JPH07311207A - Spm cantilever and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide an SPM (a scanning-probe-microscope) cantilever capable of satisfying both lever characteristics and probe characteristics required in various applications and usages and manufacture thereof. CONSTITUTION:An SPM cantilever is composed of a.cantilever bearing section 103 consisting of glass, Si, etc., a cantilever section 101, in which one end is fixed onto the bearing section 103 by anodic joining through adhesives and which is made up of silicon, silicon nitride on the like, and another probe section 102, which is mounted on a rear as the reverse side to the bearing section 103 to the cantilever section 101 as the free end of the cantilever section 101, to the cantilever section 101. Materials having various characteristics such as light transmission, conductivity, hardness, etc., are selected and used properly in accordance with applications as the forming material of the probe section 102.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an SPM cantilever used in a scanning probe microscope such as an atomic force microscope and a method for manufacturing the SPM cantilever.

[0002]

2. Description of the Related Art Conventionally, a scanning tunneling microscope (STM: Binning Tunneling Microscope) has been used as an apparatus capable of observing a conductive sample with a resolution of atomic size order.
Since it was invented by G. and Rohrer et al., it has been used in various fields as a microscope for observing surface irregularities of atomic order. However, in STM, observable samples are limited to conductive ones.

Therefore, an atomic force microscope is used as a microscope capable of observing an insulating sample, which has been difficult to measure with STM, with an accuracy of atomic size order while utilizing elemental technologies such as servo technology in STM. (AF
M) was proposed. This AFM is disclosed, for example, in Japanese Patent Laid-Open No. 62-
130302 (patent applicant: IBM, inventor: G. Binnig, title of invention: method and apparatus for forming an image of a sample surface).

The structure of the AFM is similar to that of the STM, and the scanning probe microscope (SPM) is used.
It is positioned as one of the measures. In the AFM, a cantilever having a sharp protrusion (probe) at its free end is placed facing or close to the sample, and is displaced by the interaction force acting between the atom at the tip of the probe and the sample atom. X-ray the sample while measuring the function of the cantilever beam electrically or optically.
By scanning in the Y direction and relatively changing the positional relationship between the cantilever and the probe, it is possible to three-dimensionally capture the unevenness information of the sample in the atomic size order.

As a cantilever chip for a scanning probe microscope (SPM) in the above-mentioned AFM, etc., TRAlbrecht et al. Proposed a cantilever made of a silicon oxide film which can be manufactured by applying a semiconductor IC manufacturing process. Since (Thonas R. Albrechtand Calvin F.
Quate: Atomic resolution imaging of a nonconducto
r Atomforce Microscopy J. Appl. Phy. 62 (1987) 2599
It is possible to manufacture it with high precision in the micron order and with excellent reproducibility. Further, such a cantilever chip can be manufactured by a batch process, and cost reduction is realized. Therefore, at present, the cantilever chip manufactured by applying the semiconductor IC manufacturing process is the mainstream.

Next, with reference to FIG. 14, a method of manufacturing a silicon nitride film-made AFM cantilever applying a semiconductor IC manufacturing process which has been conventionally performed will be described. First, as shown in (A) of FIG.
00) Silicon nitride film pattern 9 on Si substrate 901
02 is provided to form a start substrate 900. Next, FIG.
As shown in FIG. 4B, by using the silicon nitride film pattern 902 as an etching resistant mask, the Si substrate 901 is subjected to wet anisotropic etching using KOH or the like, so that the Si substrate 901 is searched for a cantilever. A quadrangular pyramid-shaped replica hole 903, which is a mold of the needle portion, is formed. Thereafter, as shown in FIG. 14C, the silicon nitride film pattern 902 is once removed, and a silicon nitride film 904 serving as a cantilever base material is newly deposited on the Si substrate 901. Further, as shown in FIG. 14D, the silicon nitride film 904 is selectively etched into a cantilever shape to form a cantilever pattern 905.
Next, as shown in FIG. 14 (E), a Pyrex glass 906 serving as a support member of the cantilever is anodically bonded to a predetermined region on the cantilever pattern 905. Subsequently, as shown in FIG. 14F, the Si substrate 901 is removed by etching to obtain an AFM cantilever 907 including a supporting portion, a lever portion, and a probe portion.

Therefore, the AFM manufactured by this manufacturing method
The cantilever is composed of a glass support part, a probe part and a cantilever part which are integrally formed of a silicon nitride film. The AFM cantilever thus constructed can be manufactured with high accuracy in the micron order and with very high reproducibility, and moreover, since the probe is formed of a hydrophilic silicon nitride film as a material property, It is suitable for AFM measurement in a liquid effective for biological samples.

On the other hand, recently, a near-field microscope having a resolution exceeding the diffraction limit by using an evanescent wave [SNOM: Scanning Near-field Optical Micros]
[Cope] measurement is drawing attention. This SNOM is S
Similar to TM and AFM, it is a kind of SPM. It utilizes the property that the evanescent wave "localizes in the region of a size smaller than the wavelength and does not propagate in free space." This is a measurement method in which an optical image with extremely high resolution is obtained by scanning a certain probe.

The measurement principle of SNOM is as follows. First, the probe is brought close to the surface of the measurement sample up to a distance of about 1 wavelength or less, and a map of the light intensity passing through the minute aperture at the tip of the probe is created to measure the measurement sample. A resolution is made. Several methods have been proposed for SNOM, and roughly two methods have been proposed. One is called a collection method, which is a method in which an evanescent wave that passes through the sample and is localized near the sample surface when light is irradiated from below the sample is detected through a probe to form an SNOM image. The other method is a so-called emission method in which light is emitted to a sample from a probe having a minute aperture and light transmitted through the sample is detected by a photodetector installed under the sample. This is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-291310 (AT & T, RE Betzig).

It has been reported that the above-mentioned AFM cantilever having a silicon nitride film probe can be applied to this SNOM measurement (NF van Hulst, MHPMoe).
rs, OFJMoordman, RGTack, FBSegerink, B.Bolge
r: Near-field optical microscope using a silicon-
nitride probe Appl. Phys. lett. 62,461 (1993)). That is, since the silicon nitride film has optical transparency,
The AFM cantilever with a silicon nitride film probe is
In this way, it is also applicable to SNOM measurement.

On the other hand, as the AFM measuring method, a contact method in which a sample and a probe are brought close to each other by about 1 nm to perform measurement,
There are a non-contact method in which measurement is performed with a distance of 10 nm, and a tapping method in which measurement is performed while lightly tapping the sample surface with a probe. Among these measurement methods, the non-contact method and the tapping method require the use of a rigid cantilever.

In order to manufacture a rigid cantilever, it is necessary to make the lever film thick. As such an AFM cantilever, one in which a probe, a lever and a support part are integrally formed of silicon is widely known (for example, , O. Wolter,
Th.Bayer, and J. Greschner: Micromachined silicon se
nsors for scanning force microscopy J. Vac. Sci. Te
chnol. B9 (2), May / Apr 1991).

Since this silicon integrally-formed cantilever is manufactured by using the same semiconductor manufacturing technology as that described above, it can be manufactured with high precision in the micron order and with very high reproducibility, and the lever is made of a silicon substrate. It is easy to make thick levers for forming. Further, since the probe is made of silicon, it is possible to add conductivity to the probe by diffusing impurities into silicon in advance, so that STM measurement, surface modification, and processing are also possible.

[0014]

[Problems to be Solved by the Invention]

[Disadvantages of Prior Art] SFM such as AFM for collectively forming a probe and a lever made of a silicon nitride film, which is given as a first conventional example, is used.
The drawbacks of the PM cantilever are shown below. First, the thickness of the cantilever is determined by the deposited film thickness of the silicon nitride film deposited after forming the replica hole, but in order to avoid cracks and warpage of the substrate caused by stress during the deposition of the silicon nitride film, the film thickness that can be deposited is Is limited to about 1 μm. Therefore, it is difficult to form a rigid cantilever effective for the above-mentioned non-contact method or tapping method measurement. Further, since the probe is made of an insulating silicon nitride film, it is difficult to apply it to STM measurement, surface modification, processing and the like.

Furthermore, in the cantilever made of a silicon nitride film, in order to avoid the warp of the lever after the etching removal of the base substrate, the composition of the silicon nitride film to be used contains Si and nitrogen which are used in a usual semiconductor IC. It is necessary to use one having a higher Si content ratio than that having a ratio of 3: 4. We have found that in such a silicon nitride film having a high Si content ratio, the light transmittance is deteriorated due to the light absorption by Si in the short wavelength region of 400 nm or less.

As described above, the SPM cantilever integrally formed with silicon nitride can be used for SNOM measurement. However, when the fluorescence from the measurement sample is to be spectrally analyzed by SNOM, the probe in a wide wavelength range is used. Optical transparency is required. However, since the SPM cantilever has the probe and the lever formed together, the probe is formed of a silicon nitride film having a high Si content ratio, which deteriorates the light transmittance in the short wavelength region. Not suitable for measurement.

Further, in the conventional integrally-formed SPM cantilever, both the probe and the lever are made of silicon nitride. Therefore, the SNO cantilever is used by using this cantilever.
When M measurement is performed, part of the evanescent light incident from the tip of the probe and the scattered light from the probe propagates from the probe to the lever. Therefore, for SNOM measurement such as a photodetector provided above the probe. The amount of light that can be applied to the photodetector is 100
It will be as low as pW. Therefore, there is a problem that the loss of light detected by the photodetector is larger than that of light incident from the tip of the probe, and SNOM measurement with high sensitivity cannot be performed.

The AFM cantilever in which the probe, the lever, and the supporting portion are collectively formed of Si, which is given as a second conventional example, has a probe made of Si. Therefore, the AFM cantilever in water effective for biomaterials. In the measurement, in order to change Si, which is originally hydrophobic, to hydrophilic, a treatment such as coating a hydrophilic film on the surface of the probe is required, and the sharpness of the tip of the probe is impaired. is there. Further, since the supporting portion is integrally made of Si, a pattern must be formed on both front and back surfaces of the substrate during the production, and a special manufacturing apparatus is required.

Further, both the silicon nitride film-shaped probe and the silicon-made probe have weak mechanical strengths, and thus they have been conventionally applied to ultrafine mechanical processing techniques using such cantilevers. AFM cantilevers are not suitable. As described above, in the AFM cantilever manufactured by using the conventional semiconductor manufacturing technology, since the probe and the lever are formed of the same material, it is difficult to simultaneously satisfy the required characteristics as the probe and the required characteristics as the lever. there were.

[Object of the Invention] The present invention has been made in order to solve the above-mentioned problems in the SPM cantilever manufactured by using the conventional semiconductor manufacturing technology, and the lever required for various uses and usages. SPM satisfying both characteristics and probe characteristics
An object is to provide a cantilever and a method for manufacturing the cantilever. It is an object of the invention of claim 2 to form the SPM cantilever according to the invention of claim 1 by processing from one surface of the substrate without requiring a special device. It is an object of the invention according to claim 3 to provide an SPM cantilever suitable for spectrum measurement by SNOM measurement by allowing the probe to have high light transmittance even in a short wavelength region. It is an object of the invention according to claim 4 to provide an SPM cantilever applicable to STM measurement, surface modification and processing. According to the invention of claim 5, AFM measurement, STM measurement,
It is an object to provide an SPM cantilever that can be used for all SNOM measurements. It is an object of the invention of claim 6 to provide an SPM cantilever applicable to an ultrafine mechanical processing technique. In the invention described in claims 7 to 10, the evanescent light or the scattered light scattered at the tip of the probe can be sufficiently irradiated to the photodetector above the probe without escaping into the cantilever.
The purpose is to provide a PM cantilever. The invention according to claim 11 is the SP according to claims 1 to 6.
It is an object to provide a method for easily producing an M cantilever with good controllability.

[0021]

In order to solve the above problems, an SPM cantilever according to each of the first to sixth aspects of the present invention is provided with a support portion of a cantilever and a portion extending from the support portion. A cantilever, and a free end of the cantilever, and a probe portion provided on a back surface opposite to the supporting portion with respect to the cantilever. The beam and the probe part are configured by separate members.

The SPM cantilever having such a structure is
Since the probe part and the cantilever are formed by separate members,
The characteristics required for the probe and the cantilever can be easily provided according to the application and usage. That is, when Si is used as the cantilever forming member, a hard lever characteristic is obtained, and when a silicon nitride film is used, a soft lever characteristic is obtained. Then, it becomes possible to form a probe portion having various characteristics such as light transmittance, hydrophilicity, conductivity, and hardness with respect to each cantilever according to the application.

The SPM cantilever according to each of the seventh to tenth aspects of the present invention is the SPM cantilever according to the first or second aspect, wherein the probe portion is made of a member transparent to visible light. An optical shield is interposed between the cantilever and the cantilever. As the optical shield, a member having a refractive index smaller than that of the probe, a metal material, or a silicon oxide film is used.

As described above, the evanescent light incident from the tip of the probe and the scattered light scattered at the tip of the probe are provided by interposing the optical shield made of a member having a small refractive index, a metal material or a silicon oxide film. Of the S / N in the SNOM measurement by preventing the propagation of the light to the cantilever and reducing the loss of the light irradiating the photodetector arranged above the probe.
Can be improved.

In the method of manufacturing an SPM cantilever according to the present invention, a step of forming a replica hole for a probe portion on a surface of a substrate by an etching treatment, and a step of forming the replica hole on the substrate including the replica hole. Depositing a base material, etching the base material into a predetermined shape,
Forming a cantilever beam pattern on the substrate surface; bonding a cantilever support member to one end surface of the cantilever beam pattern formed on the substrate surface; and a cantilever beam formed on the substrate surface. The beam pattern is left by the thickness of the cantilever, and the back surface of the substrate is removed by etching. According to this manufacturing method, since the AFM cantilever can be manufactured only by processing from the substrate surface, it can be easily manufactured without requiring a special manufacturing apparatus.

[0026]

【Example】

[First Embodiment] Next, an embodiment will be described. 1A and 1B are views showing a first embodiment of an SPM cantilever according to the present invention. FIG. 1A is a perspective view thereof, and FIG. 1B is a transverse sectional view thereof. SPM cantilever 100 of this embodiment
Is composed of a cantilever portion 101, a probe portion 102 provided at the tip of the cantilever portion 101, and a support portion 103 provided at the base of the cantilever portion 101. Silicon or silicon nitride is suitable for forming the cantilever portion 101. As a member for forming the probe portion 102, a member having various characteristics such as light transmittance, conductivity, and hardness can be appropriately selected according to the application. Glass, Si or the like can be used for the support portion 103.

Next, as a first embodiment of a method of manufacturing an SPM cantilever having such a structure, a method of manufacturing a cantilever portion made of Si is shown in FIGS. 2A to 2F. It will be described based on. First start board 200
As shown in FIG. 2A, a silicon oxide film 202 is formed on the surface of a silicon wafer 201 having a plane orientation (100).
After forming, the n-type silicon wafer 203 having the same plane orientation (100) is bonded, that is, a so-called bonded SOI (Silicon On Insulator) substrate is used. Here, the silicon wafer 203 forms a cantilever, and its thickness is set according to the required characteristics of the lever. For example, its thickness is 2μ
It is about m.

Next, as shown in FIG. 2B, for example, RIE (Reactive Ion Etching) so as to penetrate the underlying silicon wafer 201 at the place where the probe portion on the surface of the start substrate 200 is to be formed. The replica hole 2 by etching the start substrate 200 using the
To form 04. Next, as shown in FIG. 2C, the probe forming member 205 is formed on the surface of the substrate by the low pressure CVD method, plasma C
Deposited using VD method, sputtering method, sol-gel method, etc.,
Next, after forming a mask pattern in the replica hole portion, the probe forming member 205 is etched to expose the substrate surface except the replica hole portion. Thereafter, as shown in FIG. 2D, after forming a cantilever beam forming mask pattern, the upper silicon wafer 2 is formed by RIE or the like.
03 is etched to form a cantilever beam pattern 211, and thereafter, a silicon oxide film 206 is formed on the surface of the cantilever beam pattern 211 made of the silicon wafer 203.

After that, as shown in FIG. 2E, the supporting portion 207 is formed on the cantilever beam pattern 21 of the start substrate 200.
1 is joined to one end of the surface. As a method of joining the supporting portions 207, for example, a method of anodic-bonding Pyrex glass (for example, Corning # 7740) having grooves formed on one side in advance, or a method of joining an appropriate supporting member with an adhesive or the like is used. . After that, as shown in FIG. 2F, the underlying silicon wafer 201 is removed by etching with an alkaline aqueous solution such as an aqueous solution of tetramethylammonium hydroxide (TMAH), and finally, a silicon oxide film 202 is removed with an aqueous solution of hydrofluoric acid. By removing 206, it is possible to obtain the SPM cantilever 212 according to the present invention, which is composed of, for example, a supporting portion 207 made of glass, a cantilever portion 208 made of silicon, and a probe portion 209.

Further, in the present embodiment, the probe forming member 20
Before depositing No. 5 on the substrate surface, the inside of the replica hole 204 is set to a temperature not higher than the glass transition temperature of silicon oxide, eg, 950 ° C.
Then, the tip of the replica hole 204 can be further sharpened by the oxidation treatment to form a sharpened oxide film, whereby a probe portion having a sharper tip can be formed.

Since the SPM cantilever thus formed uses the bonded SOI substrate as the start substrate 200, when the base silicon wafer 201 is removed by etching, the intermediate silicon oxide film 20 is surely removed.
Since the etching stops at 2, the cantilever pattern 21
1 is not impaired, and the thickness can be reliably controlled. Further, since the supporting portion 207 is joined from the front surface side of the substrate 200, it is possible to easily align the supporting portion 207 with the cantilever beam pattern 211.

Further, as the probe forming member 205, a light-transmissive silicon nitride film, a silicon oxide film, ITO, Sn
By using O ₂ or the like, SNOM measurement and its spectrum measurement are possible. As the silicon nitride film used in this case, it is better to use a silicon nitride film having a film composition in which the content ratio of Si and nitrogen is 3: 4, which is a stress-reduced silicon nitride film used in a conventional AFM cantilever. More suitable than a membrane. This is because the stress-reduced silicon nitride film has a large Si content ratio, and thus the light transmittance is reduced at a wavelength of 400 nm or less due to light absorption by Si.

Further, in the SPM cantilever for performing measurement (contact mode) in which the sample and the probe portion are in contact with each other, such as the tapping method, it is required that the probe portion is not easily worn or deformed by the contact. That is, the shape stability of the probe part is important. In this regard, regarding the hardness of the probe portion forming member 205, it is better to use a film composition having a Si: nitrogen content ratio of 3: 4 than that of a conventional low stress silicon nitride film. It is considered more suitable. This is based on the data obtained by the inventor through experiments.

On the other hand, if a conductive material is used as the probe forming member 205, it can be applied not only to AFM measurement but also to STM measurement or surface modification and processing such as atom and molecule manipulation using STM. Various kinds of metals can be used as the conductive material. Particularly, by using a refractory metal such as Mo or W and a silicide thereof, it becomes possible to perform high temperature heat treatment even after forming the probe forming member. There are few restrictions. By using the transparent electrode material such as ITO or SnO ₂ described above, AFM, SNOM, STM
It becomes possible to perform all the measurements of. Furthermore, by using a hard material such as SiC or diamond for the probe forming member 205, it is possible to apply it to an ultrafine mechanical processing technique such as scanning and shaving the surface of a workpiece.

As described above, the material suitable for various uses can be arbitrarily applied as the probe forming member according to the present invention.
Since the PM cantilever is configured so that the probe portion and the cantilever are formed of separate members, for example, the conventional probe portion and the cantilever beam are controlled such as controlling film stress to prevent warpage during formation of the cantilever. This is because it was almost unnecessary to consider the material restrictions that existed in the body type AFM cantilever.

[Second Embodiment] Next, the SPM according to the present invention
A second embodiment of the method for manufacturing the cantilever will be described with reference to the manufacturing process diagrams shown in FIGS. In FIGS. 3A to 3F, the members equivalent to or corresponding to the members shown in FIGS. 2A to 2F in the first embodiment correspond to the 300s instead of the 200s. It is shown with a reference numeral. Also in this embodiment, Si is used as the cantilever member. First, as the starting substrate 300, as shown in FIG.
A high-concentration p-type impurity diffusion layer 303 to be a cantilever formation portion is formed on a type silicon wafer 301. As the p-type impurity diffusion layer 303, for example, a boron diffusion layer having a surface concentration of 1 × 10 ^{19 to} 1.5 × 10 ²⁰ / cm ³ is used. Next, as shown in FIG. 3B, a replica hole 304 for forming a probe is formed so as to penetrate to the silicon wafer 301. In the first embodiment,
Although a dry etching method such as RIE was used for forming the replica hole, a wet etching method using a KOH aqueous solution may be used in addition to this in the present embodiment.

In the same manner as in the first embodiment, FIG.
As shown in (C) to (E), deposition and etching of the probe forming member 305, formation of the cantilever beam pattern 311, formation of the silicon oxide film 306, and joining of the glass substrate to be the support portion 307 are performed.

After that, the silicon wafer 301 is removed by etching with an ethylenediaminepyrocatechol aqueous solution (EDP). In this etching solution, since the etching rate of the high-concentration p-type impurity diffusion layer is significantly reduced, when the silicon wafer 301 is gradually etched and the cantilever beam pattern 311 made of the p-type impurity diffusion layer 303 is exposed, Etching stops automatically.
And finally, the silicon oxide film 3 is formed by the hydrofluoric acid aqueous solution.
By removing 06, as shown in FIG. 3 (F), the AFM cantilever 3 including the supporting portion 307 made of glass, the cantilever portion 308 made of silicon, and the probe portion 309.
12 is obtained.

According to this embodiment, since a special substrate is not required as the starting substrate, the AFM cantilever according to the present invention can be manufactured at a lower cost.

[Third Embodiment] Next, the SPM according to the present invention
As a third embodiment of the manufacturing method of the cantilever, the same S
Regarding another manufacturing method using i as a cantilever member,
This will be described with reference to FIGS. In addition, also in FIGS. 4A to 4F, the members equivalent to or corresponding to the members shown in FIGS. 2A to 2F in the first embodiment have the 400s instead of the 200s. Corresponding reference numerals are attached. In this embodiment, the start board 4
00, as shown in FIG.
On the p-type silicon substrate 401 of (0), the plane orientation (1
00) in which n-type silicon layers are laminated. As a method of manufacturing the start substrate 400, the n-type impurity layer 4 which becomes the cantilever forming portion on the p-type silicon substrate 401 is used.
No. 03 is formed, or the n-type epitaxial layer 403 to be a cantilever forming portion is laminated on the p-type silicon substrate 401. Next, as shown in FIG. 4B, a replica hole 404 for forming a probe is formed so as to penetrate to the silicon substrate 401. Also in this embodiment, similarly to the second embodiment, the dry etching method and the wet etching method can be used for forming the replica hole.

In the same manner as in the first embodiment, FIG.
As shown in (C) to (E), the steps of depositing and etching the probe forming member 405, forming the cantilever pattern 411, forming the silicon oxide film 406, and joining the glass substrate to be the supporting portion 407 are performed.

Thereafter, the back surface of the start substrate 400 is removed by etching. At this time, a potential difference is applied between the p-type silicon substrate 401 and the n-type impurity layer or the n-type epitaxial layer 403 by a power supply 413. Meanwhile, the p-type silicon substrate 401 is removed by etching with an alkaline aqueous solution such as a potassium hydroxide aqueous solution. By adopting this method, when the p-type silicon substrate 401 is gradually etched and the n-type impurity layer or the n-type epitaxial layer 403 is exposed, a silicon oxide film is formed at the interface, so that the etching is automatically performed. Stop.
Finally, a silicon oxide film 4 is formed by using a hydrofluoric acid aqueous solution.
By removing 06, as shown in FIG. 4 (F), the SPM cantilever 4 including the support portion 407 made of glass, the cantilever portion 408 made of silicon, and the probe portion 409.
12 is obtained.

[Fourth Embodiment] Next, the SPM according to the present invention.
Similarly, as a fourth embodiment of the manufacturing method of the cantilever, S
Regarding another manufacturing method using i as a cantilever member,
A description will be given with reference to FIGS. 5 (A) to 5 (F), members equivalent to or corresponding to the members shown in FIGS. 2 (A) to 2 (F) in the first embodiment are not in the 200 range but in the 500 range. Corresponding reference numerals are attached. In this embodiment, the start board 5
00, as shown in FIG.
A silicon substrate 503 having a plane orientation (111), which is a cantilever forming member, is bonded to the p-type silicon substrate 501 of (0). Next, as shown in FIG. 5B, the replica hole 504 for forming the probe is formed in the silicon substrate 50.
It is formed so as to penetrate up to 1.

The following steps are exactly the same as in the first embodiment.
As shown in FIGS. 5C to 5F, the probe forming member 50
5, deposition and etching, cantilever pattern 511 formation, silicon oxide film 506 formation, glass support 5
After the steps of bonding 07 and removing the silicon substrate 501 by etching, an SPM cantilever 512 including a glass support portion 507, a silicon cantilever portion 508, and a probe portion 509 is obtained.

According to the manufacturing method shown in this embodiment, since the starting substrate 500 is the silicon substrate 501 having the plane orientation (100) and the silicon substrate 503 having the plane orientation (111) bonded to each other. When the underlying silicon substrate 501 is removed by etching, the etching can be surely stopped at the interface of the silicon substrate 503. This is because, for example, when an aqueous potassium hydroxide solution is used as an etching solution, the etching rate of the (111) plane is reduced to about 1/400 of that of the (100) plane.

[Fifth Embodiment] Next, the SPM according to the present invention
A fifth embodiment of the cantilever manufacturing method will be described with reference to FIGS. In addition, FIG. 6 (A)
Also in (F) to (F) of FIG.
2 to (F) are equivalent to or correspond to the members shown in (F).
Instead of the 00 series, the corresponding reference numerals of the 600 series are attached. In this embodiment, a cantilever forming member using a silicon nitride film will be described. First, as a start substrate 600, as shown in FIG. 6A, a silicon nitride film 603 which is a cantilever forming member is formed on a silicon substrate 601 having a plane orientation (100), and if necessary, a silicon oxide film 603 is further formed on the silicon nitride film 603. What formed the film 613 is used. Since this silicon nitride film 603 is a constituent member of the cantilever portion, the film composition thereof contains more silicon than the one having a content ratio of silicon to nitrogen of 3: 4. This is because after the base silicon substrate 601 is removed by etching, S
This is to reduce the difference in thermal expansion coefficient with i. On the other hand, the silicon oxide film 613 is formed by subjecting the start substrate 600 to oxidation treatment in a thermal oxidation furnace, or by depositing a silicon oxide film by a CVD method. The silicon oxide film 613 functions as an etching prevention layer for preventing the silicon nitride film 603, which is a cantilever member, from being simultaneously etched when the probe forming member is later removed by etching after deposition. . Therefore, it is not limited to the silicon oxide film.

Next, as shown in FIG. 6B, a replica hole 604 for forming a probe is formed so as to penetrate to the silicon substrate 601. Also in this embodiment, similarly to the second and third embodiments, the dry etching method and the wet etching method can be used for forming the replica hole. The deposition and etching of the probe forming member 605, as shown in FIGS. 6C to 6F, are performed by the same steps as those in the first embodiment.
Formation of cantilever beam pattern 611, glass support portion 60
After the steps of joining 7 and removing the silicon substrate 601,
Support part 607 made of glass and cantilever part 60 made of silicon
8 and SPM cantilever 612 including a probe 609.
Is obtained.

Since no special substrate is used in this embodiment, the SPM according to the present invention is very simple and inexpensive.
Cantilevers can be made. Further, it is difficult to manufacture a cantilever having a large cantilever thickness by the manufacturing method of this embodiment, but conversely, it becomes possible to construct a cantilever portion having a very thin thickness of, for example, about 200 nm. . Since an AFM cantilever composed of such a thin cantilever has a soft lever characteristic, by using such a cantilever in the AFM measurement by the contact method, the detection sensitivity is high and the resolution is excellent. Is possible.

[Sixth Embodiment] Next, the SPM according to the present invention will be described.
A sixth embodiment of the cantilever will be described with reference to the perspective view of FIG. The SPM cantilever 700 of the present embodiment is an SPM that is suitable for SNOM measurement.
A cantilever, which is a cantilever 701 made of a metal plate such as stainless steel, is provided with a hole 702 at the tip thereof.
In addition, an optical fiber portion 705 including a core 703 for guiding light and a clad 704 having a refractive index smaller than that of the core 703.
Is inserted, and a conical probe portion 706 is integrally formed at the tip of the core 703 of the optical fiber portion 705 by etching with a mixed solution of hydrofluoric acid and ammonium fluoride. The other end 703a of the core 703 is cut flat.

In the SPM cantilever 700 configured as described above, the evanescent light and scattered light incident from the probe portion 706 are transmitted through the core 703 while repeating total reflection at the interface of the clad 704 having a small refractive index. The photodetector (not shown) such as a photodetector arranged above the optical fiber portion 705 holding the probe portion 706 is irradiated from the end surface 703a of the core 703.

As described above, according to the SPM cantilever according to the present embodiment, the evanescent light incident from the tip of the probe portion and the scattered light scattered at the tip of the probe portion do not lose the light above the probe portion. Can illuminate the detector and therefore
The sensitivity can be improved when used for SNOM measurement. AFM measurement can also be performed by applying an optical probe of an optical displacement sensor to the cantilever portion 701. Therefore, by using the SPM cantilever of this embodiment, SNOM measurement and AFM measurement can be performed, and simultaneous measurement thereof can be performed. It can be carried out.

In this embodiment, the cantilever portion is formed of a metal plate such as stainless steel, but the cantilever portion has a plate shape capable of holding the optical fiber portion having the probe portion. Any materials can be used as long as they are Further, in the present embodiment, the optical fiber section 705
Although a hole 702 is provided at the tip of the cantilever 701 to hold it, as shown in FIG. 7B, the tip of the cantilever 701 is U-shaped or semicircular. A cutout portion 702a having a shape may be provided, and the cutout portion 702a may be configured to hold the optical fiber portion 705.

[Seventh Embodiment] Next, the SPM according to the present invention will be described.
A seventh embodiment of the cantilever will be described with reference to the sectional view of FIG. SPM cantilever 710 in this example
Is configured by providing a probe portion 714 whose periphery is covered with a probe receiver 713 at the tip of a cantilever portion 712 extending from the support portion 711. The probe portion 714 has a hollow conical shape with a substantially uniform film thickness and a hollowed inside. The probe portion 714 is not limited to this shape and may be a hollow pyramid shape such as a pyramid. Then, the refractive index of the material of the probe portion 714 is n ₁ , and the probe receiver 7
It is set such that n ₁ > n ₂ when the refractive index of the material of _No. 13 is n ₂ . The probe portion 714 covered with the probe receiver 713 is a cutout portion or the like provided at the tip of the cantilever portion 712 as in the modification of the sixth embodiment shown in FIG. 7B. Is held.

The transmission of light in materials having different refractive indices is
As the refractive index of the probe receiver 713 is set to be lower than the refractive index of the probe portion 714, the light is collected within a certain angle from the tip of the probe portion 714. The light incident at an angle receives the probe 714 and the probe receiver 71.
The light is repeatedly reflected at the interface of No. 3 and is not emitted to the outside of the probe portion 714, or the emitted light amount is minimized and transmitted to the upper portion of the probe portion 714.

As described above, according to the SPM cantilever of the present embodiment, the evanescent light incident from the tip of the probe portion 714 and the scattered light scattered at the tip of the probe portion 714 are held by the probe receiver 713 and the cantilever. It is possible to irradiate the photodetector above the probe portion without propagating to the beam portion 712. Therefore, the loss of evanescent light and scattered light can be prevented, and the sensitivity can be improved when used for SNOM measurement. Further, similar to the sixth embodiment, the AFM measurement can be performed by applying the optical probe of the optical displacement sensor to the cantilever portion. Therefore, the SNOM measurement and the AFM measurement can be performed by using the SPM cantilever of the present embodiment. Yes, they can be measured simultaneously.

Incidentally, in this embodiment, the cantilever portion 71
As the forming material of 2, a silicon nitride film or a silicon oxide film which is generally used as an SPM cantilever material can be used, but the forming material is not particularly limited.

[Eighth Embodiment] Next, the SPM according to the present invention
An eighth embodiment of the cantilever will be described with reference to the sectional view of FIG. The SPM cantilever 720 in this embodiment includes a cantilever portion 72 extending from the support portion 721.
A probe portion 724, the periphery of which is covered with a probe holder 723 made of metal, is provided at the tip of the second probe 2. The probe portion 724 has the same configuration as that of the seventh embodiment shown in FIG. 8, and the material for forming the cantilever portion 722 is not particularly limited in this embodiment.

The SPM cantilever 7 having the above structure
20, the light entering from the tip of the probe portion 724 is repeatedly reflected at the interface between the probe portion 724 and the probe receiver 723,
It is not emitted to the outside of the probe portion 724, or is transmitted to the upper portion of the probe portion 724 with the amount of emitted light being minimized. Therefore, as in the sixth embodiment, the evanescent light incident from the tip of the probe 724 and the scattered light scattered at the tip of the probe 724 do not propagate to the probe receiver 723 or the cantilever 722. It is possible to irradiate the photodetector above the probe portion, and therefore, it is possible to improve the sensitivity when used for SNOM measurement. Further, similarly to the sixth embodiment, by applying an optical probe of an optical displacement sensor to the cantilever portion, SNOM measurement and AFM measurement can be performed, and simultaneous measurement of them can also be performed.

Further, as shown in FIG. 9B, by providing the metallic probe receiver 723a so as to cover the probe portion 724 to the vicinity of the tip, incident light from other than the surface of the measurement sample. SNO with higher resolution
M measurements can be made.

[Ninth Embodiment] Next, the SPM according to the present invention will be described.
A ninth embodiment of the cantilever will be described with reference to the sectional view of FIG. SPM cantilever 730 in this example
Is constituted by providing a tip portion of a cantilever portion 732 extending from the support portion 731 with a probe portion 734 made of a bulk homogeneous isotropic medium, the periphery of which is covered with a probe receiver 733. There is. The probe receiver 733 is made of a material having a lower refractive index than the probe portion 734. Therefore, light incident at an incident angle within a certain angle from the tip of the probe portion 734 is repeatedly reflected at the interface between the probe portion 734 and the probe receiver 733 and is not emitted to the outside of the probe portion 734. , Or the amount of emitted light to a minimum,
4 is transmitted. Also in this embodiment, the material for forming the cantilever beam 732 is not particularly limited. Further, in the present embodiment, the probe portion 734 is formed of the bulky homogeneous isotropic medium for the following reason. That is, in the probe portions 714 and 724 of the seventh and eighth embodiments shown in FIGS. 8 and 9 and having a hollow cone or pyramid shape with a substantially uniform film thickness and hollowed inside, the probe portions are The scattered light that has entered from the outer tips of 714 and 724 is scattered again by the inner tip portions 714a and 724a of the hollow probe portion, and the amount of light transmitted above the probe portions 714 and 724 is attenuated. In this embodiment, since the bulky homogeneous isotropic medium is used, such a phenomenon can be prevented.

As described above, according to the SPM cantilever of the present embodiment, as in the sixth embodiment, the evanescent light incident from the tip of the probe portion and the scattered light scattered at the tip of the probe portion are detected. It can irradiate the photodetector above the probe without propagating to the needle receiver or cantilever, thus preventing the loss of evanescent light or scattered light and improving the sensitivity when used for SNOM measurement. You can Also, SPM
By providing the SNOM measurement function in the probe portion of the cantilever, SNOM measurement and AFM measurement can be performed, and simultaneous measurement can be performed.

[Tenth Embodiment] Next, a tenth embodiment will be described with reference to FIG.
This will be described with reference to the sectional view of FIG. SP in this embodiment
The M cantilever 740 includes a probe portion 744 made of a bulk homogeneous isotropic medium, the periphery of which is covered with a probe receiver 743 made of metal at the tip of a cantilever portion 742 extending from the support portion 741. Is provided. Similarly, the material for forming the cantilever portion 742 is not particularly limited.

The SPM cantilever 7 constructed in this way
In 40, the light incident from the tip of the probe 744 is repeatedly reflected at the interface between the probe 744 and the probe receiver 743, and is not emitted to the outside of the probe 744 or is emitted. Minimize the amount of light and use the probe 74
4 is transmitted. Therefore, similarly to the sixth embodiment, the evanescent light incident from the tip of the probe portion and the scattered light scattered at the tip of the probe portion do not propagate to the probe receiver or the cantilever portion, and Can illuminate the upper photodetector,
It is possible to prevent loss of evanescent light and scattered light and improve sensitivity when used for SNOM measurement.
Further, by providing the probe portion of the SPM cantilever with a function for SNOM measurement, SNOM measurement and AFM measurement can be performed, and simultaneous measurement thereof can also be performed.

Further, as in the modified example of the eighth embodiment shown in FIG. 9B, the metallic probe receiver 743 is connected to the probe portion 7.
By providing so as to cover the vicinity of the tip of 44, it is possible to prevent the incidence of light from other than the surface of the measurement sample,
Higher resolution SNOM measurements can be performed.

The seventh to tenth parts shown in FIGS.
In the embodiment, the one in which the probe portion is held by the notch provided at the tip of the cantilever portion is shown, but the holding of the probe portion is not limited to such a mode, Figure 7
As in the sixth embodiment shown in (A) above, the probe portion may be inserted and held in the hole provided at the tip of the cantilever portion.

[Eleventh Embodiment] The SP according to the present invention
An eleventh embodiment of the M cantilever will be described together with a manufacturing method based on the manufacturing process diagrams shown in FIGS. 12 and 13.
First, as shown in FIG. 12A, the silicon wafer 8
No. 01 is prepared, and as shown in FIG. 12B, a replica hole 80 for a probe is formed on a silicon wafer 801 by photolithography and wet etching or dry etching.
Form 2. Then, as shown in FIG.
A silicon nitride film 803 having a film thickness of 0.4 to 1 μm is formed on the silicon wafer 801 by the CVD method. Next, as shown in FIG. 12D, a silicon oxide film 804 is formed over the silicon nitride film 803 by a CVD method or the like, and photolithography and wet etching or dry etching are performed.
The silicon oxide film 804 and the silicon nitride film 803 in the replica hole 802 are removed. Then, in FIG.
As shown in, the silicon nitride film is formed again and patterned into the shape of the probe portion 805.

Subsequently, as shown in FIG. 13A, the silicon oxide film 804 is patterned into the shape of the probe receiver 806, and finally the silicon nitride film 803 is cantilevered.
7 is patterned. On the other hand, as shown in FIG. 13 (B), the Pyrex glass 810 serving as the supporting portion.
Is processed according to the shape pattern of the cantilever portion 807 on the silicon wafer 801, and as shown in FIG. 13C, the end portion of the cantilever portion 807 on the silicon wafer 801 and the supporting portion 811 are formed. Is anodically bonded. Finally, as shown in FIG. 13D, the silicon wafer 801 is removed by etching with a 40% KOH aqueous solution.
The PM cantilever 812 is completed.

The SPM cantilever 812 manufactured in this manner has a cantilever portion 807 made of a silicon nitride film extending from a glass support portion 811 and a probe receiver 806 made of a silicon oxide film interposed therebetween. The probe unit 805 is held by the structure. In this way, the probe portion 805 and the cantilever portion 807 form the probe receiver 8
However, the probe portion 805 and the cantilever portion 807 are not in direct contact with each other.

In the SPM cantilever configured as described above, since the probe portion 805 is formed of the silicon nitride film, its refractive index is 2.1 to 2.2, while the probe receiver 806 is Since it is made of a silicon oxide film,
Its refractive index is 1.4 to 1.5. Therefore, the probe unit 8
Since the probe receiver 806 has a lower refractive index than that of the probe No. 05, light incident from the tip of the probe unit 805 does not propagate to the probe receiver 806, and thus the cantilever beam unit 807. in this way,
The light incident from the probe portion 805 is prevented from propagating into the cantilever portion 807 by the probe receiver 806 made of a silicon oxide film, so that the light disposed above the probe portion 805 with a small loss. The detector can be illuminated. Therefore, when used for SNOM measurement, loss of evanescent light and scattered light can be prevented, and thus sensitivity can be improved. In addition, by using the above manufacturing process,
The SPM cantilever can be manufactured easily and stably.

[0070]

As described above on the basis of the embodiments,
In the SPM cantilever according to the present invention, since the cantilever and the probe part are formed by separate members, it is possible to satisfy both the required characteristics as the cantilever and the required characteristic as the probe part. Further, since the cantilever support portion is configured to be bonded to the surface of the cantilever, it can be easily manufactured by processing only from the surface of the substrate. Further, by using a light transmissive member for the probe part, SNOM measurement, by using a conductive member for STM, by using a transparent conductive member, SNOM and STM by using a hard member, mechanical processing Therefore, the SPM cantilever applicable to a very wide range of applications can be realized. Furthermore, by interposing an optical shielding part between the probe part composed of a light-transmissive member and the cantilever part, the incident light or scattered light from the probe part is transmitted to the upper part of the probe part without loss. It is possible to improve the S / N ratio when used for SNOM measurement, perform high-sensitivity and high-resolution SNOM measurement, and perform SNOM measurement and AFM measurement simultaneously. Further, according to the manufacturing method of the present invention, the SPM cantilever having the above structure can be easily manufactured only by processing from the surface of the substrate without requiring a special manufacturing apparatus.

[Brief description of drawings]

FIG. 1 is a perspective view and a cross-sectional view showing a first embodiment of an SPM cantilever according to the present invention.

FIG. 2 is a diagram showing a manufacturing process for explaining a manufacturing method of the SPM cantilever of the first embodiment shown in FIG.

FIG. 3 is a diagram showing a manufacturing process for explaining the second embodiment of the method for manufacturing an SPM cantilever according to the present invention.

FIG. 4 is a diagram showing a manufacturing process for explaining a third embodiment of the method for manufacturing an SPM cantilever according to the present invention.

FIG. 5 is a diagram showing a manufacturing process for explaining the fourth embodiment of the method for manufacturing an SPM cantilever according to the present invention.

FIG. 6 is a diagram showing a manufacturing process for explaining a fifth embodiment of the method for manufacturing an SPM cantilever according to the present invention.

FIG. 7 is a sectional view showing an SPM cantilever according to a sixth embodiment of the present invention and a modification thereof.

FIG. 8 is a sectional view showing an SPM cantilever according to a seventh embodiment of the present invention.

FIG. 9 is a sectional view showing an SPM cantilever according to an eighth embodiment of the present invention and a modification thereof.

FIG. 10 is a sectional view showing an SPM cantilever according to a ninth embodiment of the present invention.

FIG. 11 is a sectional view showing an SPM cantilever according to a tenth embodiment of the present invention.

FIG. 12 is a manufacturing process diagram illustrating a method for manufacturing an SPM cantilever according to an eleventh embodiment of the present invention.

FIG. 13 is a diagram showing a manufacturing process that follows the manufacturing process shown in FIG. 12.

FIG. 14 is a manufacturing process diagram for describing a conventional method for manufacturing an AFM cantilever.

[Explanation of symbols]

100 SPM cantilever 101 Cantilever part 102 Probe part 103 Support part 200, 300, 400, 500, 600 Start substrate 201 Silicon wafer 301 n-type silicon wafer 401 p-type silicon substrate 501 Silicon substrate 601 with plane orientation (601) Silicon Substrate 202 Silicon oxide film 203 Silicon wafer 303 p-type impurity diffusion layer 403 n-type impurity layer or n-type epitaxial layer 503 Silicon substrate with plane orientation (111) 603 Silicon nitride film 204, 304, 404, 504, 604 Replica hole 205, 305, 405, 505, 605 Probe forming member 206, 306, 406, 506, 606 Silicon oxide film 207, 307, 407, 507, 607 Support portion 208, 308, 408, 508, 608 Cantilever Parts 209, 309, 409, 509, 609 Probe parts 211, 311, 411, 511, 611 Cantilever beam patterns 212, 312, 412, 512, 612 SPM cantilever 613 Silicon oxide film 700, 710, 720, 730, 740 SPM cantilever 701 cantilever 702 hole 703 core 704 clad 705 optical fiber 706 probe 711, 721, 731, 741 support 712, 722, 732 742 cantilever 713 723 733 733 743 probe receiver 714, 724, 734 , 744 Probe part 801 Silicon wafer 802 Replica hole 803 Silicon nitride film 804 Silicon oxide film 805 Probe part 806 Probe receiver 807 Cantilever part 811 Support part 812 SPM cantilever

Claims (11)

[Claims] 1. A support portion of a cantilever, a cantilever arranged to extend from the support, a free end of the cantilever, and the support portion with respect to the cantilever. An SPM cantilever, comprising: a probe portion provided on the opposite side, that is, the support portion, the cantilever, and the probe portion, which are separate members. 2. The support portion of the cantilever is configured by a member joined to a surface of the cantilever opposite to the probe portion with respect to the cantilever. Of S
PM cantilever. 3. The SPM cantilever according to claim 1, wherein the probe portion is formed of a member transparent to visible light. 4. The SPM cantilever according to claim 1, wherein the probe portion is made of a conductive member. 5. The SPM according to claim 1, wherein the probe portion is made of a transparent conductive member.
Cantilever. 6. The SPM cantilever according to claim 1, wherein the probe portion is made of a hard member. 7. The probe part is made of a member transparent to visible light, and the probe part is held by a cantilever beam via an optical shield part. The SPM cantilever according to 1 or 2. 8. The SPM cantilever according to claim 7, wherein a refractive index of the probe portion is set to be larger than a refractive index of the optical shield portion. 9. The SPM cantilever according to claim 7, wherein the optical shield is made of a metal material. 10. The probe portion is formed of silicon nitride,
8. The SPM cantilever according to claim 7, wherein the optical shield part is formed of a silicon oxide film. 11. A step of forming a replica hole for a probe portion on a surface of a substrate by an etching process, a step of depositing a base material of the probe portion on a substrate including the replica hole, and a step of depositing the base material in a predetermined manner. A step of etching into a shape, a step of forming a cantilever beam pattern on the substrate surface, a step of joining a cantilever support member to one end surface of the cantilever beam pattern formed on the substrate surface, the substrate A method of manufacturing an SPM cantilever, comprising the step of etching and removing the back surface of the substrate, leaving a cantilever beam pattern formed on the surface by the thickness of the cantilever.