JP2000206126A - Minute cantilever and apparatus utilizing minute force - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make highly accurately and easily formable a minute cantilever having a low spring constant and a high resonance frequency by controlling the thickness by a semiconductor lithography technique, and forming the cantilever and a cantilever support stage of different materials on the same face. SOLUTION: A silicon active layer 4 of an SOI(silicon on insulator) wafer is anisotropically etched, thereby forming an active layer part 7 to be a cantilever support stage. A silicon oxide film 5 is etched thereby forming square through windows 8. Square prisms 9 are formed to a silicon substrate 6 with using the oxide film 5 as a mask. A cantilever material such as silicon nitride or the like is vapor deposited to form a cantilever film 10, on which a photoresist pattern for the cantilever is formed by a photolithography technique. The cantilever is formed by reactive ion etching with using the photoresist pattern as a mask. The silicon substrate part 6 and silicon oxide film 5 are removed at the end. The minute cantilever with a probe 1' is thus formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cantilever used for detecting a small force such as an atomic force, and more particularly to a small cantilever having a short cantilever and a device for applying the same.

[0002]

2. Description of the Related Art In recent years, the progress of the information society has been remarkable,
There is a demand for the development of technology that can store more information. At present, in the field of research on disk-type file memories, higher densities of magnetic recording and optical recording are being promoted. 200
It is predicted that the recording density will be several tens of Gb / in ² in five years, and the above recording method is considered to approach the limit.

One of the ways to overcome this limitation is AFM.
(Atomic force microscope) There is a recording method. A very important factor in this recording method is a cantilever that detects an atomic force. At present, the resonance frequency of a cantilever having a small spring constant (<2 N / m) is about 80 KHz at the maximum, and this frequency is insufficient for high-speed reading. at least,
In order to achieve a read speed of 10 Mb / s, the spring constant must be small and the resonance frequency must be 5 MHz or more.

Until now, SOI (silicon on silicon) has been proposed as a proposal of a cantilever having a smaller spring constant.
Silicon cantilever using an insulator) wafer and an active layer as a cantilever has been replaced by J. of Vacuum Scie
nce and Technology) Volume B15 (1997) No. 788
Pp. 792, a silicon nitride cantilever formed by forming a silicon nitride film using a quadrangular pyramid formed on a silicon substrate by silicon anisotropic etching as a template, and the Journal of Vacuum Science.
J. of Vacuum Science and Techno
A8 (1990) pp. 3386-3396.

FIG. 2 is a perspective view showing the structure of the cantilever proposed in these proposals. Reference numeral 1 denotes a cantilever, at the tip of which a probe 1 'is formed. Reference numeral 3 denotes a cantilever support made of a glass member. The cantilever 1 and the probe 1 ′ can be integrally formed by, for example, a semiconductor lithography technique for forming a silicon nitride film using a silicon mold. The base of the cantilever 1 is connected to the cantilever support 3. Must be, for example,
Both are integrated by anodic bonding technology.

[0006]

In the above-mentioned prior art, it is very important how much the size of the formed cantilever deviates from the design value and the error. In order to increase the speed, it is necessary to shorten the length of the cantilever and further reduce the thickness. Specifically, in order to achieve the above-mentioned target (resonance frequency> 5 MHz, spring constant <2 N / m), the length of the cantilever <5 μm and the thickness <
It must be 0.1 μm.

In a silicon cantilever using an SOI (silicon on insulator) wafer, it is very difficult to control the thickness of the cantilever because an active layer of silicon is etched. In addition, in the above-described cantilever manufacturing process of the silicon nitride film using the silicon mold, since the anodic bonding method is used for bonding the cantilever 1 and the glass support 3, a large alignment error (about 25 μm) occurs between them. . As is apparent with reference to FIG.
Even if you intend to make a cantilever with a length of μm,
If there is a misalignment, the cantilever becomes substantially 35 μm. This lowers the resonance frequency of the cantilever, and the alignment error needs to be 1 μm or less, which is a very difficult problem with the prior art. Also in an atomic force microscope, a cantilever having a high resonance frequency has a small minimum detection power, and the force detection sensitivity is improved.

An object of the present invention is to solve the technical problems of the prior art, provide a highly accurate film thickness control method, and provide a highly accurate alignment function in which the alignment error between the cantilever and the support is 1 μm or less. Has a cantilever structure that can be held,
An object of the present invention is to provide a micro cantilever having a high resonance frequency and a low spring constant, and to provide a micro force utilizing device using the micro cantilever.

[0009]

In order to achieve the above object, the cantilever and the cantilever support stand are automatically placed on the same surface by adopting a method in which semiconductor lithography technology can be used in all processes and the thickness can be controlled. It can be formed into a structure.

[0010]

1A is a perspective view of a cantilever proposed by the present invention, and FIG. 1B is a sectional view of the same. Reference numeral 1 denotes a cantilever, at the tip of which a probe 1 'is formed. 2 is a cantilever support. The cantilever 1 and the probe 1 'are integrally formed by a semiconductor lithography technique as in the prior art, and the cantilever support 2 for holding the base of the cantilever 1 is also integrated by the semiconductor lithography technique. Has become.

In the present invention, the cantilever 1 and the cantilever support 2 can be precisely aligned by using the substrate to which the semiconductor lithography technique is applied as it is as the cantilever support. Of course, the thickness of the cantilever can be accurately formed by means such as vapor deposition, and the probe 1 'can be integrally formed during the process of forming the cantilever. Hereinafter, a specific forming procedure will be described.

Embodiment 1 FIG. 3 shows a process flow using an SOI (silicon-on-insulator) wafer. An SOI wafer is prepared as shown in FIG. As is well known, the SOI wafer has a three-layer structure including a silicon substrate 6, a silicon oxide film 5 formed on the substrate 6, and a silicon active layer 4 formed on the silicon oxide film. First, as shown in FIG. 3B, the silicon active layer 4 is anisotropically etched using a KOH etchant to form a portion of the active layer 7 to be a cantilever support. Next, FIG.
As described above, the silicon oxide film 5 is etched with hydrofluoric acid to form a square through window 8. As shown in FIG.
Using the oxide film as a mask, a pyramid 9 is formed on the silicon substrate 6 by anisotropic etching using a KOH etching solution. Next, as shown in FIG. 3E, a cantilever material 10 (for example, silicon nitride) is deposited by low-pressure chemical vapor deposition (LP-CVD) to form a cantilever film. A photoresist pattern for the cantilever 1 is formed by a lithography technique (here, a stepper is used). Using the resist pattern as a mask, the cantilever 1 is formed by reactive ion etching. Finally, as shown in FIG. 3F, the silicon substrate 6 and the silicon oxide film 5 are removed by etching to produce a cantilever.

In this manner, a small cantilever having a length of <10 μm and a thickness of <0.1 μm with the probe 1 ′ can be formed with high reliability.

The sharpening of the probe 1 'can be carried out by low-temperature oxidation and oxide film etching, which are conventional techniques. The cantilever material 10 includes silicon nitride, a silicon oxide film, polysilicon formed by a plasma CVD method,
Alternatively, a metal film or the like can be used. When the cantilever is used, gold or platinum is vapor-deposited on one or both sides.

In this embodiment, it is effective to sharpen a quadrangular pyramid mold for forming a probe by low-temperature oxidation and etching. Further, the cantilever and the probe may be formed of a multilayer film.

Embodiment 2 FIG. 4 shows an example of a process using a silicon wafer 30 instead of an SOI wafer. Basically, the process is the same.

First, as shown in FIG. 4A, a silicon wafer 30 is prepared. As shown in FIG. 4B, the silicon wafer 30 is anisotropically etched using a KOH etching solution to form a portion 7 '(a portion above the broken line) of a structure to be a cantilever support. However, in this embodiment, since there is no silicon oxide film 5, it is necessary to pay attention when the etching is stopped. As will be apparent from the description of the subsequent steps, the etching depth for forming the portion 7 'of the structure to be the cantilever support is determined by the depth of the portion 7' (the portion above the broken line). It is necessary to make the oxide film 11 thicker than the thickness. Next, as shown in FIG. 4C, after an oxide film 11 is formed, the silicon oxide film 11 is etched with hydrofluoric acid to form a square through window 8. As shown in FIG. 4D, the pyramid 9 is formed on the silicon substrate 30 by anisotropic etching using the oxide film 11 as a mask and a KOH etching solution. Next, as shown in FIG. 4E, a cantilever material 10 (for example, silicon nitride) is formed by low-pressure chemical vapor deposition (LP-CVD) to form a cantilever film. A photoresist pattern for the cantilever 1 is formed by a lithography technique (here, a stepper is used). Using the resist pattern as a mask, the cantilever 1 is formed by reactive ion etching. Finally, the silicon substrate 30 and the silicon oxide film 11 are removed by etching as shown in FIG.
A cantilever integrally formed with a portion 7 '(a portion above a broken line) of a structure to be a cantilever support is produced. In this case, unlike the embodiment of FIG. 3, since the silicon substrate 30 and the silicon oxide film 11 are etched, attention should be paid to the selection of the etching material, the etching rate, etc. It is necessary to make the bottom face coincide with the bottom face of the part 7 'of the structure to be the cantilever support.

FIG. 5 is a diagram for explaining an example of a device for this purpose. For simplification, only the right half is shown.
(A) shows the result of the step of removing the Si substrate 30 by etching, and (b) shows the result of the step of removing the silicon oxide film 11 by etching. Si
In the step of removing the substrate 30 by etching, the thickness of the portion of the cantilever 1 is monitored by light transmission, and when the situation where only the cantilever material 10 and the silicon oxide film 11 are detected is detected, the thickness of the silicon oxide film 11 is determined. It waits for the removal of the Si substrate 30 by etching to progress considerably. As a result, as shown in (a), etching is performed leaving the Si substrate 30 and the silicon oxide film 11 in the portion 7 '(the portion above the broken line) of the structure to be a cantilever support. Next, the process proceeds to removal of the silicon oxide film 11 by etching. In this case, by controlling the etching time according to the thickness of the silicon oxide film 11, (b)
As shown in FIG. 7, the portion of the cantilever 1 of the silicon oxide film 11 is removed, leaving a portion 7 'of a structure to be a cantilever support and the silicon oxide film 11 covered by the portion. When the silicon oxide film 11 is etched (the portion above the broken line), the Si substrate 30 is also slightly etched. Therefore, it is preferable to control the etching time in the step (a) in consideration of this.

Strictly speaking, the bottom surface of the cantilever 1 and the portion 7 'of the structure to be a support may not be flush with each other. A plane can be realized.

Also in this embodiment, it is effective to sharpen a quadrangular pyramid mold for forming a probe by low-temperature oxidation and etching. Further, the cantilever and the probe may be formed of a multilayer film.

Embodiment 3 FIG. 6 shows an AFM as an example of an application device of a micro cantilever.
It is the schematic which shows an example of the recording device using the (atomic force microscope) technique. The device includes an AFM head, a rotation mechanism system, and a control system. AFM head is probe 1 '
AFM probe 2 consisting of a cantilever and a cantilever 1
7. An optical lever detection system for detecting a force applied to the probe 1 ', a recording piezoelectric element 25, and a mechanism system (XYZ scanner 14) for controlling the probe 27. The optical lever detection system basically includes a laser source 23 and a position detector 24 of the light beam 12 as shown in the figure. A 30 nm gold thin film or platinum is deposited on the back surface of the cantilever (the surface where the probe 1 'is not attached) to increase the laser reflectance. Here, although the coarse movement mechanism, the probe approach / retreat mechanism, and the probe seek mechanism are omitted, they are naturally provided. The rotating mechanism system includes a motor 22, a bearing (omitted), and a disk table (omitted). The disk 26 is placed on this table to perform recording, reading, and erasing. The control system 20 obtains the position information of the probe 1 ′ from the signal 15 obtained from the position detector 24 of the light beam 12, and performs position control, detection of a recording signal, generation of a write signal, and the like. Numeral 16 denotes probe 1 'capture of position information, tracking, and probe 1'.
This is a detection / control system that performs three-dimensional position control. The disk has a recording substrate 26 having a surface structure with a guide groove placed on a disk table, on which reading, writing, erasing and the like are performed.

When the guide groove is a V-shaped groove, the laser beam 12 reflected from the back surface of the cantilever 27 enters the position detector 24. This position detector 24 is a two-dimensional position sensor or 4
A split photodetector may be used. Here, the latter photodetector is shown. When the V-groove is twisted on the probe 1 ', it is detected as a lateral force. This force is detected by computing the output signals from the four photodetectors of photodetector 24 to detect the direction of twist in a conventional manner. As the probe 1 'moves away from the center of the V-groove, the output signal changes in the positive or negative direction. This characteristic changes almost linearly in the V groove. Utilizing this characteristic, a deviation from the center of the V-groove is detected from a change in the lateral force, and the XYZ scanner 14 is controlled to always control the probe 1 'to be at the center of the V-groove. On the other hand, when the probe 1 'comes over the recording bit, the probe 1' penetrates deeply into the recording substrate 26 to detect the recording bit. At this time, the increment of the penetration amount of the probe 1 'is dZ. This amount is calculated by a network provided in the photodetector 24 and detected as a contact signal. 10k
The movement below H is caused by distortion of the disk 26, and the servo circuit 16 controls the probe 1 'in the Z direction using the XYZ scanner 14. The probe 1 'is controlled so as to be in contact with the disk 26 with a constant force.
A fast change of 1 MHz or more is judged as a signal, taken into the control system as information, and read out.

As described above, high-speed reading was not possible with a conventionally used cantilever, but a signal of 10 MHz or more can be read by using the cantilever of the present invention. Writing can be performed by using polycarbonate for the recording substrate. By using the pressing piezoelectric element 25, pits (concave structure) can be written on the polycarbonate substrate at high speed by the pressure modulation of the probe 1 '. When the probe of the present invention is used, an AFM recording system is used to rotate a super-high-density recording bit string having a track pitch or track length of 0.5 μm or less to a rotating mechanism system having a ball bearing or a liquid bearing conventionally used. Can be read at high speed without reading errors.

Further, if the probe of the present invention is used for detecting the atomic force of a probe microscope, the sensitivity for detecting the atomic force can be improved by about one to two orders of magnitude. As a result, the spatial resolution is improved by one digit or more compared to the current state. Furthermore, high-sensitivity measurement of one digit or more can be performed in the detection of physical properties of a sample. The scope of the present invention is a microscope using an atomic force such as an atomic force microscope, a magnetic force microscope, a capacity microscope, a near-field light microscope, a Kelvin force microscope, a Maxell microscope, a scanning heat microscope, and a potentiometer.

Embodiment 4 FIG. 7 shows an AFM as an example of an application device of a micro cantilever.
FIG. 8 is a schematic diagram showing another example of a recording apparatus using (atomic force microscope) technology, and FIG. 8 is an explanatory diagram of the optical system.

Reference numeral 122 denotes a motor for driving the disk, 102
Denotes a disk recording medium, and the recording medium 102 is rotationally driven by a motor 122. 1 'is a probe, and 1 is a cantilever. In these, a probe 1 ′ is formed at the tip of the cantilever 1 by Si doped with an impurity element, and the cantilever 1 is attached to the base thereof, and is formed together with the base as an integral structure by a semiconductor manufacturing technique. When the pressure modulation recording is performed, a material softer than the probe 1 ′ is naturally selected for the disk recording medium 102. 25
Is a piezoelectric element, which holds the base of the cantilever 1 at one end. The tip of the probe 1 ′ has, for example, a curvature radius of 20 nm.
It is formed below.

Reference numeral 108 denotes a pulse voltage source, and the recording medium 1
02 is supplied with a signal 150 to be recorded, and a voltage pulse 19 is applied to the piezoelectric element 25 in response to the signal 150.
When the voltage pulse 19 is applied to the piezoelectric element 25, a force F expressed by the following equation is applied to the probe 1 ', and the probe 1' is pushed into the recording medium 102 side, and the mechanical pressure causes the recording medium 102 Has a concave structure 103 corresponding to a signal to be recorded.

F = kX where k is the spring constant of the cantilever, and X is the cantilever 1
Is the amount of warpage (displacement). Now, assuming that the spring constant k and the displacement X are 1 N / m and 1 μm, respectively, the force F acting on the probe 1 ′ is 10 ⁻⁶ N. The magnitude of this force depends on the material of the recording medium 102, but is large enough to cause plastic deformation as recording data.

The piezoelectric element 25 is held by the Z-fine movement device 124. The Z-fine movement device 124 is held by the Z-coarse movement device 126. The Z-coarse movement device 126 is held by a radial drive device 128 of the recording medium 102. Reference numeral 120 denotes a general control device, which receives a recording instruction signal W, a reading instruction signal R, and a recording signal WD from outside and outputs the reading signal RD to outside. Further, the general control device 120 outputs a drive signal 121 to the motor 122 and a drive signal 1 to the radial drive device 128.
27, a control signal 129 to the Z drive control unit 130 and a signal 150 to be recorded on the recording medium 102 corresponding to the recording signal WD are output, and the output 100 of the position sensor 49 of the cantilever rotation angle detector 50 is input.
A read signal obtained from the Z drive control device 130 is sent to the general control device 120 via a signal line 151, and is output to the outside as a read signal RD. The control signal 129 is used as a trigger for setting an initial state of a relative positional relationship between the probe 101 and the recording medium 102.

Motor 122, Z-fine movement device 124, and
The Z-coarse movement device 126 has respective drive signals 121, 12
Driven by 3,125 and 127. Motor 12
2 and the radial driving device 128 are held by a recording / reproducing device main body (not shown). Therefore, probe 1 '
Moves on the surface of the recording medium 102 according to the drive signals 123, 125, and 127, and forms the concave structure 103 corresponding to the signal 150 to be recorded on the surface of the recording medium 102 when the voltage pulse 19 is applied.

The recording / reproducing apparatus according to the present embodiment is not limited to the apparatus for rotating the recording medium 102 as shown in the figure, but may be an apparatus for driving in the XY direction.

Next, the cantilever rotation angle detector 50 will be described. The rotation angle detector 50 functions to read recorded information and is also used to set an initial state of the probe 1 '.

Reference numeral 41 denotes a semiconductor laser, and reference numeral 42 denotes a collimator lens. The laser light emitting surface of the semiconductor laser 41 is located at the focal position of the collimator lens 42. Therefore, the laser light emitted from the semiconductor laser 41 is converted into parallel light by the collimator lens 42. The light beam of the parallel light passes through the beam splitter 45, and is condensed by the objective lens 46 to focus on the tip of the cantilever 1 '. The light reflected on the surface of the tip of the cantilever 1 ′ is converted into parallel light by the objective lens 46. If the reflecting surface is perpendicular to the optical axis of the objective lens 46, the light flux of the reflected light returns the incident light path to the cantilever 1 as it is, and reaches the beam splitter 45. The reflected light is bent by 90 ° in the optical path by the beam splitter 45 and reaches the position sensor 49. When the reflection surface is rotated within a predetermined minute range from the vertical with respect to the optical axis of the objective lens 46, the light flux of the reflected light is slightly deviated from the optical path incident on the cantilever 1, but the beam splitter 45 is effective. Return within range,
The optical path is bent by 90 ° by the beam splitter 45 and reaches the position sensor 49. The cantilever rotation angle detector 50 is held by a recording / reproducing apparatus main body (not shown), similarly to the motor 122 and the radial driving device 128.

Here, the initial setting of the probe 1 'will be briefly described. In this embodiment, the rotation angle detector 50 has no output from the position sensor 49 when the cantilever 1 is in a free state, in other words, there is no reflected light from the cantilever 1 on the photodiode of the position sensor 49. It is assumed to be. In this state, when the recording instruction signal W or the reading instruction signal R is given to the general control device 120, the general control device 120
A control signal 129 to 0 is output. Z drive controller 1
30 receives this signal and sends a drive signal 1 to the Z-coarse movement device 126.
Give 25. Thereby, the cantilever 1 becomes the recording medium 1
02 approaches the surface and begins to rotate by receiving force from the surface. As a result, the reflected light SP from the cantilever 1 appears on the detection surface (photodiode) of the position sensor 49. Therefore, the Z drive control device 13
0 is the position sensor 49 after receiving the control signal 129.
When the coarse movement operation is stopped at the stage when the output changes to the predetermined state, the initial setting of the probe 1 is completed.

Next, the recording operation will be described. When the initialization is completed in accordance with the recording instruction signal W as described above, the completion of the initialization is sent to the general control device 120 via the signal line 151, for example. In response to this, the general controller 120 sends a signal 150 to be recorded according to the input recording signal WD to the pulse voltage source 108 and sends a drive signal 121 to the motor 122. As a result, a concave structure 103 is formed in the recording medium 102 and the recording signal W
Recording according to D is performed. In this case, the concave structure 103 is formed and the cantilever 1 rotates. This is detected by the output of the position sensor 49 and the Z-fine movement device 124 and the Z-coarse movement device 126 cause the cantilever 1 to rotate.
, The force acting on the probe 1 ′ can be kept constant.

Next, the read operation will be described. When the initialization is completed as described above in response to the read instruction signal R, for example, the completion of the initialization is sent to the general control device 120 via the signal line 151. In response, the general control device 120 sends a drive signal 121 to the motor 122 and sends a drive signal 127 to the radial drive device 128.
give. Thus, the probe 1 'can be moved along the recording track of the recording medium 102. Of course, the tracking itself is an important technique, but various techniques have already been proposed, and an appropriate one can be selected and adopted. For example, U.S. Pat. No. 5,808,977 proposed by the inventors of the present application proposes a tracking method using an optical lever system, and thus can be effectively used. Depending on the rotation of the recording medium 102, there are times when the probe 1 'comes to the position of the concave structure 103 and times when it does not. In this embodiment, since the initialization is performed on the assumption that the position is not the position of the concave structure 103, the probe 1 'is
At the position 3, the reflected light of the cantilever 1 received by the position sensor 49 changes abruptly. If this is detected, the presence of the concave structure 103 can be detected, and if this change is sent as a read signal to the general control device 120 via the signal line 151, the read signal RD can be obtained. Also in this case, as in the case of recording, if the rotation of the cantilever 1 is detected and the cantilever 1 is made to follow by the Z-fine movement device 124 and the Z-coarse movement device 126, the probe 1 '
Can be kept constant.

If this cantilever is used for AFM recording,
Ultra high-density recording of 1 Tbit (10 ¹² bits) / in ² is possible, and the reading speed can be increased to 10 Mb / s or more.

Next, the cantilever rotation angle detector 50 will be described in more detail with reference to FIG.

The laser light emitting surface of the semiconductor laser 41 is located at the focal point of the collimator lens 42. Therefore, the laser light emitted from the semiconductor laser 41 is converted into parallel light by the collimator lens. The light flux of the parallel light enters the polarization beam splitter 45. Laser light emitted from a semiconductor laser is generally linearly polarized light. Now, it is assumed that the plane of polarization of the laser light emitted from the semiconductor laser of FIG. 8 is oriented in a direction parallel to the paper. Then, the polarization beam splitter 45 converts almost all the laser light into the cantilever 1 when the laser light enters as shown in FIG.
It is adjusted to reflect in the direction of. The light beam reflected by the polarization beam splitter 45 is converted into circularly polarized light by the quarter-wave plate 44, and then condensed by the objective lens 46 to focus on the surface of the cantilever 1. The light reflected on the surface of the cantilever 1 is converted into parallel light by the objective lens 46 this time. If the reflection surface of the object to be measured is perpendicular to the optical axis of the objective lens, the light beam of the reflected light returns the incident light path to the cantilever 1 as it is, and reaches the polarization beam splitter 45. However, at this time, since the light passes through the quarter-wave plate 44 in the middle and is circularly polarized light rotating in the opposite direction to the incident light, the reflected light passing through the quarter-wave plate 44 is polarized light orthogonal to the paper surface. It is linearly polarized light having a wavefront. Almost all the reflected light that has entered the polarization beam splitter 45 passes through the polarization beam splitter 45 and reaches the position sensor 49. The change in the position of the light flux of the reflected light that reaches the position sensor 49 is detected as, for example, a change in the position of a light spot formed on a two- or four-division photodiode.

Here, it is assumed that the cantilever 1 is rotated by an angle θ in the plane of the drawing as shown in FIG. In addition, the objective lens 4
It is assumed that the change in distance between 6 and the cantilever 1 is negligible. In this case, the center of the light beam reflected by the surface of the cantilever 1 is reflected by the position sensor 49 in a direction at an angle of 2θ to the center of the light beam of the incident light as shown in FIG. Therefore, assuming that θ is sufficiently small and the focal length of the objective lens 46 is L, the luminous flux center of the reflected light that has reached the objective lens 46 is 2θ from the luminous flux center of the incident light.
L is biased. The reflected light is converted by the objective lens 46 into parallel light having a deviation of the center of the light flux, and passes through the polarization beam splitter 45 to reach the position sensor 49. Therefore, if the deviation of the center of the light beam is sufficiently smaller than the diameter of the light spot, the output of the position sensor 49 placed at this position changes in proportion to the displacement angle θ.

Other Embodiments Further, the cantilever of the present invention can be applied to fine processing. For example, it can be used as AFM lithography. In this case, the probe 1 'and the cantilever 1 need to be formed of a conductive film or a conductive film is deposited. In addition, it can be applied to processing using force and indentation. In addition, even with a microscope using an atomic force such as an AFM, force detection with high sensitivity can be realized.

The material of the cantilever 1 is not limited to the silicon nitride film of the embodiment, but may be formed of, for example, a silicon oxide film.

[0043]

As described above, according to the present invention, 2
A minute cantilever having a low spring constant of N / m or less and a high resonance frequency of 1 MHz or more can be easily formed with high accuracy.

[Brief description of the drawings]

FIGS. 1A and 1B are a perspective view and a sectional view showing a basic configuration of a cantilever according to the present invention.

FIG. 2 is a perspective view showing a configuration of a cantilever using anodic bonding in a conventional technique.

FIG. 3 shows an S for manufacturing a cantilever according to the present invention.
The figure which shows the process flow using an OI wafer.

FIG. 4 is a view showing a process flow using a silicon wafer for manufacturing a cantilever according to the present invention.

FIG. 5 is a diagram illustrating a process flow for etching a silicon substrate portion and a silicon oxide film portion.

FIG. 6 is a schematic diagram showing an embodiment of an ultra-high-density recording device using an AFM as an example of a cantilever application device according to the present invention.

FIG. 7 is a schematic diagram showing another embodiment of an ultra-high-density recording device using an AFM as an example of an application device of a micro cantilever according to the present invention.

FIG. 8 is an explanatory diagram of the optical system of FIG. 7;

[Explanation of symbols]

1 ... cantilever, 1 '... probe, 2 ... cantilever support,
3 ... Glass support, 4 ... Silicon active layer, 5 ... Insulator (silicon oxide), 6 ... Silicon substrate, 7 ... Support, 8
... square window, 9 ... square pyramid hole, 10 ... cantilever film (silicon nitride), 11 ... silicon oxide, 12 ... light beam,
14 ... XYZ scanner, 15 ... Output signal from photodetector, 1
6 ... Detection / control system (servo circuit), 17 ... Z direction probe position control signal, 18 ... XY direction probe position control signal, 19 ...
Write signal, 20: recording device control system, 21: rotation mechanism control signal, 22: motor, 23: laser source, 24: position detector (position sensor), 25: writing (pressure modulation) piezoelectric element, 26 ... Recording air disk (polycarbonate), 27: micro cantilever of the present invention, 30: semiconductor substrate (silicon substrate).

Continued on the front page (72) Inventor Atsushi Kikukawa 2520 Akanuma, Hatoyama-cho, Hiki-gun, Saitama Prefecture Inside Hitachi, Ltd.Basic Research Laboratories Co., Ltd. Inside the laboratory (72) Inventor Hajime Koyanagi 2520 Akanuma, Hatoyama-cho, Hiki-gun, Saitama Prefecture Inside the Basic Research Laboratory, Hitachi, Ltd. (72) Inventor Yomasa Onisato 2-6-1 Otemachi, Chiyoda-ku, Tokyo (Japan Building) Hitachi Construction Machinery Co., Ltd. (72) Inventor Ken Murayama 2-6-1, Otemachi, Chiyoda-ku, Tokyo (Nippon Building) Hitachi Construction Machinery Co., Ltd. F-term (reference) 2F063 AA43 CA12 DA01 DD02 EA16 EB16 EB05 EB15 EB23 JA04 2F069 AA60 DD15 GG04 GG06 GG07 HH04 HH30 MM04 RR03 5D119 AA11 AA22 BA01 BB02 CA20 DA01 DA05 EC24 FA05 KA01

Claims (9)

[Claims] 1. A cantilever for detecting a minute force, wherein a probe is formed at a tip of the cantilever, and a support base for supporting the cantilever in substantially the same plane as a surface of the cantilever on which the probe is formed. Are formed and made of different materials or materials. 2. The micro cantilever according to claim 1, wherein said support base is formed of a semiconductor substrate. 3. The micro cantilever according to claim 1, wherein said cantilever is formed of a silicon nitride film or a silicon oxide film. 4. The micro cantilever according to claim 1, wherein said cantilever has a structure covered with a conductive film. 5. The micro cantilever according to claim 1, wherein the probe is formed in a direction opposite to a thickness direction of the support table. 6. The micro cantilever according to claim 5, wherein said probe is formed using a quadrangular pyramid formed by anisotropic etching of a silicon substrate as a template. 7. The micro cantilever according to claim 1, wherein the cantilever and the probe are formed of a multilayer film. 8. The microcantilever according to claim 6, wherein the tip of the quadrangular pyramid forming the probe is sharpened by low-temperature oxidation and etching. 9. A microscope equipped with a micro cantilever, a micro force utilizing device for measuring and processing such as ultra-high density recording, micro-processing, etc., wherein said micro cantilever has a probe formed at the tip of the cantilever. A micro-force utilization device characterized in that a support base for supporting the cantilever is formed on substantially the same plane as the cantilever surface on which the probe is formed, and these are made of different materials or materials.