JP2001001300A - Fine beam structure, and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fine beam structure which is strong against the repeated twist and excellent in durability, and its manufacturing method. SOLUTION: A sectional structure of a beam 2 to support a micro mirror 1 is a double structure in which a periphery of a Ti core 3 is covered by a Si layer 4. The sectional structure may be a double structure in which a periphery of a Si core is covered by a Ti layer. W, Mo, etc., may be used in place of Ti, and SiO2, SiNx, etc., may be used in place of Si. A metal silicide layer or a metal oxide layer may be formed on an interface between the core and the cover layer as a tightly adhered layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microbeam structure and a method of manufacturing the same, and more particularly, to a microelectromechanical system (MEMS).
It is suitable for use in a microbeam structure in the field of mechanical systems, for example, a microbeam structure that supports a fine mirror (micromirror).

[0002]

2. Description of the Related Art Conventionally, as a general micromirror in the field of MEMS, a structure in which a mirror portion is supported by a metal beam (beam) (for example, Japanese Patent Application Laid-Open No. 9-281417) and a mirror portion by a Si beam. (Eg, Journal of the Institute of Image Information and Television Engineers, Vol. 52, No. 10, pp. 1507-151)
2 (1988)).

[0003]

However, in the conventional structure in which the mirror is supported by a metal beam, if the beam is repeatedly twisted to vibrate the mirror at high speed, the beam portion is damaged by metal fatigue. There was a drawback to do.

Further, the conventional structure in which the mirror portion is supported by the Si beam has the following problem. First, the main resonance frequency ω of the mirror is ω = (K / I) ^1/2 (where,
K is the torsional rigidity and I is the moment of inertia)
K is proportional to Young's modulus E. The Young's modulus of Si is (1.3
1.9) × 10 ¹¹ (N · m ⁻² ), and the Young's modulus of Ti is 1.16 × 10 ¹¹ (N · m ⁻² ) and the Young's modulus of Au is 7.
Since it is considerably larger than 80 × 10 ¹⁰ (N · m ⁻² ), the main resonance frequency becomes larger than that of a metal beam of the same size, and the difference between the main resonance frequency desired to be used as an actual servo band and the secondary resonance frequency is obtained. There is a disadvantage that the interval (band) becomes narrow. Further, although Si has a high yield strength in a single crystal, it has a drawback that it is easily broken due to scratches or defects generated during the process due to its remarkable cleavage.

Accordingly, an object of the present invention is to provide a fine beam structure which is resistant to repeated torsion and has excellent durability and a method for manufacturing the same.

[0006]

In order to solve the above-mentioned problems, a first invention of the present invention is directed to a first portion and a second portion provided at least partially around the first portion. Wherein the first portion and the second portion are made of materials having different mechanical properties from each other.

In the first aspect of the present invention, the second portion is provided at least partially around the first portion. In general, is the second portion provided over the entire outer peripheral surface of the first portion? A plurality of the second portions may be provided on the entire outer peripheral surface of the first portion so as to be separated from each other in the circumferential direction. In one typical example, the first part comprises the core of the beam and the second part
Is provided so as to cover the periphery of the first portion. The material forming the first portion and the material forming the second portion have different mechanical properties from each other, but the selection of these materials can be made according to the characteristics required for the microbeam structure. it can. For example, in a microbeam structure that is subjected to repeated torsion, such as a beam that supports a micromirror, the material forming the first portion and the material forming the second portion have a low yield strength and low fracture resistance. At least one of them is different from each other. Specifically, for example, the yield strength of the material forming the second portion is superior to the yield strength of the material forming the first portion, and the yield strength of the material forming the first portion is reduced. The hardness is superior to the difficulty of the material constituting the second part being damaged. Alternatively, conversely, the yield strength of the material forming the first portion is
The material constituting the second portion is superior to the yield strength, and the material constituting the second portion is more difficult to break than the material constituting the first portion.
In addition to these mechanical properties, from the viewpoint of improving the mechanical strength by forming the microbeam structure from the first portion and the second portion made of different materials, the microbeam structure is twisted. It is important that there is no relative displacement between the first and second parts in the event that the first part and the second part are present. It is important to ensure the adhesion of
As a material forming the second portion and a material forming the second portion, a material capable of obtaining good adhesion can be selected, or the material forming the second portion can be formed at the interface between the first portion and the second portion. It is important to form an adhesion layer. In one typical example, one of the first portion and the second portion is made of a metal, and the other is made of silicon or a silicon compound.
Here, as the metal, for example, Ti, Cr, W, Mo, or the like can be used, and in the case of an application of flowing an electric current, Al or the like can also be used. The silicon compound is, for example, silicon oxide (SiO ₂ ) or silicon nitride (SiN _x ), and in some cases, silicon nitride oxide (SiON).

According to a second aspect of the present invention, a first portion and a second portion provided on at least a part of a periphery of the first portion are provided.
And wherein the first portion and the second portion are made of materials having different mechanical properties from each other, and the first portion and the second portion are made of the first material. Forming a groove in the layer; and forming a first layer on the layer of the first material.
Forming a layer made of a second material different from that of the second material so as to fill the groove, and removing a portion of the layer made of the second material other than the portion embedded inside the groove,
Forming a layer made of a third material different from the second material on the layer made of the first material; and forming the first material into a predetermined shape including the layer made of the second material embedded in the groove. Patterning a layer made of the third material and a layer made of the third material.

According to a third aspect of the present invention, there is provided a first portion and a second portion provided at least partially around the first portion.
And wherein the first portion and the second portion are made of materials having different mechanical properties from each other, and the first portion and the second portion are made of the first material. Forming a linear pattern made of a second material on the layer, and forming a layer made of a third material different from the second material on the layer made of the first material so as to cover the pattern And a step of patterning the layer made of the first material and the layer made of the third material into a predetermined shape including the pattern.

According to a fourth aspect of the present invention, a first portion and a second portion provided on at least a part of a periphery of the first portion are provided.
And wherein the first portion and the second portion are made of materials having different mechanical properties from each other, and the first portion and the second portion are made of the first material. The method includes a step of forming a linear pattern, and a step of forming a layer made of a second material around the pattern while rotating the pattern around its axis.

In the second and third aspects of the present invention, typically, one of the first material, the third material, and the second material is silicon or a silicon compound;
The other is metal. Further, from the viewpoint of improving the adhesion between the first portion and the second portion in the microbeam structure, an intermediate layer that enhances the adhesion at the interface between the first portion and the second portion, that is, It is desirable to form an adhesion layer. Specifically, for example, when one of the first material, the third material, and the second material is silicon and the other is metal, heat treatment is performed after forming at least a layer made of the third material. By doing so, the layer made of the first material and the third
A metal silicide layer is formed at the interface between the layer made of the second material and the layer made of the second material or the linear pattern. Alternatively, in the case where one of the first material, the third material, and the second material is silicon oxide and the other is metal, heat treatment is performed after forming a layer including at least the third material. A metal oxide layer is formed at the interface between the layer made of the first material and the layer made of the third material and the layer made of the second material or the linear pattern. With these metal silicide layers or metal oxide layers, the adhesion between the first portion and the second portion can be significantly improved.

Similarly, in a fourth aspect of the present invention,
Typically, one of the first material and the second material is silicon or a silicon compound, and the other is a metal. Further, from the viewpoint of improving the adhesion between the first portion and the second portion in the fine beam structure, it is desirable to form an adhesion layer at the interface between the first portion and the second portion. Specifically, for example, when one of the first material and the second material is silicon and the other is metal, the first material is formed by performing a heat treatment after forming a layer made of the second material. A metal silicide layer is formed at the interface between the linear pattern made of the material and the layer made of the second material. Alternatively, in the case where one of the first material and the second material is silicon oxide and the other is metal, a line made of the first material is formed by performing a heat treatment after forming a layer made of the second material. A metal oxide layer is formed at the interface between the shape pattern and the layer made of the second material. With these metal silicide layers or metal oxide layers, the adhesion between the first portion and the second portion can be significantly improved.

In the second, third and fourth aspects of the present invention, various methods such as a CVD method, a sputtering method, a vacuum evaporation method, and a plating method are used as a film forming method depending on a material to be formed. Can be used. For filling the groove, a method of forming a layer serving as a filling material and flattening the layer by chemical mechanical polishing (CMP) or etch back can be used. Further, for example, a dry etching method can be used for forming and patterning the groove.

The cross-sectional shape of the fine beam structure according to the present invention is selected according to the use of the fine beam structure and the like, and specific examples include a square, a rectangle, a circle, and an ellipse. The diameter of the fine beam structure is designed as required, but is generally, for example, 1 mm or less, typically 100 μm or less, more typically 50 μm.
m or less. Further, this fine beam structure may be basically used for supporting any supported body, but specifically, for example, is used as a beam for supporting a micro mirror.

According to the first aspect of the present invention configured as described above, a cross-sectional structure including a first portion and a second portion provided at least partially around the first portion. And the first portion and the second portion are made of materials having different mechanical properties from each other, so that, for example, the material forming one of the first portion and the second portion yields By using a material with excellent strength and using a material that is not easily broken in the material constituting the other, it is possible to make the overall fine beam structure excellent in yield strength and hard to break, and repeatedly And excellent durability can be obtained.

Further, according to the second, third and fourth aspects of the present invention configured as described above, it is possible to easily and accurately use established techniques such as a film forming technique and a patterning technique. A fine beam structure can be manufactured.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. In all the drawings of the embodiments, the same or corresponding portions are denoted by the same reference numerals.

FIG. 1 shows a micromirror beam structure according to a first embodiment of the present invention. FIG. 1A is a plan view (top view), and FIG. 1B is an enlarged sectional view taken along the line BB 'of FIG. 1A. FIG. 3 is an enlarged sectional view perpendicular to the axis of the beam.

As shown in FIG. 1A, this micromirror beam structure has a square planar shape of Si.
Both ends in one diagonal direction of the micro mirror 1 made of
It is supported by a narrow beam 2 extending in its diagonal direction. The beam 2 is fixed to an outer frame (not shown), and has a structure in which the micromirror 1 floats. The micromirror 1 is configured to vibrate around the beam 2 by twisting the beam 2 using a driving force such as an electrostatic force.

As shown in FIG. 1B, the beam 2 has a sectional structure in which the periphery of a Ti core material 3 is covered with a Si layer 4. The Si layer 4 may be any of single crystal, polycrystal, and amorphous. Here, the Si layer 4 is superior in yield strength to the Ti core material 3, and the Ti layer 3 is superior to the Si layer 4 in terms of resistance to breakage. Since the beam 2 has such a cross-sectional structure, the strength of the beam can be improved as compared with the case where the beam is composed of only a metal such as Ti, so that the phenomenon that the beam is broken due to metal fatigue is significantly reduced. Can be done. Further, the main resonance frequency can be reduced as compared with the case where the beam is constituted only by Si, and the interval (band) between the main resonance frequency desired to be used as the servo band and the secondary resonance frequency can be widened. At the same time, damage during the process can be reduced.

As described above, according to the first embodiment, the beam 2 supporting the micromirror 1 is made of the Ti core material 3.
Has a cross-sectional structure in which the periphery of the beam 2 is covered with the Si layer 4, so that the beam 2 is not only excellent in vibration characteristics, but also resistant to repeated torsion, hard to break, and excellent in durability. And a longer life can be achieved.

FIG. 2 shows a second embodiment of the present invention.
1 shows a method for manufacturing a micromirror beam structure according to a first embodiment. This manufacturing method utilizes a damascene (image fitting) method.

In this manufacturing method, as shown in FIG.
A groove 12 is formed by etching a predetermined portion of the surface of the Si layer 11 formed on the sacrificial layer (not shown) by a dry etching method. The cross-sectional shape of the groove 12 is
It has the same cross-sectional shape as the Ti core of the beam to be formed.

Next, as shown in FIG.
The Ti layer 13 is formed on the entire surface of the Si layer 11 by the
2 is buried in this Ti layer 13.

Next, as shown in FIG.
(Chemical Mechanical Polishing)
Polishing of the Ti layer 13 until the surface of the layer 11 is exposed,
Unnecessary Ti layer 13 is removed until the surface of Ti layer 13 filling trench 12 becomes the same height as the surface of Si layer 11.

Next, as shown in FIG.
An amorphous Si layer 14 is uniformly formed on the entire surface by a method. Next, the Si layer 1 is formed by photolithography.
After forming a resist pattern 15 having a planar shape in which a desired beam shape and a micromirror shape are combined on the resist pattern 4, the Si layer 14 and the Si layer 11 are etched by, for example, a dry etching method using the resist pattern 15 as a mask. To form a beam portion and a micromirror portion (not shown) made of Si.

Thereafter, the sacrifice layer under the Si layer 11 is removed by etching. This produces, as shown in FIG. 2E, a beam 2 having a double-sectioned cross-section that supports a floating micromirror portion, not shown. However, in FIG. 2E, the Ti
The layer 13 covers the Ti core material 3 and the S surrounding the Ti layer 13.
The i layers 11 and 14 are rewritten as the Si layer 4 respectively.

As described above, according to the second embodiment, the microbeam structure according to the first embodiment can be easily and highly accurately formed by using the established techniques such as a film forming technique and a patterning technique. Can be manufactured.

FIG. 3 shows a third embodiment of the present invention.
5 shows another method for manufacturing the micromirror beam structure according to the first embodiment.

In this manufacturing method, as shown in FIG.
After a Ti layer is formed on the Si layer 21 formed on the sacrificial layer (not shown) by, for example, a sputtering method, the Ti layer is linearly patterned by, for example, a dry etching method to form a Ti core material 22. .

Next, as shown in FIG.
A Si layer 23 is formed on the entire surface of the Si layer 21 so as to cover the Ti core material 22 by a method.

Next, as shown in FIG.
After the surface of the Si layer 23 is flattened by the method, a resist pattern 24 having a planar shape matching the desired beam shape and micromirror shape is formed on the Si layer 23 by photolithography.

Next, using the resist pattern 24 as a mask, the Si layer 23 and the S
By etching the i-layer 21, a beam portion and a micromirror portion (not shown) made of Si are formed.

Thereafter, the sacrificial layer under the Si layer 21 is removed by etching. This produces, as shown in FIG. 3D, a beam 2 having a double-sectioned cross-section that supports a floating micromirror portion, not shown. However, in FIG. 3D, the Ti core material 22
Are rewritten as the Ti core material 3, and the Si layers 21 and 23 covering the periphery of the Ti core material 22 as the Si layer 4.

According to the third embodiment, similarly to the second embodiment, the microbeam structure according to the first embodiment can be manufactured easily and with high precision.

FIG. 4 shows a fourth embodiment of the present invention.
1 shows a method for manufacturing a micromirror beam structure. In this micromirror beam structure, the core is made of Si, and its periphery is covered with a Ti layer.

In this manufacturing method, as shown in FIG.
First, a Si core material 31 having a square or rectangular cross-sectional shape serving as a core of a micromirror beam is formed. The Si core material 31 is connected to both ends of a micromirror (not shown) one by one. These Si core materials 31
The micromirrors are formed on a Si wafer (not shown), and the back surfaces thereof can be viewed from the back surface of the Si wafer by deep etching from the back surface of the Si wafer.

Next, as shown in FIG. 4B, the Ti particles 32 are blown off using, for example, a sputtering apparatus, and a Ti layer 33 is formed on the Si core material 31. At this time, by rotating the Si wafer so that the other side surface of the Si core material 31 is also directed to the direction in which the Ti particles 32 fly, as shown in FIG. As a result, the beam 2 having a structure in which the Si core material 31 is covered with the Ti layer 33 can be manufactured.

According to the fourth embodiment, the Si core material 3
A beam 2 having a cross-sectional structure in which the periphery of 1 is covered with a Ti layer 4 can be easily and accurately manufactured. According to the beam 2 having such a structure, the beam intensity can be improved as compared with the case where the beam is constituted only by a metal such as Ti, so that the phenomenon that the beam is broken due to metal fatigue is greatly reduced. be able to. Also, S
The main resonance frequency can be reduced as compared with the case where the beam is constituted only by i, and the interval (band) between the main resonance frequency to be used as the servo band and the secondary resonance frequency can be widened, Damage during the process can be significantly reduced.

FIG. 5 shows a fifth embodiment of the present invention.
In the fifth embodiment, the intensity of the beam 2 of the micro-mirror beam structure according to the first embodiment is further improved. That is, the micromirror beam structure shown in FIG. 1 is a strong structure that does not cause any problem in normal use, but has a micromirror beam structure that can be used even when the micromirror 1 is vibrated with a stronger force. Form.

In the fifth embodiment, first, as shown in FIG. 5A, a beam 2 having a structure similar to that of the first embodiment, that is, a structure in which the periphery of a Ti core material 3 is covered with a Si layer 4 is applied. To manufacture. As described above, the beam 2 is connected to both ends of a micromirror made of Si (not shown).

Next, as shown in FIG. 5B, the RTP (Rapi
d Thermal Process) The micromirror beam structure shown in FIG. 5A is placed in a device 41, and a two-stage annealing process is performed in, for example, a nitrogen atmosphere. By this annealing treatment, as shown in FIG. 5C, a Ti silicide layer 42 is formed at the interface between the Ti core material 3 and the Si layer 4 by their reaction. The Ti core material 3 is formed by the Ti silicide layer 42.
And the Si layer 4 are firmly adhered to each other.

As described above, according to the fifth embodiment, since the Ti silicide layer 42 is formed at the interface between the Ti core 3 and the Si layer 4, the Ti core 3 and the Si layer 4 , The micromirror 1 can be driven with a stronger force, and can be more resistant to repeated vibrations.

Next, the first, second, third and fourth embodiments of the present invention will be described.
An example of the fifth embodiment will be described.

Example 1 Example of First Embodiment A micromirror 1 shown in FIG. 1A has a length of 300 μm and a width of 3 μm.
It is made of Si having a thickness of 00 μm and a thickness of 50 μm. Although not shown, Au is deposited on the mirror surface of the micro mirror 1. Both ends of the micromirror 1 have a length of 50 μm.
A beam 2 having an m, a width of 15 μm, and a thickness of 15 μm is attached. The beam 2 is fixed to an outer frame (not shown), and the micromirror 1 is supported by the beam 2 and floats. Micro mirror 1
Of the beam 2 with the electrostatic force between the back surface of the micromirror 1 and an electrode (not shown), which is opposed to the back surface of the micromirror 1 via an air gap of 5 μm, as a driving force.
In the twisting mode.

In the cross section of the beam 2 shown in FIG.
The i-core 3 has a length of 8 μm and a width of 8 μm, and the thickness of the Si layer 4 around the Ti core 3 is 3.5 μm.

By employing this micromirror beam structure, it was possible to realize a practical micromirror utilizing the characteristics of tough Ti and resistant to metal fatigue.

Example 2 Example of the Second Embodiment A 10 μm thick SiO as a sacrificial layer not shown
_A 13 μm thick Si layer 11 was formed on the _two films. This S
The width of 12 μm and the depth of 8 μm are applied to the i-layer 11 by dry etching.
A groove 12 having a depth of m and a depth of 60 μm was formed. Then, CV
A 14 μm-thick Ti layer 13 was formed by method D, and the groove 12 was filled. Actually, a part of the Ti layer 13 on the groove 12 is slightly recessed. An electrode structure for driving a mirror has already been formed on a Si wafer (not shown) below the sacrificial layer.

Next, the extra Ti layer 13 was removed by CMP until the surface of the underlying Si layer 11 was exposed.
As a result, the surface of the Ti layer 13 filling the groove 12 was at the same height as the surface of the Si layer 11. In this state, C
The amorphous Si layer 14 is formed to a thickness of 5 μm using the VD method.
A uniform film was formed on the entire surface.

Next, a resist pattern 15 having a shape matching the shape of the micromirror and the beam is formed on the Si layer 14 by photolithography, and the Si layer 14 is dry-etched using the resist pattern 15 as a mask. 14 and the Si layer 11 were patterned. At this time, an underlying sacrificial layer SiO not shown
_{The two} membranes act as stoppers. The cross-sectional dimensions of the beam 2 to be formed were 18 μm in length and 22 μm in width, and the depth (length of the beam 2) was 60 μm. By this dry etching, a micromirror portion made of Si is also formed at the same time.

Next, the Si of the sacrificial layer below the Si layer 11
By removing the O ₂ film by wet etching with HF, a beam 2 having a double structure supporting a floating micromirror portion (not shown) could be manufactured.

Example 3 Example of Third Embodiment A 10 μm thick SiO as a sacrificial layer not shown
An amorphous Si layer 21 having a thickness of 5 μm is formed on the _two films. An 8 μm thick Ti layer is formed on the Si layer 21 by a sputtering method. The Ti layer was patterned by dry etching using photolithography to form a Ti core material 22 having a cross-sectional dimension of 8 μm, a width of 12 μm, and a depth (length) of 60 μm. An electrode structure for driving a mirror has already been formed on a Si wafer (not shown) below the sacrificial layer.

Next, the amorphous Si layer 2 is formed by the CVD method.
3 was formed to a thickness of 20 μm, and the Ti core material 22 was completely embedded. In this state, the portion of the Si layer 2 on the Ti core material 22
3 has a protrusion.

Subsequently, the Si layer 23 was polished by using the CMP method, the protrusions on the Ti core material 22 were removed, and the extra Si layer 23 was removed until the surface of the Si layer 23 became flat. At this time, the thickness of the Si layer 23 on the Ti core material 22 is 5
μm.

Next, a resist pattern 24 having a shape matching the shape of the micromirror and the beam is formed on the Si layer 23 by photolithography, and the Si layer 23 is formed by dry etching using the resist pattern 24 as a mask. 23 and the Si layer 21 were patterned. At this time, an underlying sacrificial layer SiO not shown
_{The two} membranes act as stoppers. The cross-sectional dimensions of the beam 2 to be formed were 18 μm in length and 22 μm in width, and the depth (length of the beam 2) was 60 μm. By this dry etching, a micromirror portion made of Si is also formed at the same time.

Next, the sacrificial layer Si under the Si layer 21
By removing the O ₂ film by wet etching with HF, a beam 2 having a double structure supporting a floating micromirror portion (not shown) could be formed.

Example 4 Example of Fourth Embodiment FIG. 4A is a cross section of a Si core material 31 serving as a core of a micromirror manufactured on a not-shown Si wafer. The cross-sectional dimensions of the Si core material 31 are 8 μm long and 12 μm wide.
m and depth (length) 50 μm. This Si core material 3
Numerals 1 are connected to both ends of a micromirror (not shown) one by one. The back side of the micromirror and the Si core material 31 can be seen from the back surface of the Si wafer by deep etching from the back surface of the Si wafer.

Next, the Si wafer was placed in a sputtering apparatus (not shown), and a Ti layer was formed under a pressure of 200 mTorr. At this time, a Ti layer 33 is formed on the surface of the Si core material 31 facing the direction in which the Ti particles 32 fly. Therefore, the Si core material 31 was continuously rotated about its axis in the direction of the arrow in FIG. 5B. Si core material 3
Since the back surface of 1 was visible from the back surface of the Si wafer, the Ti layer 33 was also formed on the back surface of the Si core material 31. In addition, a photoresist is coated on a place where the Ti layer 33 is not desired to be formed, thereby preventing the Ti layer 33 from adhering.

By continuing the rotation, the Si core material 3
A Ti layer 33 having a thickness of about 4 μm was formed around the substrate 1. Thus, the Si core material 31 covered with the Ti layer 33
A double-layered micromirror beam structure was obtained.

Example 5 Example of Fifth Embodiment FIG. 5A shows a cross section of a micromirror beam structure. The beam 2 has a length of 50 μm, a width of 15 μm, and a thickness of 15 μm. The Ti core material 3 in the cross-sectional structure of the beam 2 has a length of 8 μm and a width of 8 μm, and its periphery is covered with a 3.5 μm-thick Si layer 4. In this state, Au has not yet been deposited on the mirror surface of the micromirror,
Other than that, it is the same as the micro mirror beam structure shown in FIG.

First, the micro-mirror beam structure was placed in the RTP device 41 and replaced with a nitrogen atmosphere. And
The first stage annealing was performed by lamp annealing at 500 ° C. for 2 minutes, and the second stage annealing was performed by 750 ° C. for 2 minutes. By this two-step annealing process,
The interface between the Ti core material 3 and the Si layer 4 covering the Ti core material is Ti
The silicide (TiSi ₂ ) layer 42 was formed, and the adhesion between the Ti core material 3 and the Si layer 4 was further strengthened.

Subsequently, Au was vapor-deposited on the mirror surface of the micromirror portion (not shown) to complete the micromirror.

[0063]

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications based on the technical concept of the present invention are possible.

That is, the first, second, third, fourth
And the numerical values, structures, shapes, materials, film forming methods, processes, and the like described in the fifth embodiment are merely examples, and different numerical values, structures, shapes,
It is also possible to use materials, film formation methods, processes, and the like.

For example, in the first embodiment described above,
It is possible to use a W core material instead of the Ti core material 3 or use a SiO ₂ layer or a SiN _x layer instead of the Si layer 4.

In the second embodiment described above,
After the Ti layer 13 is embedded in the groove 12 of the Si layer 11, the amorphous Si layer 14 is formed.
Instead of forming 4, it is also possible to adopt a method of bonding single crystal Si substrates using anodic bonding.

In the fifth embodiment described above,
It was a Ti silicide layer 42 on their interface due to the adhesion improvement of the Ti core material 3 and the Si layer 4 comparison, for example, when using an SiO ₂ layer as a coating material, the metal core member When Cr, W, Mo, or the like, which is easily oxidized, is used, a metal oxide is generated at the interface between the SiO ₂ layer and the metal core material by the heat treatment, so that the adhesion between the core material and the coating material is similarly improved. Can be achieved.

Furthermore, in the above-described first, second, third, fourth and fifth embodiments, the beam 2 having a double structure has been described. It may be.

[0069]

As described above, according to the fine beam structure of the present invention, the cross-sectional structure including the first portion and the second portion provided at least partially around the first portion. Since the first portion and the second portion are made of materials having different mechanical properties from each other, it is possible to obtain a fine beam structure that is resistant to repeated twisting and has excellent durability.

Further, according to the method for manufacturing a fine beam structure according to the present invention, such a fine beam structure can be manufactured easily and with high accuracy.

[Brief description of the drawings]

FIGS. 1A and 1B are a plan view and an enlarged sectional view showing a micromirror beam structure according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining a method for manufacturing a micromirror beam structure according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view for explaining a method for manufacturing a micromirror beam structure according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view for explaining a method for manufacturing a micromirror beam structure according to a fourth embodiment of the present invention.

FIG. 5 is a cross-sectional view for explaining a method for manufacturing a micromirror beam structure according to a fifth embodiment of the present invention.

[Explanation of symbols]

1 ... micromirror, 2 ... beam, 3, 22 ・
..Ti core material, 4, 11, 14, 21, 23... Si
Layer, 12 groove, 31 core material, 32 T
i-particle, 33 ... Ti layer

Claims (20)

[Claims] 1. A sectional structure including a first portion and a second portion provided at least partially around the first portion, wherein the first portion, the second portion and Characterized in that they are made of materials having different mechanical properties from each other. 2. The method according to claim 1, wherein the first portion forms a core of the beam, and the second portion is provided so as to cover a periphery of the first portion. Fine beam structure. 3. The material forming the first portion and the material forming the second portion are different from each other in at least one of yield strength and resistance to breakage. Fine beam structure. 4. The material constituting the second portion has a higher yield strength than the material constituting the first portion, and the material constituting the first portion is damaged. 2. The microbeam structure according to claim 1, wherein the difficulty in breaking the material is higher than the difficulty in breaking the material of the second portion. 5. The yield strength of the material forming the first portion is higher than the yield strength of the material forming the second portion, and the material forming the second portion may be damaged. 2. The microbeam structure according to claim 1, wherein the difficulty in breaking the first member is higher than the difficulty in breaking the material constituting the first portion. 6. The microbeam structure according to claim 1, wherein one of the first portion and the second portion is made of a metal, and the other is made of silicon or a silicon compound. 7. The microbeam structure according to claim 6, wherein said silicon compound is silicon oxide or silicon nitride. 8. The micro beam structure according to claim 1, wherein the micro beam structure is for supporting a micro mirror. 9. A sectional structure including a first portion and a second portion provided at least partially around the first portion, wherein the first portion, the second portion and Forming a groove in a layer made of a first material, comprising: forming a groove in a layer made of a first material; Forming a layer made of a second material different from the first material so as to fill the groove, and removing a part of the layer made of the second material other than a part buried inside the groove; Forming a layer made of a third material different from the second material on the layer made of the first material; and forming a layer made of the second material embedded in the groove. A layer made of the first material and a layer made of the third material are included in a predetermined shape to be included. And a step of patterning a layer. 10. The microbeam according to claim 9, wherein one of the first material, the third material, and the second material is silicon or a silicon compound, and the other is a metal. The method of manufacturing the structure. 11. One of the first material, the third material, and the second material is silicon, and the other is metal, and is heat-treated after forming at least a layer made of the third material. Performing a step of forming a metal silicide layer at an interface between the layer made of the first material and the layer made of the third material and the layer made of the second material. 10. The method for manufacturing a microbeam structure according to item 9. 12. One of the first material, the third material, and the second material is silicon oxide, and the other is metal, and is formed after forming at least a layer made of the third material. By performing heat treatment, a metal oxide layer is formed at an interface between the layer made of the first material and the layer made of the third material and the layer made of the second material. A method for manufacturing a fine beam structure according to claim 9. 13. A sectional structure including a first portion and a second portion provided at least partially around the first portion, wherein the first portion, the second portion, Is a method of manufacturing a fine beam structure made of materials having different mechanical properties from each other, comprising: forming a linear pattern made of a second material on a layer made of a first material; Forming a layer made of a third material different from the second material on the layer made of the first material so as to cover the pattern; and a layer made of the first material in a predetermined shape including the pattern. And a step of patterning the layer made of the third material. 14. The microbeam according to claim 13, wherein one of the first material, the third material, and the second material is silicon or a silicon compound, and the other is a metal. The method of manufacturing the structure. 15. A heat treatment after one of the first material, the third material, and the second material is silicon, and the other is metal, after forming at least a layer made of the third material. 14. The microbeam structure according to claim 13, wherein a metal silicide layer is formed at an interface between the layer made of the first material, the layer made of the third material, and the pattern by performing the following. Manufacturing method. 16. One of the first material, the third material, and the second material is silicon oxide, and the other is metal, and is formed after forming at least a layer made of the third material. 14. The microstructure according to claim 13, wherein a metal oxide layer is formed at an interface between the layer made of the first material and the layer made of the third material and the pattern by performing a heat treatment. Manufacturing method of beam structure. 17. A sectional structure including a first portion and a second portion provided at least partially around the first portion, wherein the first portion, the second portion and Is a method of manufacturing a fine beam structure made of materials having different mechanical properties from each other, wherein a step of forming a linear pattern made of a first material is performed while rotating the pattern around its axis. Forming a layer made of a second material around the periphery thereof. 18. The method according to claim 17, wherein one of the first material and the second material is silicon or a silicon compound, and the other is a metal. 19. One of the first material and the second material is silicon, and the other is metal, and the heat treatment is performed after forming a layer made of the second material, thereby forming the pattern and the second material. The method according to claim 17, wherein a metal silicide layer is formed at an interface with the layer made of the second material. 20. One of the first material and the second material is silicon oxide, and the other is metal. The pattern is formed by performing a heat treatment after forming a layer made of the second material. 18. The method according to claim 17, wherein a metal oxide layer is formed at an interface between the layer and the layer made of the second material.