JP5306015B2 - Scanning probe microscope probe and scanning probe microscope - Google Patents

Description

  The present invention relates to a probe used in a scanning probe microscope (SPM), and more particularly to a probe suitably used in a so-called scanning multi-probe microscope (MPSPM) having a plurality of probes.

  Conventionally, as a probe used in a scanning probe microscope, as shown in Patent Document 1 or Patent Document 2, a probe using a tuning fork (tuning fork type vibrator) has been considered. Probes using these tuning forks are provided with a probe part parallel or perpendicular to the arm part of the tuning fork so that the tip of the probe part is substantially perpendicular to the sample surface during sample scanning. Has been.

  However, when such a probe is used in a scanning multi-probe microscope (MPSPM), when approaching the tip of the probe unit, a part other than the tip of the probe part or a probe part such as a tuning fork is used. There is a problem that the tip of the probe portion cannot be brought close to, for example, several nanometers or less due to contact of the movable member.

Japanese Patent Application Laid-Open No. 2004-239679 JP 2007-120975 A

  Therefore, the present invention has been made to solve the above-mentioned problems all at once, and its main intended task is to bring the tip of the probe portion as close as possible when a plurality of probes are used. It is.

That is, the probe for a scanning probe microscope according to the present invention includes a tuning fork vibrator, a support body that supports the tuning fork vibrator, and the entire side surface of one arm portion of the tuning fork vibrator is fixed. A probe portion fixed to the side surface of the other arm portion of the tuning fork vibrator and having a sharpened tip, and the probe portion is in the extending direction of the other arm portion. The tip of the probe part is fixed to the outside of the tuning fork vibrator, and the tip of the probe part is provided in front of the tip of the two arm parts.

  In such a case, the tip of the probe unit is positioned outside the other part, so that when using a plurality of probes, the tip of the probe unit can be brought as close as possible. it can.

  In order to simplify the configuration of the probe unit and make it easier to bring the tip of the probe unit closer, it is desirable that the probe unit has a substantially linear shape.

Furthermore, a scanning probe microscope according to the present invention is provided so as to face a sample stage on which a sample is placed and the sample placed on the sample stage, and one of the tuning fork vibrator and the tuning fork vibrator with entire side of the arm portions is fixed, support for supporting the tuning-fork vibrator, and is fixed to the side surface of the other arm portion of the tuning-fork oscillator, the probe tip is sharpened A plurality of probes having a portion, and a physical quantity measuring unit that measures a physical quantity acting between the sample and the probe portion, and in at least one of the plurality of probes, the probe portion is the other probe The tip of the probe part is fixed to the outside of the tuning fork vibrator with respect to the extending direction of the arm part, and the tip of the probe part is provided in front of the tip of the two arm parts. .

  According to the present invention configured as described above, the tip of the probe portion can be made as close as possible when a plurality of probes are used.

1 is an overall configuration diagram of a scanning probe microscope according to a first embodiment of the present invention. It is a side view which shows typically the structure of the probe of the embodiment. It is a top view which shows the state which made the probe part front-end | tip of four probes approached. It is the perspective view seen from the downward direction of the probe of the embodiment. It is a side view of the probe of the embodiment. It is a bottom view of the probe which concerns on 2nd Embodiment.

<First Embodiment>
Hereinafter, a first embodiment of a scanning probe microscope (SPM) according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the scanning probe microscope 100 according to the present embodiment includes a sample stage 2 on which a sample S is placed and movable in the XY directions, and a sample S placed on the sample stage 2. A plurality of probes 3 (see FIG. 2) that are provided opposite to each other and have a transducer 33 and a probe portion 34 fixed to the transducer 33; a stage moving mechanism 4 that moves the sample stage 2 in the XY direction; A probe moving mechanism 5 provided for each probe 3 and moving the probe 3 in the XY direction parallel to the surface of the sample S and the Z direction perpendicular to the surface of the sample S, and the transducer 33 of the probe 3 at its natural frequency (resonance frequency). An AC power source (not shown) that resonates, a shift amount detection unit (physical quantity detection unit) 6 that converts a shift amount of the vibration amplitude or vibration frequency of the vibrator 33 into a voltage and outputs the voltage, and each of the moving mechanisms 4 and 5 When you control The information processing apparatus 7 that generates a surface image of the sample S accepts a voltage signal from the monitor-shift-amount detector 6, and a.

First, a configuration other than the probe 3 will be briefly described.
The stage moving mechanism 4 and the probe moving mechanism 5 are configured using a piezo fine movement element, and move the sample stage 2 and each probe 3 by controlling the voltage value applied by the information processing device 7.

  The shift amount detection unit 6 detects the vibration amplitude of the transducer 33 or the physical quantity generated by the interaction between the surface of the sample S and each probe unit 34 when the probe unit 34 or the sample stage 2 is moved in the XY direction. It detects the shift amount of the vibration frequency.

  The information processing device 77 is a general purpose or dedicated device including a CPU, memory, input / output channels, input means such as a keyboard, a display, and the like. The input / output channels include an A / D converter, a D / A converter, and an amplifier ( An analog-digital conversion circuit such as (not shown) is connected.

  The CPU and its peripheral devices cooperate with each other according to a program stored in a predetermined area of the memory, so that the information processing apparatus 7 controls the stage moving mechanism 4 and the probe moving mechanism 5 and the like. Generate an image.

Next, the probe 3 will be described.
As shown in FIG. 2, the probe 3 includes an attachment column 31 attached to the probe moving mechanism 5, a support body 32 provided at the tip of the attachment column 31, and a vibrator 33 fixed to the support body 32. And a probe portion 34 fixed to the transducer 33.

  The attachment column 31 is attached to the probe moving mechanism 5 so as to be inclined with respect to the surface of the sample S. Accordingly, the probes 3 are brought closer to each other while the probe moving mechanisms 5 are separated as much as possible. That is, the probe moving mechanisms 5 are prevented from contacting each other when the probes 3 are brought close to each other.

  The support 32 is preferably a conductor or semiconductor having a sufficient insulating film, and is made of, for example, a plate-like member having a substantially rectangular shape. And the attachment support | pillar 31 is extended diagonally upward from the upper surface 32a back side of the support body 32. As shown in FIG. Thereby, in the state which attached the probe 3 to the probe moving mechanism 5, the lower surface 32b of the support body 32 is provided so that it may become substantially parallel with respect to the sample surface.

  The vibrator 33 is a tuning fork (tuning fork vibrator) formed of a crystal vibrator, and the outer surface of one arm portion 331 is fixed to the lower surface 32b of the support body 32 along the longitudinal direction by an adhesive or the like. The That is, the vibrator 33 is fixed to the lower surface 32b of the support plate 32 so as to be substantially parallel to the sample surface so that one arm portion 331 of the vibrator 33 is located above and the other arm portion 332 is located below. Note that the wiring 35 from the electrode provided on the vibrator 33 is taken out to the outside through a conductive adhesive 36 such as a silver paste manually applied to the side surface of the support 32.

  The probe portion 34 has a substantially linear shape formed of tungsten (W), platinum iridium (Pt—Ir), or the like, and is fixed to the lower surface or side surface of the other arm portion 332 of the vibrator 33. . The length is 2 mm or more, preferably 2 to 5 mm, for example. Further, the tip 34A of the probe 34 is sharpened by chemical etching and mechanical polishing. More specifically, the probe portion 34 has a shape that gradually decreases in diameter as it goes to the tip, and its cross-sectional center line 34C has a substantially straight line.

  Thus, in the state where all the probes 3 of the present embodiment are arranged facing the sample S, the tip 34A of the probe portion 34 is provided to be inclined with respect to the sample surface, and the transducer 33 and It is provided on the outer side in the surface direction of the sample surface relative to the support 32, and is visible from above substantially perpendicular to the sample surface.

  That is, the probe section 34 is on the lower surface of the other arm section 332 (extending substantially parallel to the sample surface) of the vibrator 33, and the vibrator 33 with respect to the extending direction of the arm section 332. Inclined outward (specifically, inclined outward 30 degrees) and fixed. At this time, the cross-sectional center line 34C of the probe portion 34 is provided so as to be inclined by 60 degrees with respect to the normal direction of the sample surface. The inclination angle is not limited to these.

  Further, the tip 34A of the probe portion 34 is positioned outside the vertical projection range with respect to the sample surface of the transducer 33 and the support 32. Specifically, the tip 34A of the probe portion 34 is provided in front of the tips of the transducer 33 and the support 32, and is configured to be visible from above or below substantially perpendicular to the sample surface. That is, the upper part or the lower part of the tip 34A of the probe part 34 is configured such that no part other than the tip of the probe part 34 and other movable members are present. More specifically, the tip 34 </ b> A of the probe portion 34 is configured to be located outside the circumscribed circle of the transducer 33 and the support body 32.

  With such a configuration, when two or more probes 3 are brought close to each other, other members are prevented from coming into contact before the tip 34A of the probe portion 34 comes into contact. As shown in FIG. 3, the four probes 3 of the present embodiment are provided such that adjacent probes are rotated by 90 degrees, but the tips 34A of the probe portions 34 of the four probes 3 are brought into contact with each other. Even if it does, parts other than tip 34A of probe part 34 do not contact.

  According to the scanning probe microscope 100 according to the present embodiment configured as described above, in the case where a plurality of probes 3 are used, the probe is not in contact with a portion other than the tip 34A of the probe portion 34 or other members. Since the tips 34A of the portion 34 can be brought into contact with each other, the tip 34A of the probe portion 34 can be brought as close as possible.

Second Embodiment
Next, a second embodiment of the scanning probe microscope according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the member corresponding to the said embodiment.

  The scanning probe microscope 100 of the present embodiment is different from the first embodiment in the basic configuration of the probe 3. That is, the basic configuration of the probe 3 of the above embodiment has a problem that the adhesion of the vibrator 33 is likely to be unstable, and stable supply is difficult. As a result, it is difficult to obtain stable resonance in the vibrator 33. Further, since the silver paste 36 is manually applied when the wiring 35 is performed, there is a problem that the processing accuracy varies, and the adjustment of the viscosity and the like of the silver paste 36 is complicated.

  The probe 3 of this embodiment is made to solve such a problem, and as shown in FIGS. 4 and 5, two lead pins 37 are provided so as to penetrate from the upper surface 32a to the lower surface 32b. A support body 32, a transducer 33 fixed to the side surface 32 c of the support body 32, and a probe portion 34 fixed to the transducer 33. The configuration and specific arrangement of the probe unit 34 are the same as in the above embodiment.

  The support 32 is made of, for example, kovar (an alloy in which nickel and cobalt are mixed in iron), stainless steel, or the like, and has a substantially equal cross-sectional shape along the vertical direction. 4 and 6, the support body 32 has a cross-sectional shape in which both end portions in the longitudinal direction form a semicircular shape. However, the support body 32 is not limited thereto, and may have a rectangular shape, for example. In addition, one of the side surfaces 32c along the longitudinal direction serves as a fixed plane on which the vibrator 33 is fixed.

  Further, the support body 32 is formed with a through hole 32h into which the two lead pins 37 are inserted along the vertical direction. In FIG. 5 and the like, the through-hole 32h is provided along the longitudinal direction, but is not limited thereto. The lead pin 37 inserted into the through hole 32h is fixed by glass sealing. The lead pin 37 fixed to the support body 32 in this way is also used as an attachment column for attaching the support body 32 to the probe moving mechanism 5. The lead pin 37 is curved on the upper surface side of the support 32 in the direction opposite to the direction in which the probe portion 34 is provided. This prevents the probe moving mechanisms 5 from interfering with each other even if the tips 34A of the plurality of probe parts 34 are brought into contact with each other. In addition, it is good also as a structure which provides an attachment support | pillar separately similarly to the said embodiment, without using the lead pin 37 as an attachment support | pillar.

  The vibrator 33 is a tuning fork (tuning fork vibrator) as in the above embodiment, and one arm portion 331 is fixed to the side surface 32c of the support 32 with, for example, an epoxy adhesive. Specifically, the vibrator 33 is fixed so that one or the other arm portion 331, 332 is along the planar direction of the support lower surface 32b, and the entire side surface of the one arm portion 331 is attached to the side surface 32c by an adhesive. Fixed. In a state where the one arm portion 331 is fixed, the vibrator 33 is provided along the side surface 32c, and the other arm portion 332 is provided to extend outward from the lower surface 32b of the support body 32. become.

  In the probe 3 configured as described above, wiring between the electrode provided on the vibrator 33 and the lead pin 37 is performed by a wire bonding apparatus. That is, the probe 3 that is not wired is arranged in the wire bonding apparatus so that the side surface on which the electrode of the vibrator 33 is formed faces the capillary that feeds out the wire. At this time, the lead pins 37 are arranged so as to extend substantially in the horizontal direction. As a result, the electrode provided on the vibrator 33 and the upper end side surface of the lead pin 37 are electrically connected by the Au wire 35.

  According to the scanning probe microscope 100 according to the present embodiment configured as described above, the entire side surface of one arm portion 331 is fixed to the side surface 32c of the support body 32 as compared with the probe 3 of the embodiment. In addition, the adhesion of the vibrator 33 can be stabilized, and a stable supply becomes possible. Therefore, stable resonance can be obtained in the transducer 33 of the probe 3. In addition, wiring to the outside can be performed using the lead pin 37 and wiring of the gold wire 35 between the lead pin 37 and the vibrator 33 can be performed using a wire bonding apparatus. In this case, wiring can be performed automatically, and variations in processing accuracy can be suppressed.

The present invention is not limited to the above embodiment.
For example, in the above-described embodiment, in all of the plurality of probes, the tip of the probe portion is provided to be inclined with respect to the sample surface, and is provided on the outer side in the surface direction of the sample surface relative to the vibrator and the support. Although visible from above substantially perpendicular to the surface, if at least one probe has the above-described configuration, there is an effect that the tips of the probe portions can be brought closer to each other as compared with the conventional case.

  Further, as the shape of the probe portion, in addition to a substantially linear shape, it may be bent or curved. At this time, the center line of the cross section at the tip of the probe portion may be configured to be inclined with respect to the normal direction of the sample surface.

  Further, as the vibrator of the embodiment, a piezoelectric element may be used in addition to the tuning fork vibrator.

  Further, the mounting column and the support may be formed as a single body, and may be a conductor or semiconductor having a sufficient insulating film (body) in part.

  In addition, the scanning probe microscope (SPM) includes a tunneling current scanning tunneling current microscope (STM), an atomic force microscope (AFM) for detecting atomic force, a scanning Kelvin force microscope (KFM), a near field Near-field optical microscope (NSOM) for detecting light, magnetic force microscope (MFM) for detecting magnetic force, friction force microscope (FFM) for detecting frictional force, scanning near-field ultrasonic microscope (SSAM) for detecting ultrasonic waves A scanning ion microscope (SICM) that detects ion conduction may be used.

  In addition, in the above-described embodiment, the number of probes is four, but may be two or three, or may be five or more.

  Furthermore, the probe unit of the above embodiment may be configured by an optical fiber and configured as a Raman spectroscopic analyzer.

  In addition, when light is applied to the tip of the probe unit in the above embodiment to obtain the effect of Raman light reinforcement at the tip of the probe unit, the one protruding forward rather than being provided substantially perpendicular to the sample surface However, the configuration can be simplified when considering the optical path. When used in this way, even a single probe is effective.

  In addition, in the above-described embodiment, the vibrators are provided such that their arm portions are positioned up and down, but may be provided so as to be positioned left and right. Further, the arm portion may be extended to the sample surface side. Further, the arm portion may be extended to be inclined with respect to the sample surface.

  In the above embodiment, the sample surface is arranged vertically upward, and the probe is provided vertically above the sample surface. In addition, the sample surface is arranged vertically downward, and the probe May be provided vertically below the sample surface.

  In addition, some or all of the above-described embodiments and modified embodiments may be combined as appropriate, and the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. .

DESCRIPTION OF SYMBOLS 100 ... Scanning probe microscope S ... Sample 2 ... Sample stage 3 ... Probe 33 ... Probe 34 ... Probe part 34A ... Tip 6 ... Physical quantity measuring part ( Shift amount detector)

Claims (3)

Tuning fork type vibrator,
The entire side surface of one arm portion of the tuning fork vibrator is fixed, and a support that supports the tuning fork vibrator;
The probe fork is fixed to the side surface of the other arm of the tuning fork vibrator, and has a probe with a sharpened tip.
The probe section is fixed to the outside of the tuning fork vibrator with respect to the extending direction of the other arm section, and the tip of the probe section is in front of the tips of the two arm sections. A probe for a scanning probe microscope provided.   The probe for a scanning probe microscope according to claim 1, wherein the probe portion has a substantially linear shape. A sample stage on which the sample is placed;
A support that is provided to face the sample placed on the sample stage, supports the tuning fork vibrator, and the entire side surface of one arm of the tuning fork vibrator, and supports the tuning fork vibrator. And a plurality of probes that are fixed to the side surface of the other arm portion of the tuning fork vibrator and have a probe portion with a sharpened tip,
A physical quantity measuring unit for measuring a physical quantity acting between the sample and the probe part,
In at least one of the plurality of probes, the probe portion is fixed to the outside of the tuning fork vibrator with respect to the extending direction of the other arm portion, and the tip of the probe portion is A scanning probe microscope provided in front of the tips of two arm portions.