JPH11337561A - Cantilever for scanning type probe microscope and its holding mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide such a cantilever that the contact between a support part of the cantilever and a measurement sample can be easily avoided, and its holding mechanism. SOLUTION: The cantilever 142 has a first support part 118 formed integrally with a lever part 140, and a second support part 136 having a parallelepiped shape and supporting the first support part 118. A cantilever holding mechanism 170 has a holder body 172 on which a groove 174, having a shape corresponding to the second support part 136 of the cantilever 142, is formed, and a plate spring 176 fixed on the holder body 172 as it extends over the groove 174. Concerning the cantilever holding mechanism 170, the second support part 136 of the cantilever 142 is inserted into the groove 174 formed on the holder body 172, and the plate springs 176, installed on the side of the holder body 172, contacts with the first support part 118 of the cantilever 142, and pushes down the second support part 136 on the bottom face of the groove 174, to thereby hold the cantilever 142.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a mechanism for holding a cantilever used in a scanning probe microscope.

[0002]

2. Description of the Related Art A scanning probe microscope (SPM) has an interaction (for example, an interaction between a probe or a probe portion and a probe portion when the probe or probe portion comes close to or less than 1 μm or less).
This is a device that performs three-dimensional mapping of the interaction by scanning the probe part or the sample in the XY direction or the XYZ direction while detecting the atomic force, contact force, etc., and uses a scanning tunneling microscope (STM). , An atomic force microscope (AFM), a magnetic force microscope (MFM), a scanning near-field light microscope (SNOM), and the like. Above all, AFM
Is the most widespread among SPMs as a device for obtaining unevenness information on a sample surface.

In the AFM, a cantilever having a sharp protruding portion (a probe portion having a sharp tip) at the free end of a cantilevered lever portion is brought close to the sample so as to face the sample. Forces acting on atoms on the surface of the surface
The probe or cantilever is moved in the X and Y directions while measuring the amount of deflection of the probe and the amount of elastic deformation (deflection) of the lever part, which are displaced due to (atomic force, contact force, etc.). By scanning and relatively changing the positional relationship between the probe portion of the cantilever and the sample, it is possible to three-dimensionally capture information on the unevenness of the sample.

[0004] For example, an example of a method for detecting the amount of elastic deformation (bending) of a lever portion in SPM is disclosed in Japanese Unexamined Patent Publication No.
This is disclosed in JP-A-340718 and JP-A-9-15250. The detection of the amount of deflection of the lever portion disclosed in these publications is performed by using a known “optical lever type displacement detection sensor”. In addition, regarding the detection of the amount of deflection of the lever portion, a “defocus detection method using a critical angle prism”, a “displacement detection sensor using an optical interferometer”, and the like are known.

[0005] SPM measurement using this displacement detection sensor is performed as follows. The probe section X
Scanning is performed in the Y direction, and the amount of deflection of the lever portion in this measurement area is detected as needed by the above-described displacement detection sensor. The detected amount of deflection is imaged at atomic-level resolution as sample information such as surface unevenness of the sample and magnetic force, and displayed on a monitor (not shown).

[0006] The cantilever used for such an SPM is described in "Ato Ato" by Thomas R. Albrecht and Calvin F. Quate.
mic Resolution Imaging of a Nonconductor by Atomic
Force Microscopy "(J. Appl. Pys. 62 (1987) 2599)
As described in (1), since the SiO ₂ cantilever manufactured by applying the semiconductor IC manufacturing process was proposed, it can be manufactured with high accuracy on the order of microns and with high reproducibility, and the cost can be reduced by using a batch process. For the reason that they are excellent in terms of quality, those manufactured by applying this IC manufacturing process are mainly used.

At present, there are two types of cantilevers commercially available, a cantilever made of silicon nitride and a cantilever made of silicon. Silicon nitride cantilevers are described in Tomas R. Albrecht et al.'S "Microfabrication of
cantilever styli for the atomic force microscope ''
(J. Vac. Sci. Technol. A8, 3386 (1990)) is the mainstream, and a detailed production method is described in US Pat. No. 5,399,232. Also, silicon cantilevers are available from O. Wolter et al.
silicon sensors for scanning force microscopy '' (J.
The cantilever described in Vac. Sci. Technol. B9, 1353 (1991)) is the mainstream, and a detailed production method is described in US Pat. No. 5,051,379.

[0008]

In the cantilever manufactured in this manner, the support for supporting the lever has a contact surface parallel to the surface of the lever. The cantilever is fixed to the device by applying this contact surface to the SPM device and holding it down using a fixture such as a spring.

[0009] The fixture for holding down the support portion of the cantilever is as follows.
It is located below the device, corresponding to the shape of the cantilever. In order to avoid contact between the fixture and the measurement sample, the cantilever is mounted such that the surface of the lever portion is oblique to the surface of the measurement sample.

However, the space margin obtained by mounting the cantilever obliquely is small, and this does not completely avoid the contact between the fixture and the measurement sample. Further, as the size of the cantilever is reduced, since the space margin is reduced by attaching the cantilever obliquely, it becomes more difficult to avoid contact between the fixture and the measurement sample.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cantilever capable of easily avoiding contact between a support portion of the cantilever and a measurement sample, and a mechanism for holding the cantilever. That is.

[0012]

A cantilever for a scanning probe microscope according to the present invention has a plate-like lever portion that can be elastically deformed, and a support portion that supports the lever portion in a cantilever manner. Has a surface that is applied to the holding mechanism,
This contact surface is perpendicular to the surface of the lever portion.

The cantilever holding mechanism according to the present invention comprises a holder body having a groove formed in a shape corresponding to the support portion of the cantilever, and a leaf spring fixed to the holder body so as to extend above the groove. Have.

Another cantilever holding mechanism according to the present invention comprises a holder main body having a groove formed in a shape corresponding to the cantilever support, and a cantilever support through a suction hole formed in the bottom surface of the groove. And a suction device for sucking the air.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 10 schematically show a method of manufacturing a cantilever for a scanning probe microscope (SPM) of the present invention.

First, as shown in FIG. 1, a so-called bonded SOI (Silicon On Insulator) substrate 108 is prepared. This bonded SOI substrate 108 has a plane orientation (10
0) First silicon substrate 10 made of single crystal silicon
After forming the intermediate silicon oxide film 104 on the surface of No. 2, a second silicon substrate 106 made of single crystal silicon having a plane orientation of (100) to be an active layer is bonded. For example, the thickness of the first silicon substrate 102 is 500 μm,
The thickness of the intermediate silicon oxide film 104 is 1 μm, and the thickness of the second silicon substrate 106 is 20 μm.

Next, as shown in FIG. 2, an etching mask 110 for forming a second support portion, which will be described later, is formed on the back surface of the first silicon substrate 102 by patterning a silicon oxide film or a silicon nitride film. Formed. On the other hand, an etching mask 112 for determining the width of the lever portion is similarly formed on the surface of the second silicon substrate 106 by patterning a silicon oxide film or a silicon nitride film.

As shown in FIG. 3, the second silicon substrate 1
06 is subjected to wet anisotropic etching to determine the thickness of a portion 114 where a lever portion will be formed later. The thickness of the portion 114 forming the lever portion is the width of the lever portion, and is set here to 5 μm.

When the design value of the width of the lever portion of the cantilever is substantially equal to the thickness of the second silicon substrate 106 of the bonded SOI substrate 108, the steps shown in FIGS. 2 and 3 can be omitted.

As shown in FIG. 4, the second silicon substrate 1 is formed by photolithography and dry etching.
After a silicon nitride film 116 is formed on the surface of the substrate 06 and patterned, a second silicon substrate is
The (active layer) 106 is selectively removed until the intermediate silicon oxide film 104 of the SOI substrate 108 is exposed, and the first support portion 118 and the lever base portion 1 which is a base of the lever portion are removed.
20 and a probe forming portion 122 which is a base of the probe portion.

The width (lateral dimension) of the lever base 120 is determined by photolithography pattern formation.
Etching was performed with a width of m. Also, the lever base 120
The length is determined by considering the shape of the lever portion to be formed later.
μm. Also, the etching surface 1 of the probe forming portion 122
24 are formed slightly inclined from the <110> direction. Also,
The inclination of the etching surface 126 of the probe forming portion 122 from the <110> direction determines the height of the probe portion (in other words, the aspect ratio). For example, when the probe portion having a height of 10 μm is formed. Is selected to be about 70 °.

Next, as shown in FIG.
After a wall 128 of a silicon oxide film is formed by a heat diffusion furnace on the side end surface of the second silicon substrate 106 on which the 18, the base portion 120 and the probe forming portion 122 are formed, The silicon nitride film 116 on the surface is removed to expose the silicon 106.

As shown in FIG. 6, the second silicon substrate 106 of the probe forming portion 122 is subjected to wet anisotropic etching until the intermediate silicon oxide film 104 is exposed, so that the second silicon substrate 106 has a shape close to the probe portion of the cantilever. Triangular pyramid shaped probe base 1
Form 30. In this wet anisotropic etching, a potassium hydroxide aqueous solution (KOH) having a predetermined concentration, tetramethylammonium hydroxide (TMAH), ethylenediamine pyrocatechol and water (EDP) are used.
Or called EPW).

In the wet anisotropic etching of single crystal silicon such as the second silicon substrate, the (111) plane is more difficult to be etched than the (100) plane of the silicon substrate. By the etching process, single-crystal silicon is etched from the end of the silicon nitride film 116 remaining in the lever base 120 so that the (111) plane is exposed. The remaining single-crystal silicon of the probe base portion 130 is exposed to the exposed (111) plane and the intermediate silicon oxide film 1.
It has a triangular pyramid shape having three side surfaces of the (100) plane 04 and the silicon oxide film wall 128 on the etching surface 126 side. The probe base 130 becomes a probe after an oxidation step.

Next, as shown in FIG. 7, a silicon oxide film 132 is formed on the surfaces of the probe base 130 and the lever base 120 having a triangular pyramid shape by a thermal diffusion furnace (thermal oxidation). In FIG. 7, the silicon oxide film 132 is formed by removing the silicon oxide wall 128 in the previous step, but the silicon oxide film 132 is not removed without removing the silicon oxide wall 128.
May be formed.

As shown in FIG. 8, the second silicon substrate 1
A part of the 06-side intermediate silicon oxide film 104 is removed,
An etching pattern for forming a second support portion described later is formed.

Subsequently, as shown in FIG. 9, the first silicon substrate 102 is subjected to wet anisotropic etching from the front and back surfaces to form a second support portion 136.

Finally, as shown in FIG. 10, the first support portion 118 is heated with an aqueous solution of hot phosphoric acid or an aqueous solution of hydrogen fluoride.
By removing the silicon oxide film and the silicon nitride film except for the intermediate silicon oxide film 104 sandwiched between the second support portion 136 and the second support portion 136, the cantilever 142 as a finished product is obtained.

The cantilever 142 has, for example, a thickness of the lever portion 140 of 0.4 μm, a length of 20 μm, a width of 5 μm, a height of the probe portion of about 10 μm, and a resonance frequency of 1.4 MHz. , And the spring constant is 1.7 N / m.

In the above-described manufacturing method, as shown in FIG. 10, the cantilever 142 in which the second support portion 136 is located on the left side with respect to the extending direction of the lever portion 140 is manufactured. By changing the patterning shape of the silicon nitride film 116 in the step of FIG. 11, as shown in FIG.
A cantilever in which 36 is located can also be made.

At present, attempts have been made actively to perform high-speed scanning such as one or more raster scans per second to observe a micro operation of a biological sample or the like. A cantilever suitable for such high-speed scanning can be provided.

Here, a cantilever suitable for high-speed scanning has a resonance frequency of the order of MHz and a spring constant of 40 to 40 to prevent breakage of the measurement sample and the probe caused by contact with the probe.
It refers to those of 50 N / m or less. In a cantilever satisfying this condition, for example, the length of the lever portion is 40 μm or less,
The thickness becomes 1 μm or less.

Conventionally, the length and thickness of the lever portion could not be manufactured stably as described above, but the manufacturing method according to the present embodiment can stably control the length and thickness of the lever portion. Therefore, such a cantilever can be easily provided.

One feature of the above embodiment is that a semiconductor substrate is selectively removed by using a semiconductor process to produce a cantilever comprising a probe portion, a lever portion, and a support portion. The feature is that the cantilever is manufactured by etching the semiconductor substrate in the width direction of the plate-shaped lever portion of the cantilever to be manufactured.

As shown in FIG. 10, the cantilever 142 manufactured by the manufacturing method of this embodiment has a strip-shaped single crystal silicon lever 140, and a substantially triangular pyramid is formed at a free end of the lever 140. A shaped probe 138 is formed. The lever portion 140 is supported by a first support portion 118, and the first support portion 118 is provided on the intermediate silicon oxide film 104.
And is supported by the second support portion 136 via the.

The lever 140 and the first support 118 are
The second silicon substrate 106 is integrally formed by performing a semiconductor process. For this reason, the length of the lever portion 140 is different from that of the wet etching in the process of FIG.
Is determined by the photolithography of the step and the oxidation of the step of FIG. Therefore, the variation in the length of the lever portion 140 is as follows.
It can be suppressed to 1 μm or less, and 100 nm or less under appropriate conditions. As a result, the lever portion 140 can be manufactured with a length of, for example, 10 μm and a variation of 10% or less.

The thickness of the lever portion 140 is determined by the photolithography in the step of FIG. 4, the oxidation in the step of FIG. 5, and the oxidation in the step of FIG. That is, the thickness of the lever 140 is controlled by these three steps.

First, as shown in FIG. 12A, the initial thickness T0 of the lever base 120 is determined by the photolithography and dry etching steps of FIG. The thickness T0 of the lever base 120 is, for example, 2 μm.
m.

Next, as shown in FIG. 12B, the step of oxidizing the silicon shown in FIG.
Is partially oxidized into silicon oxide, whereby a wall 128 of a silicon oxide film is formed. As a result, the thickness of the lever base 120 decreases from T0 to T1. The thickness T1 of the lever base 120 is, for example, 1.2 μm.

Finally, as shown in FIG. 12 (c), the step of oxidizing the silicon shown in FIG.
A portion of the remaining 0 is oxidized to form a silicon oxide film 132. As a result, the thickness of the lever base 120 decreases from T1 to T2. The lever base part 120 remaining after this step becomes the lever part 140 through a subsequent step of removing the silicon oxide film. That is, the lever portion 140 having the thickness T2 is formed.
The thickness T2 of the lever portion 140 is, for example, 0.4 μm.

As described above, the lever base 120 is processed to a thickness of about 2 μm (horizontal dimension) with high dimensional accuracy by photolithography and dry etching, and is oxidized from the lateral direction to form the lever base 120. Since the final thickness of 140 is determined and the progress of oxidation can be controlled with high precision, the lever portion 140 is set to a desired thickness, for example, 0.1 mm.
It can be formed with a precision of 4 μm. in this way,
The variation in the thickness of the lever portion 140 depends on the patterning accuracy of photolithography and the controllability of silicon oxidation, and can be suppressed to 100 nm or less and 10 nm or less under appropriate conditions.

The dry etching used to form the lever base 120 mainly uses RIE (Rea
ctive Ion Etching), particularly RIE using highly anisotropic plasma conditions and introduced gas, and ICP-type RIE (Ind
Suitable is uctively coupled plasma, which is effective for controlling the cross-sectional shape of the lever 140.

The lever base 120 formed to a predetermined thickness by photolithography and dry etching.
Is oxidized from the lateral direction and the formed silicon oxide is removed to form the lever portion 140, so that a cantilever having a lever portion thinner than the resolution limit of photolithography can be manufactured.

As described above, according to the manufacturing method described above,
The lever portion 140 can be stably manufactured in a desired shape with high dimensional accuracy. Therefore, it is possible to provide an SPM cantilever having a resonance frequency and a spring constant suitable for various SPM measurement methods.

In particular, according to the above-described manufacturing method, a cantilever 142 having a short and thin lever portion 140 can be manufactured, and such a cantilever is used when observing a time change of a measurement sample or the like. It is suitable for SPM measurement that performs high-speed scanning.

In the cantilever 142 manufactured by the manufacturing method of the present embodiment, as shown in FIG. 15, the probe 138 has a triangular pyramid-shaped tip, and three tips defining the tip are provided. Two of the faces are silicon (111)
The surface and the (100) surface, and the remaining surface 144 on the support portion side is formed by artificial processing. Therefore, the radius of curvature of the tip of the probe part 138 is caused by the step of forming the surface 144 on the support part side. This surface 144 is defined by the etching surface 126 of the probe forming part 122 formed in the step of FIG.

As shown in FIG. 13, the etching surface 126 of the probe forming portion 122 formed in the step of FIG. 4 is a flat surface formed by photolithography and dry etching. Therefore, the roughness of the etching surface 126 generated by the dry etching determines the radius of curvature of the tip of the probe 138.

Generally, surface roughness due to dry etching is 1
Since it is 0 nm or less, as shown in FIG. 14, when the (111) plane of silicon is exposed to form the probe base 130, the radius of curvature of the tip of the probe base 130 is already It is 10 nm or less. Therefore, the radius of curvature of the probe 138 formed through the subsequent oxidation step is stably sharpened to 10 nm or less.

As shown in FIG. 13, the aspect ratio of the probe portion 138 is such that the probe forming portion 122 has a surface including <110> (which is parallel to the surface of the lever portion 140 to be formed later). Is determined by the inclination θ of the etching surface 126.
The inclination θ of the etching surface 126 is a design parameter that can be arbitrarily selected by the maker of the cantilever.

Therefore, in the above-described embodiment, θ = 7
Although the probe portion 138 having an apex angle of 20 ° is formed by selecting 0 °, a probe portion having a higher aspect ratio can be formed by selecting an even larger value for θ.

Further, in the step of FIG. 7, the probe base portion 130 is oxidized by a heat diffusion furnace or the like, which oxidizes the probe base portion 130. The temperature at this time is 900 to 1000 ° C., preferably 95
By setting the temperature to 0 ° C., which is lower than the temperature at which a silicon oxide film is formed by a normal semiconductor process, a sharper probe portion 138 can be formed (low-temperature thermal oxidation). This is because the growth speed of the silicon oxide film is increased by the probe portion 138.
As a result, the silicon portion that is not oxidized, that is, the portion that eventually becomes the probe portion, is sharpened toward the tip, and the radius of curvature of the tip becomes several nm or less.

In the cantilever 142, the probe 13
The distal end of the lever 8 is located substantially at the free end side of the lever 140, which is offset from the central axis of the lever 140. Therefore, it is possible to perform SPM measurement on a sample having a steep step up to the last step.

In addition, since the tip of the probe portion 138 is located almost directly below the vertex on the free end side of the lever portion 140, the position can be adjusted based on the vertex on the free end side of the lever portion 140 as a reference. In addition, the tip of the probe 138 can be indirectly positioned. For example, in many SPM devices in which the position of the lever portion and the measurement sample can be aligned using an optical microscope, the tip of the probe portion is adjusted by aligning the vertex of the lever portion with the position on the measurement sample where the SPM measurement is to be performed. It is arranged above the place on the measurement sample where the SPM measurement is desired. Therefore, when the SPM measurement is performed using the cantilever 142, the alignment between the probe portion and the sample becomes easy.

As described above, the tip of the probe portion 138 is defined by the (111) surface and the (100) surface of silicon and the surface 144 that can be processed artificially. 122 is defined by the etched surface 126. In addition, the shape of the etching surface 126 can be arbitrarily selected. Therefore, by changing the shape of the etching surface 126, it is possible to produce a probe having a different shape from the probe 138 shown in FIG.

Hereinafter, a modified example of the etched surface and a probe formed based on the etched surface of the modified example will be described.

In the first modification, as shown in FIG.
The etching surface 126 ′ of the probe forming part 122 is <110>
A plane 126a having an inclination θ with respect to a plane including
Plane 126b having an inclination φ (> θ) with respect to the plane including 0>
It is composed of

When the above-described manufacturing method is similarly applied to the etching surface 126 'having such a shape, FIG.
As shown in FIG. 5, a silicon oxide wall 128 ′ bent in the middle reflecting the shape of the etching surface 126 ′ is formed,
The probe base portion 130 'has a shape in which a tip portion has a truncated triangular pyramid and a triangular pyramid having a higher aspect ratio than the truncated pyramid.

As a result, as shown in FIG. 18, a probe portion 138 'having a tip portion having a shape in which a triangular pyramid having an aspect ratio higher than that of the truncated triangular pyramid is continuous is obtained. The tip of the probe 138 ′ has a (111) plane of silicon and (10
0) is defined by a plane and a plane 144 ′, and the plane 144 ′ reflects the shape of the etching surface 126 ′ of the probe forming unit 122 and has a plane 144 having an inclination θ with respect to the plane including <110>.
a and a plane 144b having an inclination φ (> θ) with respect to the plane including <110>.

The probe portion 138 'having this shape can realize an improvement in the aspect ratio of the tip and an increase in the height without substantially reducing the overall rigidity and strength.

In the simple triangular pyramid-shaped probe portion 138 as shown in FIG. 15, if the value of the inclination θ is increased to improve the aspect ratio or height of the tip, it is inevitable. The rigidity and strength of the entire probe are reduced. Therefore, the upper limit of the aspect ratio and height of the tip of the probe 138 is determined by the purpose of use of the probe and the rigidity and strength of the material (single crystal silicon).

On the other hand, in the probe portion 138 'as shown in FIG. 18, the portion of the truncated triangular pyramid (the portion including the surface 144a) close to the lever portion 140 gains strength, so Increasing the aspect ratio does not significantly reduce the overall strength. Therefore, the upper limit of the aspect ratio and the height dimension of the probe section 138 ′ that can be actually realized is the probe section 13 shown in FIG.
8 higher than that.

In the second modification, as shown in FIG.
The etched surface 126 '' of the probe forming part 122 has a <110>
A plane 126a having an inclination θ with respect to a plane including
Plane 126b having an inclination φ (> θ) with respect to the plane including 0>
And a plane 126c having an inclination ψ (<θ) with respect to a plane including <110>.

When the above-described manufacturing method is similarly applied to the etching surface 126 ″ having such a shape, FIG.
As shown in FIG. 5, a silicon oxide wall 128 '' bent at two places reflecting the shape of the etched surface 126 '' is formed, and the tip of the probe base 130 '' has a truncated triangular pyramid. First, triangular pyramids having an aspect ratio higher than this are continuous, and the vertices are obliquely cut off.

As a result, as shown in FIG. 21, a triangular pyramid having an aspect ratio higher than that of the truncated triangular pyramid
A probe portion 138 '' having a tip portion whose top portion is obliquely cut off is obtained. The tip of the probe portion 138 ″ is formed by the (111) plane, the (100) plane, and the plane 144 ″ of silicon.
The surface 144 ″ reflects the shape of the etching surface 126 ″ of the probe forming portion 122, and has a plane 144 a having an inclination θ with respect to the surface including <110>, and <110> A plane 144b having an inclination φ (> θ) with respect to a plane including
110> plane 14 having a slope ψ (<θ) with respect to the plane including
4c.

The probe portion 138 ″ having this shape has three vertices 146 a, 146 b, and 146 c near its tip, and is particularly suitable for applications such as measurement of a vertical wall and measurement of the bottom surface of a groove. I have. By increasing the inclination φ of the surface 144b and lengthening the corresponding portion, it is possible to obtain a cantilever particularly suitable for measuring the wall and bottom of a deep groove.

Further, in the step shown in FIG. 7, the probe base 130 '' is set at 900 to 1000 ° C., preferably 950 ° C.
By oxidizing, the probe portion 138 ′ ″ in which the three vertices 146a, 146b, and 146c are sharpened is obtained as shown in FIG.

The probe 138 '''has three sharp apexes 148a, 148b, and 148c near the tip, so that it is particularly suitable for applications such as measurement of a vertical wall and measurement of a groove bottom. It is.

As described above, according to the manufacturing method described above,
A cantilever for SPM having a probe with a small radius of curvature at the tip can be easily and stably manufactured. Therefore, it is possible to provide an SPM cantilever that enables SPM measurement with higher resolution.

In addition, since the same probe portion can always be formed accurately and stably in cantilevers having various characteristics,
It is possible to provide a cantilever for SPM that does not deteriorate the resolution due to the difference in the PM measurement method and always enables the SPM measurement with high resolution.

Further, an SPM cantilever having a probe portion having a high aspect ratio can be easily and stably manufactured. Therefore, it is possible to provide an SPM cantilever that enables SPM measurement with higher resolution. The SPM cantilever having the probe portion having such a high aspect ratio is particularly suitable for a sample having a large step such as a groove of an optical disc.
Suitable for M measurement.

Further, the cantilever 142 manufactured by the manufacturing method of the present embodiment is, for example, as shown in FIG.
It has a surface 150 inclined with respect to the surface 152 of the forty. This surface 150 is defined by the etching surface 124 of the probe forming part 122 formed in the step of FIG.
As shown in FIG. 3, the etching surface 124 is formed by photolithography and dry etching, and the inclination η with respect to the surface including <110> can be appropriately selected by the maker of the cantilever.

Normally, the surface 152 of the lever portion 140 is used as the reflection surface of the optical sensor for detecting the movement of the lever portion 140, but the surface 150 can be used for this. In other words, the cantilever 142 has two reflecting surfaces that can be used for optical detection.

It is also possible to provide different sensors for each of the two reflecting surfaces 150 and 152, perform different SPM measurements for each reflecting surface, and detect different information separately. For example, the reflection surface 1 on the back side of the probe 138
While detecting the displacement of the tip of the probe in the Z direction using 50,
Using the reflection surface 152 of the lever 140, the lever 140
Can be detected.

In order to increase the reflectivity of the surface 152 of the lever portion and the surface 150 on the back side of the probe portion 138, the surface 152 of the lever portion and the probe portion 138 are subjected to the above-described manufacturing process (steps in FIGS. A step of coating the back surface 150 with a metal film or the like may be added.

In the present embodiment, the shape of the etching mask 110 for forming the second support 136 is rectangular, and therefore, as shown in FIG. The shape of 136 is a parallelepiped.

The shape of the second support portion 136 depends on the etching mask 110 formed in the step shown in FIG. Therefore, by changing the shape of the etching mask 110, the shape of the second support portion 136 can be changed. For example, as shown in FIG.
May be changed to a second support portion 136 ′ having a shape supporting the entire surface.

This cantilever 142 ′ is suitable for application to SPM measurement that vibrates the cantilever.
Since the support portion 136 ′ extends to the vicinity of the lever portion 140 and the rigidity of the first support portion 118, particularly the rigidity of the portion near the lever portion 140, is improved, vibration other than the lever portion 140 is reduced.

The first support portion 118 and the lever portion 14
The mutual relationship regarding the shape of 0 is determined by the patterning shape of the silicon nitride film 116 formed in the step of FIG. Therefore, by changing the patterning shape of the silicon nitride film 116, the first support portion 118 and the lever portion 140 are changed.
Can change each other's shape. For example, FIG.
As shown in the figure, the bottom surface of the first support portion 118 and the lever portion 1
The surface 40 may be formed so as to have a slope δ.

The cantilever 142 ″, when attached to a scanning probe microscope, cantilever 1 of FIG.
As compared with 42, a wider space can be secured between the second support portion 136 and the sample. That is, the cantilever 14 shown in FIG.
When the cantilever 142 of FIG. 23 and the cantilever 142 of FIG. 23 are attached to the scanning probe microscope so that the probe part 138 is in the same posture with respect to the sample, the second support part 136 of the cantilever 142 ″ (FIG. 25) is obtained. Is located farther from the sample than the second support portion 136 of the cantilever 142 (FIG. 23).

Next, several cantilever holding mechanisms for holding the cantilevers shown in FIGS. 23 to 25 will be described. All of the cantilever holding mechanisms described below
Since the cantilevers of FIGS. 23 to 25 are similarly held,
Hereinafter, the description will be made assuming that the cantilever 142 shown in FIG. 23 is typically held.

The cantilever holding mechanism 170 shown in FIG.
A holder main body 172 in which a groove 174 having a shape corresponding to the second support portion 136 of the cantilever 142 is formed;
The holder body 172 extends to extend over the groove 174.
And a leaf spring 176 fixed thereto.

In this cantilever holding mechanism 170, the second support portion 136 of the cantilever 142 is inserted into the groove 174 formed in the holder main body 172, and the leaf spring 176 provided on the side surface of the holder main body 172 has the second spring 176. The first support portion 118 contacts the second support portion 1
The cantilever 142 is held by pressing the contact surface 36 onto the bottom surface of the groove 174. Here, the contact surface means that the second support 136 is the first support 118
23, the surface is located opposite to the surface that supports (100), and in FIG. 23, it points to the (100) plane surrounded by the (111) plane. Hereinafter, such a surface is simply referred to as “applying surface”.

In the cantilever holding mechanism 170, a leaf spring 176 pressing the cantilever 142 is attached to the holder main body 1.
No component is provided on the lower surface of the holder body 172 facing the sample.
Therefore, a relatively large space can be secured between the sample and the sample. In addition, a leaf spring 176 is used to secure a space between the sample and the sample.
There is no limitation on the shape and size of the. Therefore, the thickness and shape of the leaf spring 176 can be changed relatively freely, and the cantilever 142 can be held more firmly.

The cantilever holding mechanism 17 shown in FIG.
0 ′ is a holder main body 17 in which a groove 174 having a shape corresponding to the second support portion 136 of the cantilever 142 is formed.
2 ′, and a hole 178 for a vacuum chuck is formed in the bottom surface of the groove 174.
9 is connected.

In the cantilever holding mechanism 170 ',
The second support portion 136 of the cantilever 142 is inserted into the groove 174 formed in the holder main body 172 ′, and the hole 178 is formed.
The cantilever 142 is held by sucking the contact surface of the second support portion 136 of the cantilever 142 via the.

The holder main body 172 ′ of the cantilever holding mechanism 170 ′ has no component for holding the cantilever 142. Therefore, a relatively large space can be secured between the sample and the sample. Further, the force for holding the cantilever 142 can be increased relatively freely by increasing the suction force of the suction device.

The cantilever holding mechanism 17 shown in FIG.
0 ″ is a holder main body 17 in which a groove 174 having a shape corresponding to the second support portion 136 of the cantilever 142 is formed.
2 '', a leaf spring 176 fixed to the holder body 172 '' so as to extend above the groove 174, and a piezoelectric body 180 fixed to the holder body 172 ''.

In the cantilever holding mechanism 170 ″,
The second support portion 136 of the cantilever 142 is inserted into the groove 174 formed in the holder body 172 ″, and the leaf spring 176 provided on the side surface of the holder body 172 ″ is attached to the first support portion 118 of the cantilever 142. The cantilever 142 is held by contacting and pressing the contact surface of the second support portion 136 against the bottom surface of the groove 174.

The piezoelectric body 180 is provided on the cantilever 14.
S in the excitation mode performed by vibrating the second lever 140
It is provided for PM measurement, and oscillates when an AC voltage is applied from a power supply unit (not shown), and the cantilever 14
Vibration is applied to the second lever section 140.

In the cantilever holding mechanism 170 ″, the leaf spring 176 for pressing the cantilever 142 is attached to the side surface of the holder main body 172 ″, so that a relatively large space can be secured between the holder and the sample. Further, the shape and size of the leaf spring 176 can be relatively freely changed, and the cantilever 142 can be held more firmly.

In the cantilevers described above, as shown in FIGS. 23 and 24, the second support portion has a parallelepiped shape or a similar shape. As described above, the shape of the second support portion depends on the etching mask 110 formed in the step of FIG. 2, and can be changed by changing the shape and position of the etching mask 110.

In the following, cantilevers having a second support portion having a shape different from those described above are shown in FIGS. 29 and 30, and cantilever holding mechanisms for holding these cantilevers are shown in FIGS. 31 and 32. .

The cantilever 182 shown in FIG. 29 has a second support portion 184 having a truncated pyramid shape. In order to form the second support portion 184 having this shape, in the process shown in FIG. 2, the shape of the etching mask 110 is a rectangle smaller than the portion of the silicon nitride film 116 where the first support portion is formed. Just place it so that it is almost in the center of the. As a result, in the wet anisotropic etching in the step of FIG.
1) Etching is performed so that the surface is exposed, and as a result, a truncated pyramid-shaped second support portion 184 is formed.

In the process of FIG. 2, the shape of the etching mask 110 is trapezoidal, so that the second support portion 184 ′ has a shape supporting the entire surface of the first support portion 118 as shown in FIG. Is manufactured. This cantilever 182 ', like the cantilever 142' of FIG.
Suitable for application to PM measurement.

Since the cantilever holding mechanisms of FIGS. 31 and 32 both hold the cantilevers of FIGS. 29 and 30 in the same manner, the cantilever 14 of FIG.
2 will be described.

The cantilever holding mechanism 190 shown in FIG.
A holder main body 192 in which a groove 194 having a shape corresponding to the second support portion 184 of the cantilever 182 is formed;
The holder body 192 extends so as to extend over the groove 194.
And a leaf spring 196 fixed to the

In the cantilever holding mechanism 190, the second support portion 184 of the cantilever 182 is inserted into the groove 194 formed in the holder main body 192, and the leaf spring 196 provided on the side surface of the holder main body 192 is connected to the cantilever 182. The first support portion 118 contacts the second support portion 1
The cantilever 182 is held by pressing the contact surface of the groove 84 against the bottom surface of the groove 194.

In the cantilever holding mechanism 190, the leaf spring 196 for pressing the cantilever 182 has the
Since it is attached to the side surface of the sample 92, a relatively large space can be secured between the sample and the sample. Further, the shape and size of the leaf spring 196 can be changed relatively freely, and the cantilever 142 can be changed.
Can be held more firmly.

The cantilever holding mechanism 19 shown in FIG.
0 ′ is a holder main body 19 in which a groove 194 having a shape corresponding to the second support portion 184 of the cantilever 182 is formed.
2 ′, a hole 198 for a vacuum chuck is formed in the bottom surface of the groove 194, and the hole 198 is
9 is connected.

In the cantilever holding mechanism 190 ',
The second support portion 184 of the cantilever 182 is inserted into the groove 194 formed in the holder main body 192 ′, and the hole 198 is formed.
The cantilever 182 is held by sucking the contact surface of the second support portion 184 of the cantilever 182 via the.

Since the holder main body 192 'of the cantilever holding mechanism 190' has no component for holding the cantilever 142, a relatively large space can be secured between the holder main body 192 'and the sample.

The holding mechanisms 190 and 190 'shown in FIGS. 31 and 32 are attached to the piezoelectric body 180 shown in FIG.
May be added.

The present invention is not limited to the above-described embodiment, but includes all implementations that do not depart from the gist of the invention.

For example, the cantilever holding mechanism shown in the embodiment of the present invention may be attached to a conventional device described below.

Japanese Patent Laid-Open No. 9-15250 discloses a cantilever integrally formed with a cantilever support, a cantilever holding mechanism (cantilever holder) for holding the cantilever support, and a scanner having one end fixed to the main body of the SPM device. And an optical lever type displacement detection sensor unit provided at the other end of the scanner.

In this configuration, the cantilever can be attached to and detached from the displacement detection sensor unit together with the cantilever holding mechanism, and the cantilever and the holding mechanism of the present invention can be attached to the displacement detection sensor unit according to the measurement.

The present specification includes the inventions described in the following items.

1. A cantilever for a scanning probe microscope to be attached to a cantilever holding mechanism provided in the scanning probe microscope, and a plate-like lever portion that can be elastically deformed, and a support that supports the lever portion in a cantilever manner. And the support has a surface that is applied to the holding mechanism,
This contact surface is perpendicular to the surface of the lever portion, and is a cantilever for a scanning probe microscope.

2. The cantilever for a scanning probe microscope according to item 1, wherein the support portion comprises a first support portion for supporting the lever portion and a second support portion having an abutting surface.

3. The cantilever for a scanning probe microscope according to paragraph 2, wherein the support is formed by processing a semiconductor substrate, and a contact surface of the second support is a (100) plane.

4. It has a plate-like lever part that can be elastically deformed, and a support part that supports the lever part in a cantilever manner. The support part has a contact surface perpendicular to the surface of the lever part. Is a cantilever holding mechanism for holding the cantilever for a scanning probe microscope, which is fixed to the holder body so as to extend over the groove and a holder body having a groove corresponding to the support portion of the cantilever. A cantilever holding mechanism having a leaf spring.

5. It has a plate-like lever part that can be elastically deformed, and a support part that supports the lever part in a cantilever manner. The support part has a contact surface perpendicular to the surface of the lever part. A cantilever holding mechanism that holds the cantilever for the scanning probe microscope that is provided. A cantilever holding mechanism having a suction device for sucking the support portion.

6. A cantilever for a scanning probe microscope according to any one of Items 1 to 3, wherein a probe is formed on the surface of the lever portion.

7. A cantilever holding mechanism for holding a cantilever for a scanning probe microscope in which a probe is formed on a surface of the lever portion according to the fifth item.

[0116]

According to the present invention, there is provided a cantilever capable of easily avoiding contact between the support portion of the cantilever and the measurement sample, and a holding mechanism for the cantilever.

[Brief description of the drawings]

FIG. 1 shows a first step in a method for manufacturing a cantilever according to an embodiment of the present invention.

FIG. 2 shows a second step following the step of FIG. 1 in the method of manufacturing a cantilever according to the embodiment of the present invention.

FIG. 3 shows a third step following the step in FIG. 2 in the method of manufacturing a cantilever according to the embodiment of the present invention.

FIG. 4 shows a fourth step following the step of FIG. 3 in the method of manufacturing a cantilever according to the embodiment of the present invention.

FIG. 5 shows a fifth step following the step of FIG. 4 in the method of manufacturing a cantilever according to the embodiment of the present invention.

FIG. 6 shows a sixth step following the step of FIG. 5 in the method of manufacturing a cantilever according to the embodiment of the present invention.

FIG. 7 shows a seventh step following the step of FIG. 6 in the method of manufacturing a cantilever according to the embodiment of the present invention.

FIG. 8 shows an eighth step following the step of FIG. 7 in the method of manufacturing a cantilever according to the embodiment of the present invention.

FIG. 9 shows a ninth step following the step of FIG. 8 in the method of manufacturing a cantilever according to the embodiment of the present invention.

FIG. 10 schematically shows a cantilever as a finished product obtained through the steps of FIGS.

11 shows a cantilever having a plane-symmetric shape with respect to the cantilever of FIG. 10 which can be manufactured by changing the patterning shape of the silicon nitride film in the step of FIG.

FIG. 12 shows a process of forming a lever portion in a method of manufacturing a cantilever according to an embodiment of the present invention, and (a) shows
4A, 4B, and 4C schematically show a cross section of the lever base in the step of FIG. 4, and FIG. 7C schematically shows a cross section of the lever base in the step of FIG.

FIG. 13 shows a shape of a probe forming portion formed in the step of FIG.

14 shows a probe base formed in the process of FIG. 6 based on the probe forming portion having the shape shown in FIG. 13;

FIG. 15 shows a probe section finally formed based on the probe base section shown in FIG.

FIG. 16 shows a first modification of the shape of the probe forming portion formed in the step of FIG.

17 shows a probe base formed in the step of FIG. 6 based on the probe forming portion having the shape shown in FIG. 16;

FIG. 18 shows a probe portion finally formed based on the probe base portion shown in FIG.

FIG. 19 shows a second modification of the shape of the probe forming portion formed in the step of FIG.

20 shows a probe base formed in the process of FIG. 6 based on the probe forming portion having the shape shown in FIG. 19;

FIG. 21 shows a probe section finally formed based on the probe base section shown in FIG.

FIG. 22 shows a probe portion finally formed by performing a low-temperature thermal oxidation process on the probe base portion shown in FIG.

FIG. 23 shows a cantilever provided with a parallelepiped-shaped second support portion manufactured by the method of manufacturing a cantilever according to the embodiment of the present invention.

24 is similar to a parallelepiped supporting substantially the entire first support portion, which can be manufactured by changing the shape of an etching mask for forming the second support portion formed in the step of FIG. 2; 9 shows a cantilever with a shaped second support.

FIG. 25 shows a cantilever in which the surface of the lever portion is inclined with respect to the bottom surface of the first support portion, which can be produced by changing the patterning shape of the silicon nitride film formed in the step of FIG. I have.

26 shows a cantilever holding mechanism for holding the cantilever shown in FIGS. 23 to 25. FIG.

FIG. 27 shows another cantilever holding mechanism for holding the cantilever shown in FIGS. 23 to 25.

FIG. 28 shows yet another cantilever holding mechanism having a function of vibrating the lever portion of the cantilever for holding the cantilever shown in FIGS. 23 to 25.

29 shows a cantilever provided with a truncated quadrangular pyramid-shaped second support portion which can be manufactured by changing the shape of an etching mask for forming the second support portion formed in the step of FIG. 2; ing.

FIG. 30 shows a truncated square pyramid supporting substantially the entire first support portion, which can be manufactured by changing the shape of an etching mask for forming the second support portion formed in the step of FIG. 2; 5 shows a cantilever with a second support of similar shape.

FIG. 31 shows a cantilever holding mechanism for holding the cantilever shown in FIGS. 29 and 30.

FIG. 32 shows another cantilever holding mechanism for holding the cantilever shown in FIGS. 29 and 30.

[Explanation of symbols]

 118 First support portion 136 Second support portion 138 Probe portion 140 Lever portion 142 Cantilever 170 Cantilever holding mechanism 172 Holder body 174 Groove 176 Leaf spring

Claims (3)

[Claims] 1. A cantilever for a scanning probe microscope attached to a cantilever holding mechanism provided in a scanning probe microscope, wherein the plate-like elastically deformable lever portion and a support for supporting the lever portion in a cantilever manner. A cantilever for a scanning probe microscope, wherein the support portion has a surface applied to the holding mechanism, and the applied surface is perpendicular to the surface of the lever portion. And a support portion for supporting the lever portion in a cantilever manner. The support portion has a contact surface perpendicular to a surface of the lever portion. A cantilever holding mechanism for holding a cantilever for a scanning probe microscope, which is fixed to the holder body with a groove formed in a shape corresponding to the support portion of the cantilever, and extending above the groove. A cantilever holding mechanism having a leaf spring. And a support portion for supporting the lever portion in a cantilever manner. The support portion has a contact surface perpendicular to a surface of the lever portion. A cantilever holding mechanism for holding a cantilever for a scanning probe microscope, which has a groove formed in a shape corresponding to the support of the cantilever, and a cantilever through a suction hole formed on the bottom surface of the groove. A cantilever holding mechanism having a suction device for sucking the support portion.