide table 11 and the second slide table 12 to remove the backlash of the screw feed mechanism.

The tunnel unit 21 is attached to the first slide table 11 via the probe adjusting unit 20. The probe adjusting section 20 is composed of an adjusting screw section 23 and a tunnel unit base 24, which are respectively arranged at the three-minute positions on the first slide table 11. In the adjusting screw portion 23, the head portion of the screw rod portion 23a is formed into a disc-shaped operation head portion 23b. Further, a conical hole 23c is formed in the central portion of the operation head 23b, and the supporting sphere 25 is placed in this hole 23c.

The tunnel unit base 24 is provided with a support flange 24b at the upper end of a barrel 24a through which the tunnel unit 21 is inserted, and a locking flange 24c at the lower end of the barrel 24a. The tunnel unit base 24 is installed by inserting it into the mounting opening 11a formed in the first slide table 11 as shown in FIG. At this time, a conical hole 26 is formed in each of the corresponding positions of the adjusting screw portion 23 on the lower surface of the supporting flange 24b, and the supporting spheres 25 are placed in the holes 26, respectively. Place.

By doing so, the rotational expansion and contraction operation of each adjustment screw portion 23 can be smoothly and properly interlocked with the support flange 24b. In addition, a compression coil spring 27 is installed between the first slide table 11 and the locking flange 24c, and the tunnel unit base 24 is elastically pressed against the adjustment screw portion 23 to ensure the vertical position adjustment operation. Make something

The tunnel unit 21 attached to the tunnel unit base 24 has a piezoelectric element 21b installed below a thick shaft portion 21a having a flange at its upper end, and a lower end center thereof and a probe 28 projecting therefrom.

A mounting hole is provided in the second slide table 12, and an operating scope (microscope) 29 is installed in the mounting hole. An ITV camera 30 is installed above the operating scope 29.

Next, the usage and operation of the device of this example configured as described above will be described. First, as a preparation for measurement, the central target of the operating scope 29 and the relative position of the probe 28 are aligned. Therefore, in the state shown in FIG. 2, the central target of the operating scope 29 is aligned with the center of the scale plate 6 in the visual field. This work is performed by operating the adjusting knob 17 of the movement adjusting mechanism 13 to move the position of the operating scope 29 and moving and adjusting the guide support shaft 10 portion of the turntable 2.

Next, the turntable 2 is turned 180 degrees to move the scale plate 6 to directly below the probe 28. In this state, the three adjusting screw portions 23 are adjusted to move and adjust so that the tip of the probe 28 is aligned with the center of the scale plate 6, and the measurement preparation is completed.

Next, at the time of measurement, the device under test 7 is set on the sample table 5, and the operator operates the operation scope 29, and adjusts so that the position to be measured is located at the center of the monitor of the ITV camera 30. This adjustment is performed by the turning adjustment operation of the turntable 2 and the movement adjustment mechanism 13. When the adjusting knob 17 is rotated, the movement adjusting mechanism 13 is provided with a left screw and a right screw on the feed adjusting shaft portion 14, so that the first slide table 11 and the second slide table 12 are centered. It will be moved symmetrically.

Next, the turntable 2 is turned 180 degrees, and the DUT 7 is moved to a position right below the probe 28. At this time, the center of the monitor of the ITV camera 30 and the tip position of the probe 28 are rotationally symmetrical, so that the probe 28 is aligned and positioned at a required measurement point.

Next, the tunnel unit 21 is lowered to perform the measurement.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0026]

[Effect of device]

 As described in detail above, according to the fine positioning apparatus for the scanning tunneling microscope of the present invention, the DUT set on the sample table of the turntable is observed by the operating scope and measured by the tunnel unit. In the scanning tunneling microscope, the tunnel unit is mounted on the first slide table so that the position can be adjusted by three adjusting screw parts, and the operating scope is installed on the second slide table. The second slide table is equipped with a movement adjustment mechanism that allows the position to be adjusted symmetrically with respect to the center axis of the turntable by a right screw and left screw mechanism. Turn the turntable with the measurement point of the DUT aligned with the point When aligned directly under the Ruyunitto the probe is to be properly positioned in the measurement position. Therefore, there is an effect that the measurement point visually observed on the monitor can be easily and accurately measured by the tunnel unit.

Further, a scale plate is installed on the turntable, the target of the operating scope is aligned with the center of the scale, and then the turntable is turned to move the scale plate under the tunnel unit. Relative positioning of the operating scope and the probe can be performed simply by adjusting the three adjusting screws so that the tip of the probe is positioned, which has the effect of enabling quick and appropriate preparation for measurement. .

[Brief description of drawings]

FIG. 1 is a schematic plan view of a partial cross section of an essential part showing an embodiment of a fine positioning device for a scanning tunneling microscope of the present invention.

FIG. 2 is a schematic front view of a partial cross-section of a main part of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Microscope main body 2 ... Turntable 10 ... Guide support shaft 11 ... 1st slide table 12 ... 2nd slide table 13 ... Movement adjustment mechanism 14 ... Feed adjustment shaft part 16 ... Screw feed mechanism part 21 ... Tunnel unit 23 ... Adjustment screw Part 28 ... Probe 29 ... Operate scope 30 ... ITV camera

Claims (1)

[Scope of utility model registration request] 1. An object under test set on a sample table of a turntable is observed with an operating scope, and
In a scanning tunnel microscope configured to measure with a tunnel unit, the tunnel unit is attached to a first slide table so that the position can be adjusted with three adjusting screw portions, and the above operating scope is installed on a second slide table. The first slide table and the second slide table are configured by mounting a movement adjusting mechanism capable of position adjustment by a right-handed screw and a left-handed screw mechanism so as to be symmetrical with respect to the central axis of the turntable. Fine positioning device for scanning tunneling microscope.