JPH02284005A - Probe holding mechanism - Google Patents

Abstract

PURPOSE:To enable strong fixation and to facilitate the replacement of a probe by pressing the flank of the probe against an adjacent portion to the outside of the insertion opening of a fitting hole at right angles to a probe axis and giving moment around the insertion opening part as a fulcrum. CONSTITUTION:The tip part of the probe 1 is pressed upward by spring 5 and then the moment operates to press the rear end of the probe 1 against a point C at the lower side of the fitting hole 8 around a point (b) at the upper side of the insertion opening of a holding member 6 as the fulcrum. Consequently, even if the probe 1 is in a slightly curved shape, the probe is pressed at the two points (b) and (c) without fail to enable the strong fixation. Further, when the probe 1 is inserted into the fitting hole 8, the probe 1 can easily be inserted and held by slanting the probe 1 slightly to catch the rear end of the probe 1 by the entrance of the fitting hole 8 and then pressing the spring 5 away. Further, even if the spring 5 is rubbed against the probe 1 to wear away, only the spring 5 can easily be replaced with new one.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a probe constituting an electrode probe for detecting tunneling current and other electrical properties of a scanning tunneling microscope, and particularly relates to a probe that can be easily and reliably attached to a scanning tunneling microscope. This relates to a probe holding mechanism that is attached and held.

[Prior Art] In recent years, scanning tunneling microscopes having resolution on the order of atoms and molecules have been developed and are being applied to surface structure analysis, surface roughness measurement, and the like.

This scanning tunneling microscope utilizes the fact that a voltage is applied between a conductive sample and a conductive probe, and when the probe is brought close to a distance of about 1 nm, a tunnel current flows, and the tunnel current changes exponentially with the distance. This is what I did. As a probe, the tip of which has been polished to a very sharp point by electropolishing etc. is used to scan two-dimensionally while keeping a constant distance from the sample surface made of a conductive material. The tunnel current changes, and a surface image can be obtained (rSolid State Physics J Vo122, No. 3
1987 PP176-186).

In such devices, the probe is held firmly in a drive mechanism,
In addition, a probe holding mechanism that can be easily replaced is required. The conventional probe holding mechanism uses a spring 4 as shown in FIG.
A mechanism was used to hold down the probe 1 in
(See Publication No. 236992). 2 points the tip of probe 1 to x, y
, a cylindrical piezoelectric element operated in the z direction, a common electrode is provided on its inner circumferential surface, and M and Rfi divided as shown in the figure are provided on the outer circumferential surface so as to drive in each direction. There is. For example, when a voltage is applied to the Z electrode and the common electrode, the cylinder expands and contracts in the Z direction. Furthermore, when a voltage of opposite polarity is applied to the y electrodes provided facing each other, one expands and the other contracts, a bending force acts on the cylinder, and the tip of the probe 1 moves in the y direction. A holding member 3 having a hole into which the probe 1 fits is fixed to the cylindrical piezoelectric element 2 . Half of this holding member 3 is a notch, and has a mechanism for pressing and holding the probe 1 with a spring 4.

[Problem A to be Solved by the Invention] However, in the above conventional example, since the probe 1 is pressed against the notch of the holding member 3 by the spring 4 as shown in the cross-sectional view of FIG. If it is badly bent,
The probe 1 touches the holding member 3 only at the part pressed by the spring 4.
However, the rear end of the probe 1 is not fixed, which has the drawback that firm fixation is impossible. Furthermore, when replacing the probe 1, the spring 4 must be sprung up before the probe 1 is inserted into the fitting hole, which requires time and effort.

[Means and effects for solving the problem] The present invention is characterized in that the probe is pressed from the side near the outside of the entrance of the fitting hole that holds the probe at right angles to the probe axis, and the artificial part of the fitting hole is used as a fulcrum. By providing an elastic member that provides a moment, the probe can be firmly fixed and held, and the probe can be easily replaced.

[Example] The present invention will be described in detail below using the drawings.

FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a sectional view illustrating its operation.

In FIG. 1, numeral 1 is a probe made of tungsten or pt whose tip has been sharpened by electrolytic polishing or mechanical polishing, and 2 is a cylindrical piezoelectric element that drives the probe 1 in the x, y, and z directions. A holding member 6 is fixed to the cylindrical piezoelectric element 2 by adhesive or the like, and a fitting hole 8 (Fig. 2) with a diameter that allows the probe 1 to be smoothly inserted is provided in the center of the holding member 6. .

Further, a rod-shaped spring 5 is provided near the outside of the insertion opening of the probe so as to be perpendicular to the probe 1 so as to press the probe 1 from the side.

Both ends of the spring 5 are detachably supported by an annular protrusion 6a provided around the probe tip of the holding member 6.

Next, the present invention will be explained in detail using FIG.

FIG. 2(A) is a cross-sectional view of the state in which the probe 1 is held.

The tip of the probe 1 is pressed upward by the spring 5, and a moment acts on it, with the point above the insertion opening of the holding member 6 serving as a fulcrum, and the rear end of the probe 1 is placed below the fitting hole 8. is pressed to point C.

Therefore, even if the shape of the probe 1 is somewhat beveled, it will always be held down at two points, point and point C, and firm fixation will be possible.

Furthermore, as shown in FIG. 2(B), when inserting the probe 1 into the fitting hole 8, the probe 1 is slightly tilted, and the rear end of the probe 1 is hooked into the entrance of the fitting hole 8. It can be easily inserted and held by pushing away the spring 5.

Furthermore, even if the spring 5 is worn out by the probe 1, only the spring 5 can be easily replaced with a new one.

Next, another embodiment will be explained using FIG. 3. In this embodiment, instead of the elastic spring that presses the probe in the previous embodiment, rubber or flexible resin is used to create an eccentric spring through which the probe passes, as shown in the front view of FIG. 3(B). Elastic member 7 with holes
is fixed to the holding member 6. As shown in FIG. 3(A), the side surface of the probe 1 is pressed upward by an elastic member. The insertion opening of the fitting hole for the probe is machined into a tapered shape so that the probe can be easily inserted. According to such a configuration, effects similar to those of the embodiment described above can be obtained.

In the embodiment described above, the case where the probe is held by a cylindrical piezoelectric element has been described, but the driving element of the probe may be of other shapes, such as a tri-bod type piezoelectric element.

[Effects of the Invention] As explained above, in order to hold the probe, the side surface of the probe is pressed near the outside of the insertion opening of the fitting hole in a direction perpendicular to the probe axis, and the insertion opening is used as a fulcrum. By arranging the elastic member to provide a moment, firm fixation is possible and the probe can be easily replaced.

[Brief explanation of drawings]

Figure 1 is a perspective view of an embodiment of the present invention, Figures 2 (A) and (B)
3(A) and (B) are cross-sectional views showing different probe attachment states for explaining the action of the probe holding mechanism according to the present invention.
) are a sectional view and a front view of another embodiment of the present invention, FIG. 4 is a perspective view of a conventional probe holding mechanism, and FIG. 5 is a sectional view of a conventional probe holding mechanism. DESCRIPTION OF SYMBOLS 1... Probe, 2... Cylindrical piezoelectric element, 5... Spring, 6... Holding member, 7... Elastic member, 8... Fitting hole.

Claims (4)

[Claims] (1) It has a fitting hole into which the probe is inserted and held, and an elastic member is provided near the outside of the insertion opening of the fitting hole to press the side surface of the probe in a direction perpendicular to the probe axis. A probe holding mechanism. (2) The probe holding mechanism according to claim 1, wherein the elastic member is a linear spring that crosses a part of the insertion opening. (3) The probe holding mechanism according to claim 1, wherein the elastic member is made of an elastic material having an opening eccentric to the insertion port. (4) The probe holding mechanism according to claim 1, wherein the probe is a probe for detecting tunneling current of a scanning tunneling microscope.