JPH0721968A - Cantilever type displacement element, cantilever type probe using the displacement element, and scanning type probe microscope and data processer using the probe - Google Patents

Abstract

PURPOSE:To suppress short-circuiting so as to improve the durability, as well as to prevent a sticking phenomenon so as to simplify the manufacturing process and to improve the yield, by providing a projecting position of an insulating material to the surface of a substrate or the surface of a cantilever side, to a cantilever type dispalcement element. CONSTITUTION:On the surface of a silicon substrate 101, a silicon nitride membrane 102 is laminated, and after a tungsten membrane is laminated thereover, a fixed electrode 103 is formed by a patterning. Furthermore, a silicone nitride to be an insulator is laminated, and by forming a projecting position 104 by a patterning, short-circuiting between the fixed electrode and an opposite electrode is prevented, as well as a sticking when the cantilever is released is prevented, in the manufacturing process thereafter. After that, a sacrificing layer 109, a multi-crystal silicon membrane 106, and a silicon nitride membrane 107 are laminated in order, and after a heat treatment is applied, the membranes 106 and 107 are made into a cantilever form by a patterning, and then, the sacrificing layer 109 is removed by an etching, and a clearance 105 is formed between the cantilever 106 and the fixed electrode 103.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a scanning tunneling microscope (hereinafter referred to as "STM") and an atomic force microscope (hereinafter referred to as "STM").
Scanning probe microscope (hereinafter referred to as "SFM")
The present invention relates to a displacement element (actuator) having a cantilever structure (hereinafter referred to as “PM”) and the like, an SPM using the same, an information processing apparatus, and the like.

[0002]

2. Description of the Related Art In recent years, an STM capable of directly observing the electronic structure of surface atoms of a conductor has been developed by Gie Winig et al. (Fervetica Physika Actor, 55, 726 (1
982). Since then, SPM equipment that obtains various information by scanning a probe with a sharp tip, and microfabrication technology that applies SPM to exert electrical, chemical or physical action on the substrate. Is being researched and developed. In addition, using semiconductor microfabrication technology and micromechanics technology, for example, using a silicon wafer as a substrate,
A compact SPM device in which a probe is fabricated on a thin film cantilever has been developed.

On the other hand, there is an increasing demand for recording / reproducing devices, especially recording devices having a large capacity for computer calculation information and the like. Due to the progress of semiconductor process technology, microprocessors are downsized and the calculation ability is improved. Therefore, downsizing of the recording apparatus is desired. In order to meet these requirements, the shape of the surface of the recording medium is changed by applying a voltage from a converter including a microprobe for generating a tunnel current existing on a driving unit whose distance from the recording medium can be finely adjusted. A recording / reproducing apparatus has been proposed in which the minimum recording area is 10 nm square by performing recording and writing according to the above, and reading information by detecting a change in tunnel current due to a change in shape.

As a method of driving the cantilever displacement element mounted on the above-described SPM and the recording / reproducing apparatus to which the SPM is applied, for example, a piezoelectric type in which the cantilever has a piezoelectric bimorph structure, or a counter electrode and a substrate formed on the cantilever are used. There is an electrostatic type in which a beam is displaced by applying an electrostatic force by applying a voltage to the fixed electrode formed on the upper side, and the electrostatic type is characterized by a simple structure and a high degree of freedom in materials.

An example of the electrostatic type is disclosed in Japanese Patent Laid-Open No. 61-2.
There is a cantilevered element proposed in 06148. As shown in FIG. 18, after the fixed electrode 402 was provided on the Si wafer 401 by impurity doping, Si
The epitaxial growth 403 is performed, the counter electrode 404 is provided again by impurity doping, and then the non-doped Si layer in the middle is removed to form the cantilever 405. An insulating layer 406 is formed on the cantilever electrode, and a probe 407 for detecting a tunnel current and a lead electrode 408 are provided on the insulating layer 406. Also,
An AFM having the same structure as the above is disclosed in Japanese Patent Laid-Open No. 63-3.
09802. This is to detect the deflection of the cantilever due to a small force by the change in electrostatic capacity, and the same element configuration as the electrostatically driven cantilever can be used.

[0006]

However, in the electrostatic cantilever displacement element described above, when the cantilever is largely displaced by applying a relatively large voltage, the cantilever becomes large due to large unevenness or dust on the sample surface. When displaced, an electrical short circuit may occur between the narrowed fixed electrode and the counter electrode, causing great damage to the element or the electrical control system.

Further, the conventional technique has the following problems in the manufacturing method. As a method for producing a cantilever on the surface of a substrate, semiconductor fine processing techniques such as photolithography and etching are usually applied. As a result, it is possible to form a laminated structure of a conductive film or an insulating film having an arbitrary shape on the surface of the silicon substrate, and a beam-shaped structure or an electrode is freely produced by combining them. Generally, a sacrificial layer has been used to fabricate a structure such as a cantilever at a position separated from the substrate surface by a narrow space of about 10 μm or less. This sacrificial layer is a thin film layer for forming a space by being removed later. Beams, electrodes and probes are formed on the surface of the sacrificial layer, and the sacrificial layer is finally removed. Here, in order to completely remove the sacrificial layer without damaging important parts such as the beam, the electrode, and the probe, the sacrificial layer is dissolved and removed using a liquid such as acid or alkali.
Therefore, it is necessary to dry the substrate after removing the sacrificial layer,
At this time, as the liquid that has entered the gap between the beam and the substrate surface evaporates, the beam is bent to the substrate surface side by the surface tension of the liquid, and eventually the beam sticks to the substrate surface . In order to avoid this sticking phenomenon, a method is used in which after the sacrificial layer is removed and before drying, the sublimable material is allowed to penetrate into the gap between the beam and the substrate to be solidified and then sublimated in a vacuum. Specifically, for example, after substituting with alcohol while maintaining the wet state for removing the sacrificial layer, further substituting with paraffinic benzene, which is a sublimable material, into a heating liquid, taking out into the atmosphere and solidifying at room temperature. It was installed in a vacuum container to sublimate paradichlorobenzene. In the production of cantilevers and the like, a step for avoiding sticking using such a sublimable material is indispensable, and since this method is not yet perfect, it has been one of the causes for lowering the yield.

Further, in the conventional element, since the cantilever surface is formed in the same plane as the substrate surface as shown in FIG. 18, when the probe is moved close to the sample surface to scan the substrate surface and the sample surface. It was necessary to use the surfaces very close together.

For this reason, the elements formed on or around the substrate and the protrusions such as wire bonding are likely to come into contact with the sample surface, so that the height of the elements and wiring on the substrate surface must be designed to be as small as possible. In addition, even when the substrate is driven in the three axis directions, it is necessary to pay close attention to avoid contact. This problem becomes more noticeable than the case where a plurality of cantilevers are arranged on the same substrate and a multi-probe is used, which requires great difficulty in designing and driving the device.

Therefore, in view of the problems of the prior art as described above, an object of the present invention is to prevent a decrease in yield with a simple structure and to prevent an electrical short circuit due to a large displacement of the cantilever. It is an object of the present invention to provide a mold displacement element or a cantilever displacement element capable of preventing contact between the sample surface and element wiring or the like when scanning the sample surface, and further increasing the degree of freedom in element design.

Still another object of the present invention is to provide a cantilever type probe using the above cantilever type displacement element, a scanning probe microscope, an information processing device and the like.

[0012]

The present invention, which has been made to achieve the above object, firstly has a fixed electrode formed on a substrate and a counter electrode facing the fixed electrode. A cantilever-type displacement element having a cantilever provided on a substrate, characterized in that it has a convex portion between the substrate and the cantilever and on the substrate surface or the substrate-side surface of the cantilever. Second, a cantilever type displacement element comprising a fixed electrode formed on a substrate and a cantilever provided on the substrate, the cantilever having a counter electrode facing the fixed electrode. A cantilever-type displacement element, characterized in that an insulating layer protruding toward the free end side from the counter electrode is formed on the cantilever, and thirdly, it is formed on a raised portion of the substrate. A fixed electrode, a cantilever type displacement element comprising a cantilever provided on the substrate so as to along the raised portion having a counter electrode opposed to the fixed electrode.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of a cantilever type probe constructed by providing a sharp probe at the free end of the cantilever type displacement element of the first cantilever type displacement element of the present invention.
1A is a longitudinal sectional view, and FIG. 1B is AA ′ in FIG.
It is sectional drawing in the surface. In the figure, 101 is a substrate and 10
2 is an insulating film, 103 is a fixed electrode, and 104 is a fixed electrode 10.
3 is a convex portion formed on the substrate 3, 106 is a conductive cantilever supported on the substrate, 107 is an insulating film, and 108 is a probe. In this configuration, a portion of the conductive cantilever 106 facing the fixed electrode 103 also serves as a counter electrode, and by applying a voltage between them, electrostatic force causes the cantilever in the direction of the arrow in FIG. 1B. 106 can be displaced.

In the first cantilever type displacement element of the present invention, since the convex portion 104 is provided, the cantilever 106 is provided.
When the substrate is dried after the sacrificial layer removing step for forming the void 105 between the substrate 101 and the substrate 101, it is not necessary to substitute a sublimable material. That is, when the liquid between the cantilever and the substrate surface decreases due to evaporation, the cantilever is deflected toward the substrate side and the cantilever and the substrate come into contact with each other. At this time, the contact surface between the cantilever and the substrate surface is the convex shape. There is only a part, and by reducing this contact area, the sticking phenomenon does not occur if the force (product of the spring constant and the amount of displacement) that the cantilever tries to return to the original shape overcomes the sticking force.

When the convex portion is made of an insulating material, the sticking prevention effect can be obtained, and an electrical short circuit is generated even when the fixed electrode and the counter electrode approach or contact each other. It is possible to prevent it, and the durability of the element and its electric control system is improved.

In the example shown in FIG. 1, the convex portion is formed on the surface of the fixed electrode. However, even if it is the surface of the counter electrode on the cantilever side, or between the substrate and the cantilever, it is not on these electrodes. It may also be formed on the substrate surface or the substrate surface side of the cantilever. The shape and number of the convex portions are not particularly limited, and can be appropriately designed so as to prevent the sticking phenomenon described above.

Next, the second cantilever type displacement element of the present invention will be described.

FIG. 7 is a schematic view showing an example of a cantilever type probe constituted by providing a sharp probe on the free end of the cantilever type displacement element of the second cantilever type displacement element of the present invention, in which 201 is a substrate and 202 is an insulator. The film and 203 are fixed electrodes. The cantilever portion includes the counter electrode 206 and the insulating layer 20.
The extraction electrode 213 is formed on the cantilever, and the probe 208 for inputting / outputting information is formed on the extraction electrode 213.

Insulating layer 207 forming a cantilever
Are formed so as to project from the counter electrode 206 on the free end side of the cantilever.

In this structure, the fixed electrode 203 and the counter electrode 2
By applying a voltage between the cantilever and 06, the cantilever can be deflected and displaced in a direction perpendicular to the substrate surface by electrostatic force. At this time, the free end of the cantilever is displaced the most, but even when the amount of displacement toward the substrate is large, the fixed electrode 203 contacts the insulating layer 207 and does not contact the counter electrode, so that the electrical contact between the electrodes is reduced. Avoid short circuit.

In the second cantilever type displacement element of the present invention, in order to more surely avoid the electrical short circuit between the electrodes, the fixed electrode 203 is moved in the direction of the free end of the cantilever as shown in FIG. The counter electrode 206 is preferably formed longer than the counter electrode 206. Further, as shown in FIG. 9, the insulating layer 207 at the free end of the cantilever is projected toward the substrate surface side, and the insulating layer at the free end of the cantilever and the fixed electrode 203 are formed.
The distance between and is preferably shorter than the distance between the counter electrode 206 and the fixed electrode 203.

Next, a third cantilever type displacement element of the present invention will be described.

FIG. 11 is a configuration diagram best showing the characteristics of the third cantilever type displacement element of the present invention, and FIG.
Is a plan view seen from the upper surface of the substrate, and FIG.
It is sectional drawing in dashed line AA 'in (a).

In FIG. 11, 301 is a substrate, and 30
2 is a fixed part, and 303 is a cantilever. A raised portion 304 is provided in a portion below the cantilever on the substrate, and the cantilever 303 has the raised portion 304.
It inclines upward so that it follows. A fixed electrode 305 is provided on the upper surface of the raised portion 304, and a counter electrode 306 is formed on the lower surface of the cantilever. The fixed electrode 305 and the counter electrode 306 are individually drawn out onto the substrate, and voltage can be applied to each.

In this configuration, the fixed electrode 305 and the counter electrode 3
By applying a voltage between the cantilever 303 and 06, the tip of the cantilever 303 can be slightly displaced in a direction perpendicular to the substrate surface by electrostatic force.

The third cantilever type displacement element of the present invention is
The fixed electrode 305 is provided on the raised portion 304, and the fixed electrode 30
Since the distance between the counter electrode 5 and the counter electrode 306 is not increased, the displacement portion can be moved away from the substrate surface without reducing the displacement amount of the cantilever tip per drive voltage. For this reason, it is possible to increase the margin in the height direction of the other elements and wirings arranged on the substrate from the substrate surface, and it is possible to increase the degree of freedom in design.

Further, a probe is provided at the free end of the cantilever,
Even when used in a scanning probe microscope, the distance between the sample surface and the substrate surface can be large, so contact between the sample and the substrate and other peripheral devices can be avoided when approaching or scanning the sample. It will be easy.

Furthermore, in a device in which a plurality of cantilever displacement elements according to the third aspect of the present invention are arranged on the same substrate and integrated with a semiconductor element, or an information processing apparatus using the same, they are necessarily mounted together. Since a large number of devices, wirings, driving mechanisms, etc. are provided, it is advantageous in designing and driving that the distance between the sample surface and the substrate surface is large.

In the above-described first to third cantilever type displacement elements of the present invention, the substrate material is a semiconductor,
Metal, glass, ceramics or the like can be used, but when a plurality of elements are formed on the same substrate, a material having small surface irregularities is preferable, for example, Corning # 70.
59 fusion, fused quartz, and polished surface #
7059, quartz, a silicon wafer, or the like can be used. A single crystal silicon wafer is used when an amplifier for amplifying a tunnel current, a multiplexer for driving an element and selecting a tunnel current, a shift register, and the like are mounted on a substrate.

As a method of forming the element, a conventionally known technique, for example, a thin film forming technique such as a vacuum vapor deposition method, a sputtering method, a chemical vapor deposition method or the like which is generally used in the semiconductor industry, a photolithographic technique and etching are used. The technique can be applied, and its manufacturing method does not limit the present invention. Further, although the element which is driven and displaced by the electrostatic force is described in the above description, it is obvious that the element can be used as a capacitance detection type element without changing the element configuration.

Further, the cantilever type probe constituted by providing a sharp probe at the free end of the cantilever type displacement element of the present invention is an electrostatic drive type scanning in which the probe is moved close to the sample surface for scanning. Type probe microscope or a scanning probe microscope of electrostatic capacity type that scans by contacting the sample surface with the sample, or by bringing the probe close to the recording medium and applying a voltage between the probe and the recording medium. The present invention is applied to an information processing apparatus that records and / or reproduces information, and a processing apparatus that changes the characteristics of the sample surface by exerting an electrical, chemical or physical action on the vicinity of the sample surface.

[0033]

EXAMPLES Examples of the present invention will be described below.

Embodiment 1 A cantilever type probe using the first cantilever type displacement element of the present invention as shown in FIG. 1 is a capacitance type AFM.
An example applied to will be described.

First, a method of manufacturing the cantilever type probe of this embodiment will be described with reference to FIG. (A) A silicon nitride film 102 is formed on a surface of a silicon substrate 101 having a crystal plane of (100) by chemical vapor deposition (CV).
A thickness of about 0.5 μm was deposited by the method D). Next, a tungsten film is formed to a thickness of about 0.5 μm by a normal sputtering film forming method.
After the m deposition, patterning was performed by a normal photolithography etching method to form the fixed electrode 103. (B) As in the case of forming the silicon nitride film 102, C
After depositing silicon nitride to a thickness of about 0.5 μm by the VD method,
The convex portion 104 was formed by patterning by a normal photolithographic etching method. Here, if the material forming the convex portion is made of an insulator as in this embodiment, the effect of preventing sticking when releasing the cantilever in the manufacturing process and the effect of preventing short circuit between the fixed electrode and the counter electrode are achieved. Both effects are obtained. Further, when the convex portion is made of a conductive material such as metal, an effect of preventing sticking can be obtained. (C) As the sacrificial layer 109, silicon oxide was deposited to a thickness of about 2 μm by the bias sputtering method. Here, the bias sputtering method is used to smooth the surface of the sacrificial layer 109 as shown in the figure, and the method is not limited to the bias sputtering method as long as the surface of the sacrificial layer can be smoothed. Sacrificial layer 10
When the surface of 9 has a convex shape that reflects the shape of the convex portion 104, the substrate-side surface of the cantilever formed in the upper layer of the sacrificial layer has its inverted shape (concave shape), and the substrate surface and the cantilever surface when the sacrificial layer is removed. Since the contact area with is large, it becomes easy to stick. In addition, there is a possibility of short-circuiting, which reduces the effect of the present invention.

Further, a polycrystalline silicon film 106 is deposited to a thickness of about 1.2 μm by the chemical vapor deposition method, phosphorus ions are implanted at about 1 × 10 ¹⁶ cm ^−2, and then the thickness is determined by the chemical vapor deposition method. A silicon nitride film 107 having a thickness of about 0.3 μm was formed. After performing activation heat treatment at 1100 ° C. for 60 minutes in a nitrogen atmosphere, the polycrystalline silicon film 106 and the silicon nitride film 107 were patterned into a cantilever shape by a normal photolithographic etching method. (D) A tungsten probe 108 was formed by the Spindt method near the tip of the cantilever. As for the formation of the probe, any manufacturing method such as a method of adhering a tungsten wire probe by an electropolishing method other than the Spindt method using oblique vapor deposition may be used. (E) After removing the silicon oxide sacrificial layer 109 by etching with a buffered hydrofluoric acid solution, it was replaced with alcohol and the substrate was dried. Cantilever 106 and fixed electrode 104
A void 105 was obtained between the two, and the cantilever-type probe manufacturing process was completed.

In this embodiment, the cantilever flexes toward the substrate surface and tends to stick to the substrate surface during the above-mentioned substrate drying. It was released due to the springiness of the cantilever, and no sticking occurred. As a result, the process using a sublimable material such as the conventional method can be simplified and the yield is improved.

The device shown in FIG. 6 was constructed using the cantilever type probe manufactured as described above. Since FIG. 6 has a configuration in which it can be used as an electrostatic capacity type AFM and also as an electrostatic drive type STM, the probe 108 of the cantilever type probe is provided on the extraction electrode (not necessary for the AFM) formed on the cantilever. It is shown as being formed.

Reference numeral 120 is a sample, 121 is a fixed electrode wiring, 1
22 is wiring to the cantilever which also serves as the counter electrode, 123
Is a capacitance detection unit (electrostatic drive unit in STM). Further, 124 is a tunnel current detection unit, 125 is a lead electrode wiring, and 126 is a sample wiring, and these are unnecessary in the AFM. An element and an electric control system for two-dimensionally moving the cantilever type probe along the sample surface are omitted.

AF on the surface of the sample was performed using the apparatus shown in FIG.
As a result of observing the M image, an AFM image similar to that of a conventional cantilever type probe having no convex portion was obtained. At this time, even in the case of a sample having unevenness of about voids 105 on the surface, the counter electrode and the fixed electrode were obtained. There is no electrical short circuit between the and, and there is no damage like when using a conventional cantilever type probe, and the durability of the device is improved.

Example 2 Another example in which the cantilever type probe using the first cantilever type displacement element of the present invention is applied to a capacitance type AFM will be described.

FIG. 3 shows a cantilever type probe of this embodiment. FIG. 3A is a schematic plan view showing a main part of the cantilever type probe with a dotted line for easy understanding, and FIG. 3B is a cross-sectional view taken along the line AA ′ of FIG. 3A. 3 (c) schematically shows the BB 'cross section of FIG. 3 (a).

In FIG. 3, the same reference numerals as those in FIG. 1 denote equivalent members, and 110 is a silicon nitride protrusion integrated with the insulating film (silicon nitride) 102, and 11
Reference numeral 1 is a convex portion on the surface of the fixed electrode (tungsten) 103 reflecting the shape of the protrusion 110, and 112 is a wiring of the fixed electrode 103.

In the present embodiment, a thin film projection which is the source of the convex portion 111 is formed in a part of the silicon nitride film 102. That is, after thickly depositing silicon nitride on the surface of the silicon substrate 101, patterning was performed by a normal photolithography etching method so that the protrusions 110 remained in a dot shape. After that, tungsten was deposited on the entire surface as the fixed electrode 103. Therefore, when the cantilever is largely displaced to the fixed electrode side, there is a possibility of short circuit. In the present embodiment, the other manufacturing methods are basically the same as those in the first embodiment, and therefore will be omitted.

The present embodiment is characterized in that the convex portion is formed into a plurality of dots to further reduce the area of the convex portion. Even with a soft cantilever which is easy to stick (small spring constant), the above-mentioned substrate drying is performed. Sometimes it has the feature that it does not stick to the substrate surface. Therefore, as in the first embodiment, the manufacturing process is simplified, the yield is improved, and the degree of freedom in designing the cantilever is increased. Further, when the cantilever type probe of the present example was installed in the AFM apparatus shown in FIG. 6 as in the case of Example 1 and an AFM image of the sample surface was observed, it was found that the same AFM image as the conventional cantilever type probe having no convex portion was formed. The image was obtained.

Embodiment 3 An example in which the cantilever type probe using the first cantilever type displacement element of the present invention is applied to an electrostatic drive type STM will be described.

FIG. 4 shows a cantilever type probe of this embodiment. FIG. 4A is a schematic plan view showing the main part of the cantilever type probe with a dotted line showing the cantilever for easy understanding, and FIG. 4B is a sectional view taken along the line AA ′ of FIG. 4A. 4 (c) schematically shows the BB 'cross section of FIG. 4 (a).

In FIG. 4, the same reference numerals as those in FIG. 1 denote the same members, and 103a and 103b.
Is a fixed electrode, 112a and 112b are fixed electrodes 103a,
A wiring 103b and a lead electrode 113 are formed on the insulating film 107.

The fixed electrode is divided into two electrodes because the electric field formed between the fixed electrode and the counter electrode is made non-uniform by applying a voltage, and the tip of the probe 108 is biaxially displaced by twisting the cantilever. Is. Insulating convex part 1
As 04, a silicon nitride film was patterned and used. The materials for the other parts and the basic manufacturing method are the same as those in the first or second embodiment, and will be omitted.

In the structure of this embodiment, as in the first embodiment, the sticking phenomenon during manufacturing and the electrical short circuit during driving can be prevented. When an STM apparatus as shown in FIG. 6 was constructed using the cantilever type probe of this example and the sample surface was observed, it was found that the characteristics were basically similar to those of the conventional type having no convex portion. showed that.
However, even in the case of a sample having large surface irregularities, the counter electrode and the fixed electrode were not electrically short-circuited, and the durability of the device was improved.

Embodiment 4 Another example in which the cantilever type probe using the first cantilever type displacement element of the present invention is applied to the electrostatic drive type STM will be described.

FIG. 5 shows a cantilever type probe of this embodiment. FIG. 5A is a schematic plan view showing the main part of the cantilever type probe with a dotted line showing the cantilever for the sake of clarity, and FIG. 5B is a cross-sectional view taken along the line AA ′ of FIG. 5A. 5 (c) schematically shows a cross section taken along the line BB 'of FIG. 5 (a).

In FIG. 5, the same reference numerals as those in FIG. 4 denote the same members. The basic manufacturing method is the same as that of the first embodiment, and will be omitted. However, in Examples 1 to 3, the convex portion 104 was formed on the fixed electrode side, but in this example, it was formed on the back side (the surface on the substrate side) of the cantilever also serving as the counter electrode. The effect of preventing the short circuit between the counter electrode and the fixed electrode and the sticking phenomenon due to this convex portion is not significantly different from those of Examples 1 to 3 manufactured on the fixed electrode side. However, since the resonance frequency and the spring constant of the cantilever are slightly increased due to the addition of the convex portion, it is necessary to consider it, and it is not desirable to provide the convex portion larger than necessary.

In the case where the conventional cantilever type probe having the same structure but having no convex portion is incorporated into the STM device as shown in FIG. 6 and used, when the cantilever is largely bent, the cantilever type probe is There was a case where the fixed electrode was electrically short-circuited, but it was improved by adopting this configuration. Also in the manufacturing process,
The cantilever having the convex portion of this example could be easily released without sticking to the substrate even after the sacrifice layer was removed.

Example 5 An example will be described in which the STM apparatus shown in FIG. 6 incorporating the cantilever type probe in Example 4 shown in FIG. 5 is used as a processing apparatus.

By placing a cantilever probe having a convex portion and a GaAs wafer as a sample in a vacuum container and observing STM with chlorine as a reactive gas, the GaAs sample surface is locally observed. It could be etched. In addition, by introducing WF ₆ as a reactive gas, W is introduced only on the STM-observed portion of the sample surface.
Was able to be deposited. As described above, the cantilever type probe having the convex portion according to the first aspect of the present invention could be incorporated into the processing apparatus and used.

As described in Examples 1 to 5, the cantilever type probe having the convex portion according to the first aspect of the present invention is
It can be used as FM, STM, processing equipment,
It was possible to use them as a composite device of them.

Embodiment 6 An example in which a cantilever type probe using the second cantilever type displacement element of the present invention as shown in FIG. 7 is applied to an STM device will be described.

First, a method of manufacturing the cantilever type probe in this embodiment will be described with reference to the sectional views showing the manufacturing process of FIG.

S in which a thermal oxide film 202 of 5000 Å is formed
On the surface of the i substrate 201, an aluminum film having a thickness of 1000 liters was formed by a sputtering method, and a pattern was formed by a photo etching method to form a fixed electrode 203. Subsequently, zinc oxide is formed as a sacrificial layer 209 by a sputtering method,
Pattern formation was performed by the photo etching method. Further, after forming a resist pattern, an aluminum film having a thickness of 3000 Å was formed by a sputtering method, and a pattern was formed by a lift-off method to form a counter electrode 206. At this time,
The counter electrode 206 is formed so as to extend over the thermal oxide film 202 and the sacrificial layer 209, and further, the end portion 221 on the sacrificial layer 209.
The position was formed 5 μm shorter than the end 222 of the fixed electrode 203 (see FIG. 8A).

Next, a silicon oxide film having a thickness of 1 μm is formed by the sputtering method, and the counter electrode 20 is formed by the photoetching method.
A pattern was formed so as to cover 6 and an insulating layer 207 was formed. At this time, the end portion 223 of the insulating layer 207 was formed so as to fit on the end portion 222 of the fixed electrode 203 (FIG. 8B).
reference).

Next, 3000 Å of gold was deposited by the vacuum evaporation method, and the extraction electrode 213 was formed on the insulating layer 207 by the photo etching method (see FIG. 8C).

Next, the probe 208 is placed on the extraction electrode 213.
After forming, the zinc oxide of the sacrificial layer 209 was removed with an aqueous acetic acid solution to obtain a cantilever probe (see FIG. 8D).

400 μm in length manufactured as described above
When the cantilever was displaced by applying a voltage to the counter electrode and the fixed electrode of the cantilever type displacement element having a width of m and a width of 100 μm, the cantilever was displaced in a direction perpendicular to the substrate surface (Z direction) by 0.2 μm / V
It turned out to be displaced by. Further, the cantilever type probe was incorporated into an STM device and evaluated.

FIG. 10 is a block diagram of the STM device.
In the figure, 231 is a bias applying power source, 232 is a tunnel current amplifier circuit, 233 is a cantilever driving driver, 2
34 is a cantilever type displacement element, 235 is a sample, 2
Reference numeral 36 is an XY direction fine movement mechanism. Here, the tunnel current It flowing between the probe 208 and the sample 235 is detected, feedback is performed so that It becomes constant, the cantilever is driven, and the interval between the probe 208 and the sample 235 is kept constant. There is. Here, as the sample 235, 500 Å vapor-deposited gold on silicon was used, and when observed with a bias current of 1 nA and a scan area of 1 μm × 1 μm, an STM image of gold with a grain size of about 300 Å could be obtained with good reproducibility. . Further, although the STM operation was continuously performed, the counter electrode and the fixed electrode were not electrically short-circuited, and the durability of the device was improved.

If desired response and rigidity of the cantilever type displacement element are required, the cantilever may be designed by changing its length and thickness.

Example 7 Another example of a cantilever type probe using the second cantilever type displacement element of the present invention will be described.

FIG. 9 is a schematic view of the cantilever type probe of this example, and a cantilever type probe was prepared in the same manner as in Example 6 except that the shape of the insulating layer 207 of the cantilever was changed. Specifically, in the step of FIG. 8A, after forming the counter electrode 206, the sacrifice layer 209 is etched by 2000 Å using the counter electrode 206 as a mask to form a step in the sacrifice layer 209, and then the insulating layer 207 is formed. Then, pattern formation was performed to manufacture a cantilever type probe having a shape as shown in FIG. An STM device as shown in FIG. 10 was constructed using this cantilever probe and evaluated in the same manner as in Example 6, and the same results as in Example 6 were obtained.

Further, the cantilever type probe according to the second aspect of the present invention can be applied to the AFM, STM, processing apparatus, and their combined apparatus, like the cantilever type probe according to the first aspect of the present invention described above.

Embodiment 8 In this embodiment, a third cantilever type displacement element of the present invention as shown in FIG. 11 is manufactured, and the manufacturing method thereof will be described with reference to FIG.

First, 3 Si ₃ N ₄ was deposited on the surface of the single crystal silicon substrate 301 having a plane orientation (100) by a low pressure CVD method.
A film having a thickness of 00 nm is formed as a protective film. Then, photolithography was performed to form a resist pattern 311 (FIG. 12).
(See (a)).

Next, the anisotropic etching of silicon was performed by utilizing the fact that the etching rate was largely different depending on the plane orientation to form the raised portion 304 in which the (111) plane was exposed (see FIG. 12B).

Next, Cr was deposited to a thickness of about 1 nm by sputter deposition to secure adhesion, and Au was then deposited to a thickness of 100 nm to form an electrode film 312 (see FIG. 12C).

Next, the electrode film 312 is formed by photolithography.
The unnecessary portion of was removed by etching to form the fixed electrode 305 (see FIG. 12D).

Next, ZnO was deposited to a thickness of 2 μm by sputter deposition to form a sacrificial layer film 313 (see FIG. 12 (e)).

Next, the sacrifice layer film 31 is formed by photolithography.
The unnecessary portion of No. 3 was removed by etching to leave the sacrificial layer 314 (see FIG. 12F).

Further, Cr is deposited on the above by sputtering deposition.
After forming a film with a thickness of 0 nm and forming Au with a thickness of 200 nm, C is formed again.
10 nm of r was vapor-deposited. The unnecessary portion of the electrode film thus formed was removed by etching to form the counter electrode 306 (see FIG. 12 (g)).

Next, SiO ₂ is deposited to a thickness of 1 μm by sputter deposition.
A film was formed to form an elastic layer 315 (see FIG. 12 (h)).

Photolithography is performed again, and the elastic layer 31
The unnecessary portion of 5 is removed by etching, and the cantilever 303
The remaining part was left (see FIG. 12 (i)).

Finally, the sacrifice layer 314 is removed by dry etching to form the cantilever 303 on the substrate.
Was formed, and a cantilever type displacement element was obtained (Fig. 12).
(See (j)).

Here, the solution and gas used for etching were KI: I ₂ aqueous solution for Au, (NH ₄ ) ₂ Ce (NO ₃ ) ₆ : HClO ₄ aqueous solution for Cr, and Z.
An acetic acid aqueous solution was used for nO. An aqueous solution of KOH was used for anisotropic etching of Si, and CF ₄ gas was used for dry etching.

The substances used for the electrodes, the sacrificial layer and the elastic layer are not limited to the above, and other substances can be used.

An example of the dimensions of the main part of the cantilever type displacement element manufactured in this example is shown below.

Height of raised portion 304: 280 μm Length of inclined portion of raised portion 304: 350 μm Length of cantilever 303: 360 μm Width of cantilever 303: 50 μm Despite being able to move away from the substrate surface, a displacement amount per drive voltage similar to that of the conventional element having the same cantilever size was obtained.

Example 9 FIG. 13 shows a cantilever probe of this example. FIG. 13A is a top view and FIG. 13B is FIG.
It is sectional drawing in dashed line AA 'in (a).

In addition to the structure of the eighth embodiment, the cantilever probe of the present embodiment additionally has a conductive probe 321 and a lead electrode 322 connected thereto at the tip of the cantilever.

The probe 321 has the extraction electrode 322.
Is formed by vapor deposition and photolithography, then photoresist is applied to a thickness of 5 μm, the resist is removed only at the position where the probe 321 is formed, an opening is formed, and it is formed by combining vacuum vapor deposition from a diagonal direction and substrate rotation. .
This method is known as a method for forming a microstructure having a high aspect ratio.

The cantilever type probe of this embodiment can be used as a probe of a scanning probe microscope. For example, a tunnel current that flows when the tip of the probe 321 is brought close to the surface of the conductive sample by about several nm is detected, and the drive voltage of the cantilever is fed back to the probe 32.
The distance between 1 and the sample surface can be kept constant. By scanning the cantilever in the in-plane direction of the sample by the external scanning means in such a state, it becomes possible to observe minute irregularities and conductivity distribution on the sample surface from changes in the feedback voltage.

In the cantilever type probe of this embodiment,
When the probe is brought closer to the sample surface, the restriction of the protrusion on the substrate surface is relaxed, and the probe can be brought closer to the sample surface more reliably.

Embodiment 10 In this embodiment, a plurality of cantilever type probes described in Embodiment 9 are manufactured on the same silicon substrate and integrated with a semiconductor element to form an integrated probe 330 as shown in FIG. It was made.

In FIG. 14, the same silicon substrate 301 is used.
Each of the cantilever type probes formed above is connected to the semiconductor element 331. Internal wiring 332 is connected to the semiconductor element 331, and input / output with the outside is possible through an external terminal 333.

Such an integrated probe is used in the above-mentioned embodiment 8,
In the manufacturing method described in 9, it can be manufactured only by expanding the photolithographic pattern. As described above, since a plurality of cantilevers can be formed on the same substrate at the same time, the dimensional accuracy is very high, and the variation in characteristics between the cantilevers can be suppressed to be very small.

Further, by using Si single crystal as the substrate, semiconductor elements such as transistors and diodes can be integrated on the same substrate, and an amplifier for tunnel current amplification and cantilever driving can be integrated. it can.

FIG. 15 is a diagram schematically showing an STM device using the integrated probe of this embodiment. This allows
By using the integrated probe 330, it is possible to simultaneously observe STM images of a plurality of minute regions on the surface of the observation target 353. In the figure, reference numerals 351 and 352 denote movable stages having a coarse movement mechanism in the X, Y, and Z directions. The integrated probe 330 is fixed to the movable stage 351, and the observation target 353 is fixed to the movable stage 352. .

Reference numeral 354 is a coarse movement mechanism in the Z direction.
Reference numerals 5,356 denote fine movement mechanisms in the XY directions. Reference numeral 357 is an adjustment mechanism for parallelizing the observation target 353 and the integrated probe 330. Reference numerals 358 and 359 denote computer systems for controlling the respective fine coarse movement mechanisms. Reference numeral 360 is a control device for detecting a tunnel current from each probe and feeding back the amount of displacement of the cantilever.

FIG. 16 shows the integrated probe 3 in FIG.
It is sectional drawing which expanded 30 and a part of observation target 353.

By using the cantilever type probe according to the present invention in such an STM system,
The degree of freedom in selecting the mounted elements has been greatly improved, and the difficulty in connecting to the outside and driving it has been reduced.

An example of the dimensions of the integrated probe manufactured in this example is shown below.

Outer diameter of integrated probe 330 ... 40 mm ×
40 mm × 1 mm Number of cantilevers… 90 Length of each cantilever… 500 μm Width of each cantilever… 50 μm Height of probe 321… 3 μm Example 11 FIG. 17: Information using the integrated probe described in Example 10 The schematic diagram of the information processing apparatus which can perform recording / playback of FIG.

In the figure, 373 is a recording layer whose resistance value is changed by applying a voltage, 372 is a metal electrode layer, and 371 is a recording medium substrate. 374 is an XY stage, 375 is an integrated probe according to the present invention, 376 is an integrated probe support, 377 is a linear actuator for coarsely moving the integrated probe in the Z direction, 378 and 379 are XY stages, respectively. A linear actuator 380 driven in the Y direction is a recording / reproducing bias circuit. Three
Reference numeral 81 is a tunnel current detector, 382 is a servo circuit for moving the integrated probe in the Z-axis direction, 383
Is a servo circuit for driving the actuator 377. Reference numeral 384 is a drive circuit for minutely displacing each cantilever, 385 is a drive circuit for the actuator 377, and 386 is a drive circuit for controlling the position of the XY stage. 387 is a computer that controls these operations.

By using such a system,
It is possible to record a large amount of information at a high density, and since a large number of probes are integrated and they are simultaneously scanned, high-speed recording / reproducing can be performed.

By using the third cantilever type displacement element of the present invention in such a system, the limitation of the element arranged on the substrate is relaxed, the tracking performance at the time of recording and reproducing is improved, and the error at the time of writing and reading is caused. The occurrence rate can be reduced.

Further, the cantilever type probe according to the third aspect of the present invention can be applied to the AFM, STM, processing apparatus, and their combined apparatus in the same manner as the cantilever type probe according to the first and second aspects of the present invention described above. You can On the other hand, the cantilever type probes according to the first and second aspects of the present invention can be applied to the information processing apparatus as described above, similarly to the cantilever type probe according to the third aspect of the present invention.

[0104]

As described above, the present invention has the following effects. (1) In the first cantilever type displacement element of the present invention, the sticking phenomenon is prevented without performing the manufacturing process using the sublimable material by providing the convex portion on the substrate surface or the surface of the cantilever on the substrate side. Therefore, the manufacturing process is simplified and the yield is improved. In addition, when the convex portion is formed of an insulating material, it is possible to avoid an electrical short circuit between the fixed electrode and the counter electrode even if the cantilever is largely displaced, and the durability of the element and its electrical control system is improved. Is improved, which in turn improves the durability of various devices equipped with this element. (2) The second cantilever type displacement element of the present invention can avoid an electrical short circuit between the fixed electrode and the counter electrode by a simple means by the shape of the insulating layer forming the cantilever, and cantilever type displacement element of the first aspect of the present invention. Like the displacement element, the durability of the element and various devices equipped with the element is improved. (3) In the third cantilever type displacement element of the present invention, since the substrate surface under the cantilever is raised and the fixed electrode is provided on the raised portion, the tip of the cantilever is placed on the substrate surface without lowering the displacement amount. Away from you,
The degree of freedom in the arrangement of elements and the wiring to the outside increases.

Further, in the scanning tunneling microscope and the information processing apparatus constructed by using this element, it is possible to avoid the contact between the sample or the recording medium and the element substrate, and to realize a more reliable apparatus.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of a cantilever type probe according to a first aspect of the present invention.

FIG. 2 is a diagram for explaining a manufacturing process of the cantilever type probe of FIG.

FIG. 3 is a schematic configuration diagram of a cantilever type probe according to a first embodiment of the present invention shown in a second embodiment.

FIG. 4 is a schematic configuration diagram of a cantilever probe according to a first embodiment of the present invention shown in a third embodiment.

FIG. 5 is a schematic configuration diagram of a cantilever type probe according to a first embodiment of the present invention shown in a fourth embodiment.

FIG. 6 is a schematic view of a scanning probe microscope incorporating a cantilever probe according to the first aspect of the present invention.

FIG. 7 is a schematic configuration diagram showing an example of a cantilever type probe according to a second aspect of the present invention.

FIG. 8 is a diagram for explaining a manufacturing process of the cantilever type probe of FIG.

FIG. 9 is a schematic configuration diagram of a cantilever type probe according to a second aspect of the present invention shown in Example 7.

FIG. 10 is a schematic view of an STM device incorporating a cantilever type probe according to the second aspect of the present invention.

FIG. 11 is a schematic configuration diagram of a third cantilever type displacement element of the present invention.

FIG. 12 is a diagram for explaining a manufacturing process of the cantilever displacement element in FIG. 11.

FIG. 13 is a schematic configuration diagram of a cantilever type probe according to a third aspect of the present invention shown in Example 9;

FIG. 14 is a schematic configuration diagram of an integrated probe according to a third aspect of the present invention shown in Example 10.

FIG. 15 is an STM incorporating the integrated probe of FIG.
It is a schematic diagram of an apparatus.

16 is a partially enlarged view of the STM device of FIG.

17 is a schematic diagram of an information processing apparatus incorporating the integrated probe of FIG.

FIG. 18 is a schematic configuration diagram of a conventional cantilever probe.

[Explanation of symbols]

 101 substrate 102 insulating film 103 fixed electrode 104 convex portion 105 void 106 cantilever also serving as counter electrode 107 insulating film 108 probe 109 sacrifice layer 110 protrusion 111 convex portion 112 fixed electrode wiring 113 extraction electrode 120 sample 121, 122 wiring 123 Capacitance detection unit (electrostatic drive unit) 124 Tunnel current detection unit 125, 126 Wiring 201 Substrate 202 Insulating layer 203 Fixed electrode 206 Counter electrode 207 Insulating layer 208 Probe 209 Sacrificial layer 213 Leading electrode 221 Counter electrode end 222 Fixed electrode end 223 Insulating layer end 231 Bias application power supply 232 Tunnel current amplification circuit 233 Cantilever drive driver 234 Cantilever type displacement element 235 Sample 236 XY direction fine movement mechanism 3 01 substrate 302 fixed part 303 cantilever 304 raised part 305 fixed electrode 306 counter electrode 311 resist pattern 312 electrode film 313 sacrificial layer film 314 sacrificial layer 315 elastic layer 321 probe 322 extraction electrode 330 integrated probe 331 semiconductor element 332 internal wiring 333 external Terminals 351 and 352 Movable stage 353 Observation target 354 Z direction coarse movement mechanism 355, 356 X and Y direction fine coarse movement mechanism 357 Adjustment mechanism 358,359 Computer system 360 Controller 371 Recording medium substrate 372 Metal electrode layer 373 Recording layer 374 XY Stage 375 Integrated probe 376 Support 377 Z-direction linear actuator 378 X-direction linear actuator 379 Y-direction linear actuator 380 Recording / playback bias circuit Road 381 Tunnel current detector 382,383 Servo circuit 384,385,386 Drive circuit 387 Computer 401 Si wafer 402 Fixed electrode 403 Si 404 Counter electrode 405 Cantilever 406 Insulation layer 407 Probe 408 Extraction electrode

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yasuhiro Shimada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yu Nakayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (14)

[Claims] 1. A cantilever type displacement element comprising a fixed electrode formed on a substrate and a cantilever provided on the substrate, the cantilever having a counter electrode facing the fixed electrode, the substrate and the cantilever. A cantilever-type displacement element having a convex portion between and on the surface of the substrate or on the surface of the cantilever on the substrate side. 2. The cantilever type displacement element according to claim 1, wherein the convex portion is provided in plural. 3. The cantilever type displacement element according to claim 1, wherein the convex portion is an insulator. 4. A cantilever-type displacement element comprising a fixed electrode formed on a substrate and a cantilever provided on the substrate, the cantilever having an opposed electrode facing the fixed electrode, wherein the cantilever is opposed to the cantilever. A cantilever-type displacement element, characterized in that an insulating layer protruding from the electrode toward the free end side is formed. 5. The cantilever type displacement element according to claim 4, wherein the fixed electrode is formed longer than the counter electrode in the free end direction of the cantilever. 6. The cantilever according to claim 4, wherein a distance between the insulating layer at the free end of the cantilever and the fixed electrode is shorter than a distance between the counter electrode and the fixed electrode. Mold displacement element. 7. A cantilever type provided with a fixed electrode formed on a raised portion of a substrate, and a cantilever provided on the substrate so as to have a counter electrode facing the fixed electrode and along the raised portion. Displacement element. 8. A cantilever type displacement element comprising a plurality of cantilever type displacement elements according to claim 1 formed on the same substrate. 9. The cantilever type displacement element according to claim 1, wherein a sharp probe is provided at a free end of the cantilever. 10. A cantilever type probe according to claim 9, wherein the probe is brought close to a sample surface for scanning,
And due to the electrostatic force between the fixed electrode and the counter electrode,
A scanning probe microscope that displaces the cantilever in a direction perpendicular to a scanning plane. 11. A cantilever type probe according to claim 9, wherein the probe is brought into contact with a sample surface for scanning,
A scanning probe microscope that detects displacement of the cantilever in a direction perpendicular to a scanning surface by detecting capacitance between the fixed electrode and the counter electrode. 12. A processing apparatus using the microscope configuration according to claim 10 or 11 for changing the characteristics of a sample surface. 13. A composite device comprising a plurality of microscopes or processing devices according to claim 10 as one device. 14. A cantilever type probe according to claim 9, wherein the probe is brought close to a recording medium, and a voltage is applied between the probe and the recording medium to record and / or reproduce information. Information processing device to perform.