JPH04162229A - Probing device - Google Patents

Abstract

PURPOSE:To adjust the position of a probe finely with the large quantity of displacement not only in the direction approaching to the surface of a body but also in at least the biaxial direction in the direction vertical to the direction by finely adjusting the position of the probe through a fine link mechanism. CONSTITUTION:A probe device has a probe 1 and a fine moving means finely moving the probe 1 and finely adjusting a position, and the fine moving means has a link mechanism connected to the probe 1. For example, a pantograph type micro-probe 1 is composed of four shafts 2, four joints 3 consisting of hinge structure, a support point 5, and a probe 4 for generating tunnel currents formed onto the joint oppositely facing a joint as the support point 5, driving beams 6 are brought into contact with the two shafts 2 directly coupled with the support point 5, the driving beams 6 are displaced in the longitudinal directions by applying voltage to a linear actuator, and the position of the probe 4 is displaced to an arbitrary position within a considerably wide range parallel with a substrate surface. Accordingly, the probe 1 can be moved finely by the quantity of displacement in the same extent not only in one direction but also in the direction vertical to the direction.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is applicable to a memory system that records and reproduces information using tunnel current, etc., and a microscope (STM) and spectroscope (STM) that uses tunnel current, etc. This invention relates to a probe device used in STS) and the like.

[Conventional technology] Conventionally, ultra-small tunnel current generating microprobes have been fabricated on semiconductor substrates such as Si using semiconductor processing technology for the purpose of surface observation or simultaneous recording/reproduction at multiple locations at high density. There have been several reports of simultaneous production of multiple units. The microprobes in both reports are based on a cantilevered beam structure, and the displacement of the probe is minutely controlled by applying piezoelectric or electrostatic force to the cantilevered beam to cause elastic deformation. There is. For example, rTran
sducers' 90. In "Lecture number D36", S.
1000 μm long, 200 μm wide, 8 μm thick on the i-substrate
A bimorph structure cantilever made of piezoelectric material ZnO is formed with a thickness of 16 μm in the direction perpendicular to the cantilever and 0.0 μm in the short direction of the cantilever. Displacement is obtained by piezoelectric bending deformation of 5 μm and piezoelectric expansion/contraction deformation of 0.01 μm in the longitudinal direction of the cantilever beam, realizing displacement control in biaxial directions.

The displacement control mechanism of the microprobe is required to simultaneously scan a wide area at high speed and high density while simultaneously controlling the displacement in two directions parallel to the medium surface. It is also required to have the ability to perform Therefore, as a displacement control mechanism of the microprobe,
Ideally, a control mechanism that can make large displacements at high speeds in each of the three axial directions is desirable.

[Problem to be solved by the invention] However, in the displacement control using a cantilever beam as seen in the conventional example described above, due to its structure, the main displacement is limited to bending displacement in the direction perpendicular to the cantilever surface. There are drawbacks. Although the piezoelectric bimorph type cantilever beam described above allows displacement in three axes, the amount of displacement in the direction of the axis perpendicular to the cantilever surface, which is the main displacement, is The amount of displacement in the short direction in parallel planes is only a few percent, the amount of displacement in the long direction is only 0.1% or less, and the displacement in two directions other than the main displacement direction is minute. . The amount of displacement during bending deformation is inversely proportional to the thickness of the structure in the bending direction, so in the case of a cantilever beam structure, the ratio of principal displacement to short direction displacement is naturally limited structurally by the ratio of beam thickness to width. . On the other hand, the form of displacement in the longitudinal direction is based on stretching deformation, which in principle has a much smaller amount of deformation than bending deformation. With a probe having a cantilever structure, it is considered difficult to significantly improve the amount of displacement in two axes other than the main displacement direction axis.

In view of the problems of the prior art, an object of the present invention is to
The object of the present invention is to significantly improve the amount of displacement in two axes other than the main displacement direction axis in a microprobe device.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides a probe for recording information on the surface of an object and/or detecting information on the surface of an object, and a probe for slightly moving the probe to detect the position of the probe. In a probe device equipped with a fine movement means for finely adjusting the
The fine movement means is characterized in that it includes a link mechanism connected to the probe, and finely moves the probe via this link mechanism.

As the link mechanism, for example, a constrained rotation chain constituted by a plurality of shaft parts and a plurality of joint parts, such as one having a pantograph structure, can be used.

The fine movement means includes, for example, a suspension mechanism capable of displacing a movable part that is connected to and suspended from a fixed part via an elastically deformable part by, for example, an electrostatic force acting between opposing comb-tooth electrodes. , the probe is moved slightly by transmitting the displacement of this movable part to the link mechanism.

The probe is for recording information on the surface of an object and/or detecting information on the surface of the object, for example, by means of a tunneling current flowing between the object and the probe.

Preferably, the probe and the fine movement means are formed by etching on the same substrate, in which case the fine movement means finely moves the probe within a plane parallel to the substrate surface.

Furthermore, the substrate portion where the probe and fine movement means are formed is
It is formed by being separated from other substrate parts by etching except for a predetermined part, and this predetermined part is structured so that it can swing in a direction perpendicular to the substrate surface of the other board part by elastic deformation. The device may further include means for finely moving the substrate portion on which the probe and the fine movement means are formed along the swinging direction.

On the other hand, in another aspect of the present invention, there is provided a cantilever type actuator that drives the probe by deforming a beam holding the probe, a portion that can be elastically deformed with respect to a fixed portion, and the actuator that is elastically deformable. a drive part connected to the movable part for linearly moving the actuator.

[Operation] In this configuration, when recording information on the object surface and/or detecting information on the object surface, it is necessary to finely adjust the position of the probe by moving the probe. , the probe position is finely adjusted by moving the probe slightly via a link mechanism connected to the probe, so the positive and diverse movement transmission function of the link mechanism allows the probe to move not only in one direction, but also in one direction. It can also be slightly moved in a direction perpendicular to this with the same amount of displacement.

For example, when multiple probe devices are formed on a substrate including a semiconductor layer using semiconductor processing technology, a link mechanism as a new mechanism and a suspension mechanism that acts as an actuator for the new mechanism are simultaneously formed on the same substrate. By doing this, large displacement control of the probe position of several μm to several μm can be achieved in at least two of the three mutually perpendicular axes directions.

A link mechanism is a constraint rotation chain composed of a plurality of axes and a plurality of joints connecting the axes, and the displacement of the -axis is transmitted to the other axes via the joints. A pantograph structure is a typical link mechanism. If a pantograph structure is formed on the board surface parallel to the board surface, with only the joint points fixed on the board, the joint points opposite to the fixed joints will be parallel to the board, which is a problem with cantilever structures. It has two degrees of freedom for displacement in the plane, and by driving any two wooden shafts by some means, it is possible to displace the probe to any point within the range limited by the shaft length. Ru.

A suspension mechanism is, for example, a mechanism in which a structure as a movable part is suspended by a beam made up of multiple girders connected to a support point (a movable part). Large displacements in one axis direction can be performed. This suspension mechanism has been studied for application as a linear actuator by providing an electrostatic drive mechanism using the above-mentioned comb tooth-shaped electrode structure, and it has been reported that a linear displacement of 10 μm was obtained with a beam length of 200 μm. (IEEE Micro Electro
Mechanical Systems '89.2
pp53-59) 6 On the other hand, in an embodiment in which a cantilever-type actuator is combined with an elastically deformable part and a driving part, displacement in the longitudinal direction, which is a problem with the cantilever-type actuator, is caused by elastic deformation. Since this is performed by the deformable portion and the driving portion, a large amount of displacement in at least two axial directions can be obtained as well.

[Example code] Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a schematic diagram of a microprobe device (pantograph type probe unit) using a pantograph structure according to a first embodiment of the present invention. This device consists of 51 substrates, 7
A pantograph-type microprobe 1 and a suspended-type linear actuator (shown in Fig. 3) were obtained by processing the polycrystalline St deposited thereon using micromechanics techniques such as selective etching, anisotropic etching, and sacrificial layer etching. ) is provided with a drive beam 6 directly connected to the drive beam 6. This linear actuator and drive beam 6 are also formed at the same time as the microprobe 1 using polycrystalline Si deposited on the Si substrate 7. The pantograph type microprobe 1 has four shafts 2, four joints 3 having a hinge structure,
It is composed of a support point 5 and a tunnel current generating probe 4 formed on the joint opposite to the joint serving as the support point 5. Although not clearly shown in the figure, the tunnel current detected by the probe 4 is transmitted by a lead electrode formed on the shaft 2 to a current amplification circuit provided on the Si substrate 7, a current voltage It is guided to a conversion circuit, etc.

FIG. 3 is a schematic diagram of the suspension type linear actuator. A plurality of girders 3 connected to two pairs of left and right support parts 34
The structure is such that a beam 6 at the center is suspended by two pairs of left and right beams 32 consisting of beams 32.
Due to the elastic deformation of , it can be displaced only in a direction parallel to the substrate and perpendicular to the plurality of girders 33 . As the driving force, electrostatic force generated in the comb tooth-shaped electrode portion 31 is used. The movable portion of the comb-tooth electrode 31 directly connected to the beam 6 generates a driving force by being pulled in or pushed out between the opposing comb-tooth electrodes 31.

Next, the operating principle of this microprobe device will be explained.

In a steady state (no driving force applied) as shown in FIG. 1, the driving beam 6 is in contact with the two-piece shaft 2 directly connected to the support point 5, but no force is applied thereto.

By applying a voltage to the comb-shaped electrode portion 31 of the linear actuator, the drive beam 6 directly connected to the linear actuator is displaced back and forth. As shown in Figure 1J2, the left and right drive beams 6 are both in contact with the shaft 2 directly connected to the support point 5, which is different from the steady state in which forces are exerted on each other between the drive beams 6 and the shaft 2. By arbitrarily setting the inclination angle of the axis 2 within a range that maintains a balanced state, the position of the probe 4 provided on the joint 3 facing the support point 5 can be moved forward from the position in the steady state. can be displaced to any position within a fairly wide range parallel to the plane formed by the pantograph, that is, the substrate plane.

For example, when the length of each axis 2 is 100 μm, it is possible to displace the substrate by several μm to several μm in two axial directions parallel to the substrate.

FIG. 4 shows a microprobe device according to a second embodiment of the invention. This device applies the driving force from a suspended linear actuator 48 similar to that shown in FIG. The signal is transmitted to a microprobe 41 having a modified pantograph structure. The inclination angle of the shaft 2 directly connected to the support point 45 is independently controlled through a rack and pinion mechanism formed by a rack 47 formed at the tip of the beam of the suspended linear actuator 48 and a pinion gear 46 formed at the support point 45. It is designed to be controlled.

FIG. 5 shows a microprobe device (a hybrid probe unit formed on a seesaw mechanism) according to a third embodiment of the present invention. This device combines the microprobe device shown in FIG. 1 with a seesaw mechanism that enables displacement in a direction perpendicular to the substrate 7 by torsional rotation around two supporting shafts 53. Under the substrate 7 on which the device shown in FIG.
There is a gap formed by anisotropic etching, and a rotational moment around the support shaft 53 is generated by electrostatic force between electrode surfaces facing each other, which are formed on opposing surfaces across the gap. Accordingly, the microprobe 1 can be swung around the support shaft 530. According to this, a drive mechanism that controls the probe position with a large displacement of several μm to several μm in any three axial directions is realized. In addition, a similar three-dimensional drive mechanism can be realized by combining a pantograph type mechanism and a piezoelectric bimorph cantilever structure. FIG. 6 is a schematic diagram of a fourth embodiment in which a suspension mechanism (suspension type linear actuator) 62 and a piezoelectric bimorph cantilever 61 are combined. Displacement in the longitudinal direction parallel to the substrate, which is particularly difficult for the cantilever type, is compensated for by displacement in the uniaxial direction parallel to the substrate by the suspension mechanism 62. This is realized by forming a piezoelectric bimorph cantilever 61 at one end of a beam 69 held at the center of a suspension mechanism 62 that includes a driving force generating section 67 .

The suspension mechanism 62 is stably held by four support points 68.

[Effects of the invention] As explained above, the probe position can be finely adjusted through the fine link mechanism! 3 adjustment, or by combining a cantilever type actuator, an elastically deformable part, and a driving part, the probe position can be adjusted not only in the direction close to the object surface but also in the direction perpendicular to it, at least Fine a adjustment can be made with a large amount of displacement in two axial directions.

Therefore, it is possible to scan a wider area of the object surface with the probe at high speed and with high density.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a pantograph type probe unit according to a first embodiment of the present invention, FIG. 2 is an explanatory diagram showing the operating state of the device in FIG. 1, and FIG. 3 is a diagram showing the operating state of the device in FIG. A schematic diagram of a suspended linear actuator used in the device; FIG. 4 is a schematic diagram of a pantograph probe unit using a rack and pinion mechanism according to a second embodiment of the present invention; FIG. A schematic diagram of a hybrid probe unit formed on a seesaw mechanism according to a third embodiment, and FIG. 6 shows a suspension mechanism built into a piezoelectric bimorph cantilever according to a fourth embodiment of the present invention. FIG. 2 is a schematic diagram of a hybrid probe unit. 7: Substrate, 1, 4.1: Microprobe, 6: Drive beam, 2 axes, 3: Joint, 4: Probe, 5, 34: Support part, 32: Beam, 31: <L tooth-shaped electrode , 48.62: Suspension linear actuator (suspension mechanism), 45: Support point, 47: Rack, 46: Binion gear, 53: Support shaft, 5
4: Etching window, 61: Piezoelectric bimorph cantilever, 6
9: Beam, 68: Support point. Patent applicant Canon Co., Ltd.

Claims (9)

[Claims] (1) In a probe device comprising a probe for recording information on an object surface and/or detecting information on the object surface, and a fine movement means for finely adjusting the position of the probe by finely moving the probe, the fine movement means A probe device comprising a link mechanism connected to the probe, and the probe is slightly moved via the link mechanism. (2) The probe device according to claim 1, wherein the link mechanism is a constrained rotation chain constituted by a plurality of shaft parts and a plurality of joint parts. (3) The probe device according to claim 2, wherein the constrained rotation chain has a pantograph structure. (4) The fine movement means includes a suspension mechanism capable of displacing a movable part that is connected to the fixed part via an elastically deformable part, and transmits the displacement of the movable part to the link mechanism to move the probe. 2. The probe device according to claim 1, wherein the probe device moves slightly. (5) The probe device according to claim 1, wherein the suspension mechanism includes an actuator that displaces the movable portion with respect to the fixed portion by electrostatic force acting between opposing comb-tooth electrodes. . (6) The probe is for recording information on the object surface and/or detecting information on the object surface by means of a tunnel current flowing between the object and the probe. Probe equipment. (7) The probe and the fine movement means are formed by etching on the same substrate, and the fine movement means finely moves the probe within a plane parallel to the substrate surface. probe equipment. (8) The substrate portion on which the probe and fine movement means are formed is separated from other substrate portions by etching except for a predetermined portion, and this predetermined portion is elastically deformed to form a substrate surface of the other substrate portion. 8. The probe according to claim 7, further comprising means for finely moving the substrate portion on which the probe and fine movement means are formed, which is configured to be able to swing in a vertical direction, and along this swinging direction. probe equipment. (9) In a probe device comprising a probe for recording information on an object surface and/or detecting information on the object surface, and a fine movement means for finely adjusting the position of the probe by finely moving the probe, the fine movement means comprises a cantilever-type actuator that drives the probe by deforming a beam holding the probe, a part that is elastically deformable with respect to a fixed part, and the actuator that is connected to the elastically deformable part by the actuator. A probe device characterized by having a driving part that moves linearly.