JPH10214978A - Semiconductor micromachine and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor micromachine in which dispersion in its characteristic is small and to provide its manufacturing method. SOLUTION: A semiconductor micromachine is provided with a substrate 12 and with a movable part 13 which is arranged so as to face the substrate 12 by keeping a gap part and which is supported by needlelike bodies 15. The moving part 13 is composed of a polycrystal Si thin film. The needlelike bodies 15 are composed of a polycrystal Si thin film constituted of crystal particles whose particle size is larger than that of the polycrystal Si thin film constituting the moving part 13. In addition, when the moving part 13 and the needlelike bodies 15 are formed, an Si thin film is formed on a substrate material on the side of the moving part and on a substrate material on the side of the needlelike bodies.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor micromachine that can be used for various kinds of microsensors and the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a micromachining technology using a semiconductor material such as silicon has been developed as a technology for producing an angular velocity sensor (gyro sensor), an acceleration sensor (G sensor), a microactuator, and the like having a small size. I have. According to this technique, it is possible to create the above-described sensor or the like as small as 1 mm or less by combining the techniques for creating a normal semiconductor circuit or the like. As an example of a product created by such a technique, there is a semiconductor micromachine that functions as an angular velocity sensor as described below.

As shown in FIG. 1 to be described later, the semiconductor micromachine 1 includes a substrate 12, a movable portion 13 which is disposed to face the substrate 12 with a gap provided therebetween, and which is supported by a needle-like body 15. It comprises a pair of fixed parts 17 arranged opposite to each other with the movable part 13 interposed therebetween. The movable part 13 is arranged so as to be parallel to the substrate 12. The movable section 13 has a driving electrode section 161 provided integrally on both sides thereof.

As shown in FIG. 3B described later, a distance detecting electrode 18 for detecting a distance from the movable portion 13 is provided on a surface of the substrate 12 facing the movable portion 13. . Further, the movable portion 13 is provided with a detection electrode portion 162 that operates in pairs with the distance detection electrode 18. The capacitance of the distance detection electrode 18 and the capacitor formed by the detection electrode 162 is provided. Is detected, the distance between the movable portion 13 and the substrate 12 is detected.

[0005] The fixed part 17 is provided with the movable part 1.
A fixed-part-side driving electrode part 171 for vibrating 3 is provided. The fixed portion side drive electrode portion 171 and the drive electrode portion 161 are arranged so as to engage with each other, and a fine gap 178 is formed between the two.

In the semiconductor micromachine 1, the angular velocity is detected as described below. First, the fixed portion side drive electrode portion 171 and the drive electrode portion 161
A periodic voltage is applied in between. As a result, horizontal vibration in the direction parallel to the substrate 12 is generated in the movable portion 13.

[0007] A rotational motion having an angular velocity ω is applied to the semiconductor micromachine 1 in this state in the direction of the rotation axis shown in FIG. As a result, a vibration is generated in the movable portion 13 in a direction perpendicular to the substrate 12 due to the Coriolis force. Note that between the horizontal vibration and the vertical vibration, F = 2 mωv (where F is the Coriolis force, m is the mass of the movable portion, and v is the speed of the horizontal movable portion). The relationship is established, and the vibration in the vertical direction is determined by the state of the horizontal vibration.

[0008] Due to the vertical vibration of the movable part 13, the distance of the gap between the movable part 13 and the substrate 12 changes according to the period of the vibration. By the way, the detection electrode section 1
62 is electrically connected to the needle 15 and the electrode pad 158, and the electrode pad 158 is grounded.
Therefore, the detection electrode section 162 is always kept at 0V.

The distance detecting electrode 18 and the detecting electrode portion 162 form a capacitor, and the capacitance is inversely proportional to the distance between the electrodes. Therefore, the distance detection electrode 1
By applying a constant voltage to the electrode 8, the change in the distance of the gap is detected by the detection electrode 162 and the distance detection electrode 1.
8 can be detected as a value of the variation of the electric charge stored in the capacitor composed of.

Conventionally, such a semiconductor micromachine 1 has been manufactured by using a normal semiconductor circuit manufacturing technique as shown below. That is, FIG.
As shown in FIG. 5, a substrate 12 in which the above-described distance detecting electrode 18 and the like have been prepared in advance by doping an n-type dopant on the p-type substrate 12 is prepared. Then, the substrate 1
2, an etching stopper layer 54 is provided on the surface, and an etching layer 55 is further provided on the surface thereof.

Next, a resist pattern is formed by a photolithography process, and using this as a mask, RIE (reactive ion etching, reactive ion etching) is performed.
ng), the etching layer 55 and the etching stopper layer 54 are etched to form a contact hole between the needle-like body 15 and the substrate 12.

Next, a polycrystalline Si-based thin film 57 is provided on the surface of the etching layer 55, and phosphorus as a dopant is doped by ion implantation. Thereafter, a heat treatment is performed on the polycrystalline Si-based thin film 57 for the purpose of activating the dopant and relaxing internal stress. The above polycrystalline Si
Instead of the system thin film, an amorphous Si system thin film can be used.

Then, the polycrystalline Si-based thin film 57 subjected to the heat treatment is etched into a predetermined shape by a photolithography process and RIE. As a result, portions that become the movable portion 13, the needle-like body 15, and the fixed portion 17 are created.

Next, the etching layer 55 in the lower part of the movable part 13 and the needle-like body 15 and in the vicinity thereof is removed (see FIGS. 2 and 4 to be described later). Thereafter, the movable portion 13, the fixed portion 17, and the distance detecting electrode 18
A semiconductor micromachine 1 is provided by appropriately providing an electrode pad for voltage application. Although omitted in the above process,
The wiring connecting each electrode and each electrode pad uses an n-type doped region with respect to a p-type substrate, a Si-based thin film 57,
Separate wiring may be provided.

[0015]

However, the conventional semiconductor micromachine described above has the following problems.
That is, both the needle-like body 15 and the movable part 13 are formed of a polycrystalline (or amorphous) Si-based thin film. By the way, generally, mechanical properties such as strength of a single crystal material are
It is determined by the size and shape of the substance. However, mechanical properties such as strength of a polycrystalline or amorphous substance cannot be uniquely determined. It takes a value that varies depending on various conditions, environment, and the like when producing the polycrystalline or amorphous substance.

Therefore, when the needle-like body 15 is formed of a polycrystalline or amorphous Si-based thin film, mechanical factors such as strength due to slight differences in the environment and manufacturing conditions during the manufacturing process are caused. The characteristics will vary.

In the semiconductor micromachine 1, the needle 15 supports the movable portion 13 and
This is an important part that determines the state of vibration of the movable part 13.
For this reason, the needle-like body 15 is required to have little variation in mechanical properties such as strength. This is because the mechanical characteristics of the needle-like body 15 change, so that the spring constant and the like of the needle-like body 15 also change. As described above, the characteristics of a conventional semiconductor micromachine having a needle-shaped body made of a polycrystalline (or amorphous) Si-based thin film have large variations.

Among the semiconductor micromachines having such variations, especially in the semiconductor micromachine acting as the above-mentioned angular velocity sensor, the detected angular velocity value becomes inaccurate. This problem also occurs in a semiconductor micromachine functioning as a microactuator, for example.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a semiconductor micromachine and a method of manufacturing the same, which have less variation in characteristics.

[0020]

According to a first aspect of the present invention, there is provided a semiconductor micromachine having a substrate and a movable portion which is provided to face the substrate with a gap provided therebetween and which is supported by a needle-like body. Crystalline Si-based thin film or amorphous Si
The acicular body is made of a single-crystal Si-based thin film, or the movable part is made of an amorphous Si-based thin film,
The needle-like body is made of a polycrystalline Si-based thin film, or both the movable part and the needle-like body are made of a polycrystalline Si-based thin film, and the needle-like body is made of a polycrystalline silicon constituting the movable part.
There is provided a semiconductor micromachine comprising a polycrystalline Si-based thin film composed of crystal grains having a larger particle diameter than the i-based thin film.

The operation of the present invention will be described below. In the semiconductor micromachine according to the present invention, the movable portion is made of a polycrystalline Si-based thin film or an amorphous Si-based thin film, and the needle is made of a single-crystal Si-based thin film. Or
The movable part is made of an amorphous Si-based thin film, and the needle-like body is made of a polycrystalline Si thin film.

Alternatively, the movable part is made of a polycrystalline Si-based thin film, and the needle-like body is made of polycrystalline Si constituting the movable part.
It is composed of a polycrystalline Si-based thin film composed of crystal grains having a larger particle diameter than the system-based thin film. That is, the needle-shaped body according to the present invention is made of a Si-based thin film having a crystal structure closer to a single-crystal Si-based thin film than the polycrystalline Si-based thin film or the amorphous Si-based thin film constituting the movable portion.

Since the mechanical properties of a single-crystal substance depend on the size and shape of the crystal, the mechanical properties of the single-crystal Si thin film having substantially the same size and shape vary between needles. Almost no. Even if the crystal grains are not perfect single crystals, but the crystal grains are large to some extent, that is, a needle-like body made of a polycrystalline Si-based thin film having crystal grains large enough to be regarded as a single crystal, There is almost no variation in the characteristic.

Further, when the grain size of the crystal grains in the needle-shaped body is particularly larger than the grain size of the crystal grains in the movable portion, the discontinuous plane of the crystal is small in the needle-shaped body acting as a spring. Uncertainties in mechanical properties are reduced. That is, variation in mechanical characteristics is reduced.

The needle-like body is an important part that supports the movable part and determines the state of vibration of the movable part. As described above, in the semiconductor micromachine according to the present invention, there is almost no variation in the mechanical characteristics of the needle-shaped body. Therefore, there is almost no variation in the spring constant of the needle-like body (that is, the parameter that most affects the state of vibration of the movable portion). For this reason, the semiconductor micromachine according to the present invention is an excellent semiconductor micromachine with small variations in its characteristics.

Therefore, when the semiconductor micromachine functions as an angular velocity sensor as shown in the prior art and the embodiment, since there is almost no variation in the spring constant of the needle-like body, There is almost no variation in horizontal vibration. Therefore, the angular velocity can be accurately detected. Also, when the semiconductor micromachine is an acceleration sensor or the like, the needle can act as a spring against a force acting in the vertical direction, so that the acceleration can be detected with high accuracy.

Also, when the semiconductor micromachine is a microactuator, the needle-like body acts as a spring supporting the movable part, so that the effect of reducing the variation in operation can be obtained.

As described above, according to the present invention, it is possible to provide a semiconductor micromachine having less variation in characteristics.

As the Si-based thin film, for example,
Si consisting called group IV semiconductor, Ge, Si _x Ge
_1-x, C _{(diamond), SiC, Si x Ge y} C
Thin films such as _(1-xy) and Ge _x C _1-x can be used.

Further, as the substrate, a single crystal silicon substrate, a polycrystalline silicon substrate, a glass substrate, a single crystal sapphire substrate, a stainless steel substrate or the like can be used. Since the single crystal silicon substrate is easily available, the productivity of the semiconductor micromachine can be increased. Further, the manufacturing process of a semiconductor micromachine can be used together with a normal LSI manufacturing process.

The above-mentioned polycrystalline silicon substrate can be obtained at low cost. Therefore, the manufacturing cost of the semiconductor micromachine can be reduced. In addition, since the above glass substrate is an inexpensive and easily available material,
The manufacturing cost of the semiconductor micromachine can be reduced.

Next, a second aspect of the present invention is a semiconductor micromachine having a substrate and a movable portion which is disposed opposite to the substrate with a gap provided therebetween and supported by a needle-like body. Is a polycrystalline Si-based thin film or amorphous Si
The acicular body is made of a single-crystal Si-based thin film, or the movable part is made of an amorphous Si-based thin film,
The needle-like body is made of a polycrystalline Si-based thin film, or both the movable part and the needle-like body are made of a polycrystalline Si-based thin film, and the needle-like body is made of a polycrystalline silicon constituting the movable part.
In manufacturing a semiconductor micromachine characterized by comprising a polycrystalline Si-based thin film composed of crystal grains having a grain size larger than that of the i-based thin film, first, in preparing the movable part and the needle-like body, first, On the substrate, a movable portion-side base material for forming a Si-based thin film serving as a movable portion and a needle-shaped body-side base material for forming a Si-based thin film serving as a needle-like body are formed. An Si-based thin film is formed on the surfaces of the movable portion-side base material and the needle-shaped body-side base material, and in an initial stage of the formation of the Si-based thin film, the nucleus density of the movable portion-side base material is the needle-like shape. The nucleus density of the body-side base material is kept higher than that of the body-side base material, and then the Si-based thin film is processed into the shape of the movable part and the needle-like body. And remove the above gap In a method of manufacturing a semiconductor micromachine which is characterized in that formed.

In the above manufacturing method, the substrate is provided with a movable portion-side base material for forming a Si-based thin film serving as a movable portion and a needle-shaped body-side base material for forming a needle-shaped Si-based thin film. In this case, a Si-based thin film is formed under the following conditions. Here, the condition is that in the initial stage of the formation of the Si-based thin film, the nucleus density of the movable portion-side base material is maintained higher than the nucleus density of the needle-shaped body-side base material.

By the way, as shown in FIG. 8 to be described later, in the portion where the crystal nucleus density is higher, that is, in the portion where the nucleus density is higher, the crystal grain grows too large because the distance between the crystal nuclei is short. Can not. On the other hand, in a portion where the density of crystal nuclei is low, that is, in a portion where the nucleus density is low, there is a sufficient distance between the crystal nuclei, so that the crystal grains can grow sufficiently. From these facts, according to the present invention, the crystal grains of the needle-shaped body can be made larger than the crystal grains of the movable part.

For this reason, as described in claim 1, the needle-like body is replaced with a polycrystalline S
Single-crystal S than i-based thin film or amorphous Si-based thin film
It can be composed of a Si-based thin film having a crystal structure close to the i-based thin film. Therefore, it is possible to obtain a semiconductor micromachine having almost no variation in mechanical characteristics of the needle-like body.

As described above, according to the present invention, it is possible to provide a method for manufacturing a semiconductor micromachine having less variation in characteristics.

As the movable portion base material, for example, a material in which an SiO ₂ film, a SiN film, or the like is formed on the surface of an etching layer that can be removed by an etching solution can be used. Also, as the needle-shaped base material, an etching layer which can be removed by an etching solution can be used.

In this case, as the etching layer, phosphor glass, arsenic glass, SiO ₂ or the like can be used. Further, as the etching solution, hydrofluoric acid, buffered hydrofluoric acid, or the like can be used. Further, it is preferable that the etching layer below the movable part and the etching layer below the needle-like body are formed of the same etching layer (FIGS. 6A-1 and 6A-2). reference).

Next, according to the third aspect of the present invention, the Si
When forming a system-based thin film, Si
H _4, GeH _4, it is preferable to use at least one selected from CH _4. The Si-based thin film formed by the source gas becomes a semiconductor thin film made of a group IV semiconductor.
For this reason, the same impurity used for controlling the conductivity of normal single-crystal Si can be used as the impurity for controlling the conductivity of the Si-based thin film. Therefore, an electrode or a wiring can be easily formed in the movable portion.

Next, as in the fourth aspect of the present invention, the needle-like body-side base material is more Si ₃ N ₄ >SiN>SiON> SiO 2 than the material selected as the movable part-side base material.
₂ > BSG (boron glass)> PSG (phosphorus glass)>
It is preferable to select a lower material in the order of BPSG (borophosphosilicate glass).
That is, for example, if you select the SiO ₂ as a movable side base material, a needle-like side base material, lower BS than
Select G, PSG, or BPSG.

Since the above inequality indicates the ease of forming crystal grains, it is possible to lower the nucleus density of the acicular body-side base material. Further, by forming the needle-shaped body-side base material and the movable part-side base material with the substance as described in the present claim, the size of the crystal grains on the needle-shaped body can be naturally reduced without performing other processing and operations. Can be bigger.

According to a fifth aspect of the present invention, there is provided a semiconductor micromachine having a substrate and a movable portion which is disposed to face the substrate with a gap therebetween and is supported by a needle-like body. Polycrystalline Si-based thin film or amorphous Si
The acicular body is made of a single-crystal Si-based thin film, or the movable part is made of an amorphous Si-based thin film,
The needle-like body is made of a polycrystalline Si-based thin film, or both the movable part and the needle-like body are made of a polycrystalline Si-based thin film, and the needle-like body is made of a polycrystalline silicon constituting the movable part.
In manufacturing a semiconductor micromachine characterized by comprising a polycrystalline Si-based thin film composed of crystal grains having a grain size larger than that of the i-based thin film, first, in preparing the movable part and the needle-like body, first, A base material is formed on the substrate, a Si-based thin film is formed on the base material, and then the Si-based thin film is processed into the shape of the movable part and the needle-like body. A method for manufacturing a semiconductor micromachine characterized by selectively heating a Si-based thin film in a body portion, removing the base material, and forming the gap.

The Si-based thin film can be formed by a CVD method, a sputtering method, or a vapor deposition method. Next, the S
The doping of the i-based thin film may be performed simultaneously with the formation of the Si-based thin film.
Doping can also be performed by means such as ion implantation, solid phase diffusion, and gas phase diffusion. As the selective heating, a method of selectively heating only the Si-based thin film in a portion to be a needle-like body or a method of heating the Si-based thin film in the portion to be a needle-like body to at least a portion to be a movable portion And heating at a higher temperature than the Si-based thin film.

In the manufacturing method according to the present invention, the needle-like body and the movable portion are formed from the same Si-based thin film, and the Si-based thin film in the portion to be the needle-like body is selectively heated. Become. In the crystal grains of the Si-based thin film in the portion that becomes the needle-like body due to the selective heating, rearrangement of the atoms constituting the Si-based thin film occurs. For this reason, larger crystal grains are formed in this portion, and the crystallinity of this portion is increased.

Therefore, according to the manufacturing method of the present invention, as described in claim 1 above, the needle-like body is made smaller than the polycrystalline Si-based thin film or the amorphous Si-based thin film constituting the movable part. Thus, a semiconductor micromachine made of a Si-based thin film having a crystal structure closer to a single-crystal Si-based thin film can be manufactured. Therefore, it is possible to obtain a semiconductor micromachine having almost no variation in mechanical characteristics of the needle-shaped body.

Next, according to the invention of claim 6, the above Si
The protective thin film is provided with a protective film for preventing breakage due to thermal expansion during the selective heating. After the protective film is formed, the portion of the Si-based thin film to be the needle-like body is selectively heated. Is preferred. This makes it possible to suppress the damage of the Si-based thin film due to thermal expansion and grow the crystal grains of the Si-based thin film serving as needles. As the protective film, for example, SiN, SiON, SiO ₂ , PSG, arsenic glass, or the like can be used.

Next, as in the seventh aspect of the present invention, it is preferable that the heating means in the heating be selected from any one of laser light, lamp light and current. This makes it possible to supply heat energy only to a necessary part, and to enhance heating selectivity.

Next, as in the eighth aspect of the present invention, the heating means in the heating is a laser beam or a lamp beam, and it is preferable that these beams are narrowed down to a thickness of a needle-like body. . Thus, the Si-based thin film in the portion that becomes the needle-like body can be selectively and efficiently heated. In addition,
When the substrate is composed of a single-crystal Si substrate, the laser beam is directed to a portion where the Si-based thin film and the substrate are joined, starting from the portion where the Si-based thin film is joined to the substrate, and moving toward the movable portion. Alternatively, irradiation with lamp light is preferred. As a result, it is possible to obtain a Si-based thin film that becomes a needle-like body from the crystal information on the substrate, and to form a needle-like body made of a single-crystal Si-based thin film.

Next, as in the ninth aspect of the present invention, the light absorption of the Si-based thin film in the portion serving as the needle-like body is made higher than the light absorption of the Si-based thin film in the portion serving as the movable portion. Is preferred. Thereby, when heating by laser light or lamp light, the Si-based thin film in the portion that becomes the needle-like body can be selectively and efficiently heated.

As a method of controlling the light absorption rate,
There is a method of providing a single-layer or multi-layer film as described in claim 10 below. Alternatively, it is preferable to control the film thickness of the underlying layer below the Si-based thin film, and to form a single layer or a multilayer. This makes it possible to change the light reflectance of the underlayer, and thus the light absorptance of the Si-based thin film.

Preferably, a semiconductor layer having a narrower band gap than that of the Si-based thin film is provided on a surface or a lower portion of a portion of the Si-based thin film which will be a needle-like body. Thus, by selecting and irradiating a wavelength which is not absorbed by the Si-based thin film but can be absorbed only by the semiconductor layer, the Si-based thin film in a portion to be a needle is easily and efficiently heated. be able to.

Next, as in the tenth aspect of the present invention, the S
It is preferable that a SiN film, a SiON film, and a SiO ₂ film are provided in the i-type thin film in a single layer or a multilayer. Thus, the Si-based thin film in the portion that becomes the needle-like body can be selectively and efficiently heated. In addition, it is preferable to provide the above-mentioned film so that the light absorption of the Si-based thin film in the portion that becomes the needle-shaped body becomes high and the light absorption of the Si-based thin film in the portion that becomes the movable portion becomes low.

Next, as in the eleventh aspect of the present invention, the S
It is preferable that the i-type thin film is provided with a carbon thin film. The portion provided with the carbon thin film has a high heat absorption rate. Therefore, efficient heating can be performed. It is preferable that the carbon thin film is provided on the Si-based thin film in a portion to be the needle-like body.

[0054]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment A semiconductor micromachine and a method of manufacturing the same according to an embodiment of the present invention will be described with reference to FIGS. Note that the semiconductor micromachine of this example is an angular velocity sensor created by micromachining technology. As shown in FIG. 1, the semiconductor micromachine 1 of the present embodiment has a substrate 12 and a movable portion 13 which is opposed to the substrate 12 with a gap 11 provided therebetween and supported by a needle 15.

The movable portion 13 is made of a polycrystalline Si-based thin film, and the needle-like body 15 is made of a polycrystalline material composed of crystal grains having a larger particle diameter than the polycrystalline Si-based thin film constituting the movable portion 13. It is made of a Si-based thin film.

When the movable part 13 and the needle-like body 15 in the semiconductor micromachine 1 are formed, first, the movable part 13 is attached to the surface of the substrate 12.
And a movable-part-side base material for forming a Si-based thin film,
An acicular body-side base material on which a Si-based thin film to be the acicular body 15 is formed is prepared.

Next, an Si-based thin film is formed on the movable portion-side base material and the needle-shaped body-side base material by using a CVD method (chemical vapor deposition method), and the formation of the Si-based thin film is performed. In the initial stage, the core density of the movable part-side base material is maintained higher than the core density of the needle-shaped body-side base material. Then, doping of the Si-based thin film, heat treatment for activating the dopant and relaxing strain of the Si-based thin film are performed, and the Si-based thin film is processed into the shape of the movable portion 13 and the needle-like body 15. . After that, the base material is removed, and the gap 11 is formed.

Next, a detailed structure of the semiconductor micromachine 1 will be described. As shown in FIG. 1, the semiconductor micromachine 1 of the present embodiment includes a substrate 12 and a movable portion 13 which is disposed to face the substrate 12 with a gap provided therebetween and supported by a needle 15. The movable electrode 13 is provided with a drive electrode 161 and a detection electrode 162. Further, a pair of fixed portions 17 fixed to the substrate 12 are provided on both sides of the movable portion 13. Note that at least one of the driving electrode portions 161 is connected to the substrate 1 of the movable portion 13.
It can also be used as an electrode for detecting vibration in the direction parallel to 2.

On both sides of the movable section 13, a comb-shaped drive electrode section 161 is provided. In addition, the fixing portion 17 includes:
A comb-shaped fixed-part-side driving electrode 171 is provided so as to mesh with the driving electrode 161.
A fine gap 178 is provided between the driving electrode portion 161 and the fixed portion-side driving electrode portion 171. The needle-like body 15 is supported and fixed to the substrate 12 by leg portions 559 as shown in FIG.

As shown in FIGS. 2 (b) and 4 (b), the position of the movable part 13 between the substrate 12 and the movable part 13 is opposite to the position of the movable part 13 facing the detection electrode 162. The distance detecting electrode 18 for detecting the distance of the gap portion 11 is provided. The needle 15 is connected to an electrode pad 158, and the electrode pad 158 is connected to a drive circuit or a detection circuit.

Next, a detailed manufacturing method of the semiconductor micromachine 1 will be described. In addition, FIG.
3 (c) and FIGS. 3 (a) and 3 (b) show the semiconductor micromachine 1 in the horizontal direction in FIG.
2 is a drawing showing a cross section cut along line A and explaining the manufacturing process. 4 (a) to 4 (c) and FIG.
(A) and (b) correspond to FIGS. 2 (a) to (c) and FIG.
FIG. 2 is a diagram illustrating a manufacturing process corresponding to (a) and (b), but is a diagram illustrating a cross section of the semiconductor micromachine 1 cut in a vertical direction in FIG. 1, that is, along a line BB.

FIGS. 6 (a-1) to 6 (c) and FIG.
FIGS. 2 (a) to 2 (c) and FIG.
FIG. 2 is a diagram illustrating a manufacturing process corresponding to (a) and (b), but is a diagram illustrating a cross section of the semiconductor micromachine 1 cut in a vertical direction in FIG. 1, that is, along a line CC. That is, FIGS. 6A-1 and 6A-2 correspond to FIG.
FIG. 5A is an explanatory view of a step corresponding to FIG. 4A, and the same applies to other drawings hereinafter.

First, phosphorus is applied to a substrate 12 made of a p-type Si single crystal by using a resist pattern formed by a photolithography process as a mask, at an acceleration voltage of 20 keV and 5E16.
Ion implantation was performed under the condition of cm ⁻² . Thereafter, annealing was performed on the substrate 12 under the conditions of an N ₂ atmosphere, 1000 ° C., and 30 minutes. Thus, the substrate 12, the distance detecting electrode 18 provided on the surface of the substrate 12, and the wiring in the semiconductor micromachine 1 were obtained.

Next, an etching stopper layer 54 is provided on the substrate 12 in order to prevent erosion of the substrate 12 by an etching solution described later and diffusion of impurities from the etching layer 54. That is, the surface of the substrate 12
Using H ₄ and NH ₃ as source gases and H ₂ as carrier gas
At a temperature of 800 ° C., a 100 nm thick S
Form i ₃ N ₄ . This becomes the etching stopper layer 54. Further, an SiO ₂ layer may be formed between the etching stopper layer 54 and the substrate 12.

Next, on the surface of the etching stopper layer 54, by using SiH ₄ , PH ₃ , O ₂ as a source gas and N ₂ as a carrier gas, the temperature of the substrate 12 is maintained at 400 ° C., and normal pressure CVD is performed. And an etching layer 55 made of PSG (phosphorus glass) having a thickness of 1.5 μm.

Next, FIGS. 2 (a), 4 (a), and 6 (a)
As shown in -1), on the surface of the etching layer 55,
Using SiH ₄ , NH ₄ as a source gas and H ₂ as a carrier gas, a temperature of 800 ° C. and a thickness of 100 nm by reduced pressure CVD.
A base film 50 made of Si ₃ N ₄ is formed.

Then, as shown in FIG. 6A-2, the base film 50 is etched by RIE using the resist pattern formed by the photolithography process as a mask. As a result of this etching, the polycrystalline S
The base film 50 is peeled off from the portion where the i-type thin film 57 is formed, leaving the etching layer 55 exposed. On the other hand, the portion where the polycrystalline Si-based thin film 57 to be the movable portion 13 is formed. , The base film 50 remains as it is. As a result, the movable portion-side base material 531, which is composed of the etching layer 55 and the base film 50 provided on the surface thereof,
And the needle-shaped body-side base material 5 composed of only the etching layer 55
32.

Next, FIG. 2B, FIG. 4B, FIG.
As shown in (b), the etching stopper layer 54, the etching layer 55, and the base film 5 are formed by RIE using the resist pattern formed by the photolithography process as a mask.
0 is etched to form a contact hole 500 that exposes the substrate 12 and penetrates them.

Next, FIG. 2C, FIG. 4C, FIG.
As shown in (c), a polycrystalline Si-based thin film 57 having a thickness of 2 μm is formed by low pressure CVD at 750 ° C. using SiH ₄ as a source gas and H ₂ as a carrier gas. This time,
A leg 559 integrated with the polycrystalline Si-based thin film 57 is also formed in the contact hole 500 at the same time. This portion serves as a support for supporting the needle-like body 15 in the semiconductor micromachine 1. Further, when forming the Si-based thin film, the growth conditions of the Si-based thin film may be changed after the Si-based thin film is formed on the entire surface.

Next, FIG. 3A, FIG. 5A and FIG.
As shown in FIG. 2A, phosphorus as a dopant is doped using ion implantation. By this doping, in the semiconductor micromachine 1, the detection electrode 1
62, the driving electrode portion 161, the fixed portion 17, and the region acting as the fixed portion-side driving electrode portion 171 can be provided with conductivity.

Next, these substrates 12 are subjected to a heat treatment at 1000 ° C. for 30 minutes in a nitrogen atmosphere using an annealing furnace. This alleviates the internal stress of the polycrystalline Si-based thin film 57 and activates the dopant contained therein. Instead of the ion implantation and the heat treatment, gas phase diffusion or doping by solid phase diffusion may be used.

Next, FIG. 3A, FIG. 5A and FIG.
As shown in (a), a resist pattern is formed by a photolithography process, and the resist pattern is used as a mask to form a resist pattern.
The polycrystalline Si-based thin film 57 is etched by IE. At this time, the base film 50 may be etched using the same pattern as a mask. Thereby, the movable part 1
3, a driving electrode portion 16 provided on a side surface of the movable portion 13
1, needle-like body 15, fixed part 17, fixed part side driving electrode part 1
The part to be 71 is formed. Note that the polycrystalline Si-based thin film 57 is provided with a large number of introduction holes 579 of about 4 μm square as holes for introducing an etching solution described later.

Next, an etching process is performed on the etching layer 55. In the etching process, buffered hydrofluoric acid (BFH) was used as an etching solution. By the above-mentioned etching treatment, the above-mentioned etching solution penetrates into the etching layer 55 below the polycrystalline Si-based thin film 57 from the etching region of the polycrystalline Si-based thin film 57, and erodes the etching layer 55.

As a result, as shown in FIGS. 3B, 5B, and 7B, a gap 11 is formed between the polycrystalline Si-based thin film 57 and the substrate 12. Thereafter, the resultant is washed with pure water, replaced with alcohol (IPA), and then dried. Thus, the semiconductor micromachine 1 according to the present example was obtained.

Next, the operation and effect according to this embodiment will be described. In the above manufacturing method, the substrate 12 has a movable portion-side base material 531 for forming the polycrystalline Si-based thin film 57 serving as the movable portion 13 and the polycrystalline Si-based thin film 57 serving as the needle-like body 15.
Is formed, and a polycrystalline Si-based thin film 57 is formed under the following conditions. Here, the condition means that the polycrystalline S
In the initial stage of the formation of the i-based thin film 57, the core density of the movable part-side base material 531 is maintained higher than the core density of the needle-shaped body-side base material 532.

In the present embodiment, the movable part-side base material 531 is composed of an etching layer 55 on which a base film 50 made of Si ₃ N ₄ is formed.
Consists of an etching layer 55. That is, the surface of the movable portion-side base material 531 is formed of Si ₃ N _4, and the needle-shaped body-side base material 532 is formed of PSG.

By the way, in the above-mentioned CVD method, FIG.
(A) and (b), as shown in FIG.
A crystal nucleus 535 is formed on the base material 1 and the needle-shaped body base material 532, and the source gas reacts on the surface of the crystal nucleus 535, and the reacted source gas diffuses on the surface of each base material 531 and 532, and The crystal grains 536 of the polycrystalline Si-based thin film 57 are absorbed by the crystal nuclei 535. The core density of the surface of the movable part-side base material 531 is high as shown in FIG. 8B, and the core density of the surface of the needle-shaped body base material 532 is
As shown in FIG.

For this reason, as shown in FIG. 8B, small crystal grains 53 are formed on the surface of the movable portion base material 531.
6 grows, and large crystal grains 536 grow on the surface of the needle-shaped base material 532 as shown in FIG. For these reasons, according to the present invention, the crystal grains 536 of the needle-like body 15 can be made larger than the crystal grains 536 of the movable portion 13. Therefore, the needle-like body 15 is in a state closer to a single crystal.

The needle 15 is an important part that supports the movable part 13 and determines the state of vibration of the movable part 13. Since this needle-like body 15 is in a state close to a single crystal, there is almost no variation in mechanical characteristics. Therefore, since there is almost no variation in the spring constant and the like of the needle-like body 15, there is almost no variation in the horizontal vibration of the movable portion 13.

As shown in the prior art, the angular velocity in the semiconductor micromachine 1 of this embodiment is
It is detected based on vertical vibration generated by horizontal vibration and Coriolis force in the movable section 13. As described above, the semiconductor micromachine 1 according to the present example functions as an angular velocity sensor capable of accurately detecting an angular velocity with little variation in characteristics.

Embodiment 2 In this embodiment, as shown in FIG. 9, a method of manufacturing a semiconductor micromachine in which crystal grains in the needle-like body are enlarged by using laser light will be described. The semiconductor micromachine 1 according to the present embodiment is the same as that of the first embodiment and that shown in FIG.

Hereinafter, a method for manufacturing the semiconductor micromachine 1 according to this embodiment will be described. As shown in FIG. 2A and the like, a substrate 12 in the semiconductor micromachine 1, a distance detection electrode 18 provided on the surface of the substrate 12, and wiring were obtained in the same manner as in the first embodiment. Then, an etching stopper layer 54 is provided on the substrate 12. At this time, an SiO ₂ layer may be formed between the substrate 12 and the etching stopper layer 54. Next, an etching layer 55 made of PSG is formed on the surface of the etching stopper layer.
Is provided.

Next, as shown in FIG. 2B and the like, the etching stopper layer 54 and the etching layer 55 are etched to form a contact hole 500 that penetrates them and exposes the substrate 12. Next, as shown in FIG. 2 (c) and the like, using SiH ₄ as a source gas and H ₂ as a carrier gas, a thickness of 2μ
Then, a polycrystalline Si-based thin film 57 of m is formed. At this time, a leg 559 integrated with the polycrystalline Si-based thin film 57 is also formed in the contact hole 500 at the same time. The Si-based thin film may be amorphous, and may be formed by vapor deposition sputtering, plasma CVD, ECR, or plasma CVD.

Next, the above polycrystalline Si-based thin film 57 is doped with phosphorus, and then these substrates 12 are subjected to a heat treatment using an annealing furnace in a nitrogen atmosphere at a temperature of 1000 ° C. for 30 minutes. Do. Instead of the above doping, phosphorus doping may be performed when the Si-based thin film 57 is formed. Further, the dopant may be As or Sb.

Next, as shown in FIG. 9, the He—Ne laser beam is applied to the polycrystalline Si-based thin film
Irradiate 32. At the time of this irradiation, the laser light is prevented from irradiating the polycrystalline Si-based thin film 631 in the portion to be the movable portion 13. This step may be performed in a high-temperature atmosphere (about 900 ° C.). In addition, the irradiation intensity of the laser light is adjusted so that the surface temperature of the region irradiated with the laser light becomes 1000 to 1050 ° C. In addition,
The light used for the irradiation may be light emitted from any light source as long as the photon energy is larger than the band gap of Si. For example, lamp light can be used.

Next, in the same manner as in the first embodiment, a resist pattern is formed by a photolithography process, and the polycrystalline Si is formed by RIE using the resist pattern as a mask.
The system thin film 57 is etched. Thereby, the movable part 1
3, a driving electrode portion 16 provided on a side surface of the movable portion 13
1, needle-like body 15, fixed part 17, fixed part side driving electrode part 1
The part to be 71 is formed. The heating by the laser beam is carried out by the polycrystalline Si-based thin film 57 by the photolithography process.
After patterning.

Thereafter, similarly to the first embodiment, the etching layer 55 is removed by etching to form a gap. Thus, a semiconductor micromachine is obtained.

In the manufacturing method of the present embodiment, a portion of the polycrystalline Si
The system thin film 631 is heated. Thereby, the crystal grains of the polycrystalline Si-based thin film 632 in the portion that becomes the needle-like body 15 can be increased. Therefore, the needle-like body 15 in a state closer to a single crystal can be obtained. Others have the same operation and effects as the first embodiment.

Third Embodiment As shown in FIG. 10, this embodiment is a method for manufacturing a semiconductor micromachine in which the crystal grains in the needle-like body are enlarged using laser light, as in the second embodiment. However, in the manufacturing method of this example, the polycrystalline S
The following dielectric film is provided in advance for the i-type thin film. It should be noted that the manufacturing method of the present embodiment is different from the first embodiment in FIG.
1 can be manufactured.

In the manufacturing method according to the present embodiment, a polycrystalline Si-based thin film 57 is provided on the surface of the etching layer 55, and is doped with phosphorus.
The steps up to the heat treatment of the substrate 12 provided with the polycrystalline Si-based thin film 57 and the like are the same as in the second embodiment.

After the heat treatment, the polycrystalline Si-based thin film 57
Using SiH ₄ and NH ₃ as source gases and H ₂ as carrier gas at a temperature of 800 ° C. and low pressure CVD to form Si ₃ N
_A first dielectric film 641 of 4 is formed. Thereafter, as shown in FIG. 10, the portion of the first dielectric film 641 provided on the polycrystalline Si-based thin film 632, which is to be the needle-like body 15, is removed by etching.

Then, the same polycrystalline Si-based thin film 632 as the needle-like body 15 and the polycrystalline Si-based thin film 631 as the movable part 13 are formed in the same manner as the first dielectric film 631. A second dielectric film 642 of the same component is provided by the method. At this time, the film thickness is controlled so that the reflectance on the polycrystalline Si-based thin film 631 is high and the reflectance on the polycrystalline Si-based thin film 632 is low with respect to the wavelength of the heating light.
As a result, a two-layer dielectric film is formed on the polycrystalline Si-based thin film 631, and a single dielectric film is formed on the polycrystalline Si-based thin film 632. The first and second dielectric films 641 and 642 may be formed by plasma CVD or sputtering.

Next, in the same manner as in the second embodiment, a laser beam is applied to the portion of the polycrystalline Si-based thin film which will become the needle-like body 15. Further, the entire surface may be irradiated with laser light. In addition, the surface temperature of the polycrystalline Si-based thin film that becomes the needle-like body 15 during irradiation is preferably 1000 ° C. to 1050 ° C., and is preferably maintained at this temperature for 30 minutes or more. After the laser beam irradiation, the first and second dielectric films 641 and 642 are preferably removed. Next, in the same manner as in Embodiment 2, the polycrystalline Si-based thin film is etched and the movable portion 13, the driving electrode portion 161 provided on the side surface of the movable portion 13, the needle-like body 15, and the fixed portion 1 are formed.
7. A part to be the fixed part side drive electrode part 171 is formed. Thereafter, in the same manner as in the first embodiment, the etching layer is removed by etching to form a gap. Thus, a semiconductor micromachine is obtained.

In the manufacturing method of this embodiment, the polycrystalline Si-based thin film 631 serving as the movable portion 13 has a high reflectivity of laser light, and the polycrystalline Si-based thin film 6 serving as the acicular body 15 is maintained.
The reflectance of the laser light at 32 is kept low. Therefore, the polycrystalline Si-based thin film 63 serving as the needle-like body 15 is formed.
2 can be heat-treated at a higher temperature than the polycrystalline Si-based thin film 631 serving as the movable portion 13. Others have the same operation and effects as the first embodiment.

Note that the first and second dielectric films 63 of this example are
1,632 is made of Si ₃ N ₄ , which is referred to as SiO ₂ ,
It can also be composed of a film of SiON or Al ₂ O ₃ .

Embodiment 4 This embodiment is a method of manufacturing a semiconductor micromachine in which the crystal grains in the needle-like body are enlarged using laser light, as in Embodiment 2. By the manufacturing method of this example,
The semiconductor micromachine 1 according to the first embodiment and FIG. 1 can be manufactured.

In the manufacturing method according to this embodiment, a polycrystalline Si-based thin film 57 is provided on the surface of the etching layer, and phosphorus is doped into the polycrystalline Si-based thin film 57. Thereafter, the etching layer and the polycrystalline S
The process up to the heat treatment of the substrate 12 provided with the i-type thin film and the like is the same as that of the second embodiment.

Next, in the same manner as in the first embodiment, a resist pattern is formed by a photolithography process, and the polycrystalline Si is formed by RIE using the resist pattern as a mask.
Etch the system thin film. Thereby, the movable part 13, the drive electrode part 161 provided on the side surface of the movable part 13, the needle-like body 15, the fixed part 17, and the part to be the fixed part side drive electrode part 171 are formed.

Next, the polycrystalline Si-based thin film was treated with S
Using iH ₄ and O ₂ as source gases and N ₂ as carrier gas,
The temperature of the substrate 12 is maintained at 400 ° C., and a 0.5 μm thick protective film made of SiO ₂ is formed by normal pressure CVD.

Next, He-Ne laser light condensed using a lens or a concave mirror to about the thickness of the needle-like body 15 is irradiated and scanned in the longitudinal direction of the needle-like body 15. In this irradiation / scanning, it is preferable to select the scanning direction of the laser beam from the contact portion between the needle-like body 15 and the substrate 12 as the starting point and toward the movable portion 13 from here. Further, by the irradiation of the laser beam, Si
It is preferable to melt-recrystallize the system thin film 57, whereby the needle-like body 15 having high quality crystallinity can be obtained. Thereafter, in the same manner as in the first embodiment, the etching layer 55 and the protective film made of SiO ₂ are removed by etching to form a gap. Thus, a semiconductor micromachine is obtained.

According to the manufacturing method of the present example, the polycrystalline Si-based thin film serving as a needle is melted and recrystallized. For this reason, the needle-shaped body can have high crystallinity. In addition, it becomes possible to single-crystallize the needle-like body during the recrystallization. Therefore, an excellent semiconductor micromachine can be obtained. Others have the same operation and effects as the first embodiment.

[0102] Incidentally, the protective film, Si ₃ N ₄ was used in Embodiment Example 3 in place of SiO _2, SiO _2, SiO
A dielectric film having a low reflectance of He—Ne laser light (reflectance of 0.2 or less) of a single layer or a multilayer of N and Al ₂ O ₃ films may be used.

Fifth Embodiment As shown in FIG. 11, this embodiment is a method of manufacturing a semiconductor micromachine in which a current is applied to heat a polycrystalline Si-based thin film in a portion that becomes a needle-like body. The semiconductor micromachine 1 according to the first embodiment and FIG. 1 can be manufactured by the manufacturing method of the present embodiment.

In the manufacturing method according to the present example, a polycrystalline Si-based thin film 57 is provided on the surface of the etching layer 55, and phosphorus is doped into the thin film.
The steps up to the heat treatment of the substrate 12 provided with the polycrystalline Si-based thin film 57 and the like are the same as in the second embodiment.

After the completion of the heat treatment, the polycrystalline Si-based thin film 57 is etched in the same manner as in the second embodiment, and the movable portion, the driving electrode portion provided on the side surface of the movable portion, the needle-like body, and the fixed member are fixed. Then, a part to be the driving electrode part on the side of the fixed part is formed.

After the patterning of the Si-based thin film, a current is applied to the polycrystalline Si-based thin film 632 in a portion to be a needle. As shown in FIG. 11, the current is supplied by using a current source 65 and the temperature of the polycrystalline Si-based thin film 632 is set to 1000 to 1050.
Adjust the current so that the temperature becomes ° C. In addition, as a current supply path of the current, a current supply path such as a dotted line shown in FIG. 11 using the leg 559 and the conductive portion 189 provided below the leg 559 can be exemplified.

In addition to the above, a portion where another needle-like body and the substrate are joined via the needle-like body-movable part-needle-like body can be used as a current supply path. Thereafter, in the same manner as in the first embodiment, the etching layer 55 is removed by etching to form a gap. Thus, a semiconductor micromachine is obtained. Others are the same as the first embodiment. Further, the manufacturing method of this example also has the same operation and effect as the first embodiment.

[0108]

As described above, according to the present invention, it is possible to provide a semiconductor micromachine having a small variation in characteristics and a method of manufacturing the same.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view of a semiconductor micromachine according to a first embodiment;

FIG. 2 is an explanatory view illustrating a manufacturing process of the semiconductor micromachine according to the first embodiment.

FIG. 3 is an explanatory view showing a manufacturing step of the semiconductor micromachine, following FIG. 2;

FIG. 4 is an explanatory view showing a manufacturing process of the semiconductor micromachine according to the first embodiment.

FIG. 5 is an explanatory view showing a manufacturing step of the semiconductor micromachine, following FIG. 4;

FIG. 6 is an explanatory diagram illustrating a manufacturing process of the semiconductor micromachine according to the first embodiment.

FIG. 7 is an explanatory view showing the manufacturing process of the semiconductor micromachine, following FIG. 6;

8A and 8B are explanatory diagrams of crystal grains in a needle-like body and FIG. 8B are explanatory diagrams of crystal grains in a movable portion according to the first embodiment.

FIG. 9 is an explanatory diagram of heating of a polycrystalline Si-based thin film at a portion to be a needle-like body using laser light according to the second embodiment.

FIG. 10 is an explanatory diagram showing a state in which a dielectric film is provided on the surface of a polycrystalline Si-based thin film according to the third embodiment.

FIG. 11 is an explanatory diagram of heating using a current to a polycrystalline Si-based thin film in a portion to be a needle-like body according to the fifth embodiment.

[Explanation of symbols]

 1. . . Semiconductor micromachine, 11. . . 11. a gap; . . Substrate, 13. . . Movable part, 15. . . Needles, 531. . . Moving part side base material, 532. . . Needle-like base material, 55. . . Etching layer, 57, 631, 632. . . Polycrystalline Si thin film,

Claims (11)

[Claims] 1. A semiconductor micromachine having a substrate and a movable portion which is opposed to the substrate with a gap provided therebetween and supported by a needle-like body, wherein the movable portion is a polycrystalline Si-based thin film or an amorphous material. The needle-shaped body is made of a single-crystal Si-based thin film, or the movable part is made of an amorphous Si-based thin film, and the needle-shaped body is made of polycrystalline Si.
The movable part and the needle-shaped body are both made of a polycrystalline Si-based thin film, and the needle-shaped body has a larger particle size than the polycrystalline Si-based thin film constituting the movable part. A semiconductor micromachine comprising a polycrystalline Si-based thin film composed of crystal grains. 2. A semiconductor micromachine comprising: a substrate; and a movable portion which is opposed to the substrate with a gap provided therebetween and is supported by a needle-like body, wherein the movable portion is a polycrystalline Si-based thin film or a non-conductive thin film. The needle-shaped body is made of a single-crystal Si-based thin film, or the movable part is made of an amorphous Si-based thin film, and the needle-shaped body is made of polycrystalline Si.
The movable part and the needle-shaped body are both made of a polycrystalline Si-based thin film, and the needle-shaped body has a larger particle size than the polycrystalline Si-based thin film constituting the movable part. In manufacturing a semiconductor micromachine characterized by being made of a polycrystalline Si-based thin film composed of crystal grains, in producing the movable portion and the needle-like body, first, an Si serving as a movable portion is placed on the substrate with respect to the substrate. Forming a base material for the movable part for forming a base thin film and a base material for the needle-shaped body for forming a Si-based thin film to be a needle-like body, and then forming the base material for the movable part and the base material for the needle-shaped body A Si-based thin film is formed on the surface of the base material, and in the initial stage of the formation of the Si-based thin film, the nucleus density of the movable part-side base material is maintained higher than that of the needle-shaped body-side base material. And then The semiconductor according to claim 1, wherein the Si-based thin film is processed into the shape of the movable portion and the needle-like body, and then the movable portion-side base material and the needle-like body base material are removed to form the gap. Micromachine manufacturing method. 3. The method according to claim 1, wherein in forming the Si-based thin film, SiH ₄ ,
A method for manufacturing a semiconductor micromachine, comprising using at least one selected from GeH ₄ and CH ₄ . 4. The needle-shaped base material according to claim 2, wherein the needle-shaped base material is more Si ₃ N ₄ >SiN>SiON> SiO ₂ than the material selected as the movable part base material.
> BSG (boron glass)> PSG (phosphorus glass)> B
A method of manufacturing a semiconductor micromachine, comprising selecting a lower material in the order of PSG (borophosphosilicate glass). 5. A semiconductor micromachine comprising: a substrate; and a movable portion which is opposed to the substrate with a gap provided therebetween and supported by a needle-like body, wherein the movable portion is a polycrystalline Si-based thin film or The needle-shaped body is made of a single-crystal Si-based thin film, or the movable part is made of an amorphous Si-based thin film, and the needle-shaped body is made of polycrystalline Si.
The movable part and the needle-shaped body are both made of a polycrystalline Si-based thin film, and the needle-shaped body has a larger particle size than the polycrystalline Si-based thin film constituting the movable part. In manufacturing a semiconductor micromachine characterized by comprising a polycrystalline Si-based thin film composed of crystal grains, in preparing the movable portion and the needle-like body, first, a base material is formed on the substrate, Next, a Si-based thin film is formed on the base material,
Processing the thin film based on the shape of the movable portion and the needle-like body, selectively heating the Si-based thin film in the portion to be the needle-like body, and then removing the base material to form the gap. A method of manufacturing a semiconductor micromachine. 6. The needle-like body according to claim 5, wherein the Si-based thin film is provided with a protective film for preventing damage due to thermal expansion during the selective heating, and after forming the protective film. A method for manufacturing a semiconductor micromachine, comprising selectively heating a Si-based thin film in a portion to be formed. 7. The method for manufacturing a semiconductor micromachine according to claim 5, wherein the heating means in the heating is selected from one of laser light, lamp light, and current. 8. The semiconductor according to claim 5, wherein the heating means in the heating is a laser beam or a lamp beam, and these beams are reduced to a thickness of a needle-like body. Micromachine manufacturing method. 9. The method according to claim 5, wherein
A method for manufacturing a semiconductor micromachine, characterized in that the light absorption of the Si-based thin film in the portion serving as the needle-like body is higher than the light absorption of the Si-based thin film in the portion serving as the movable portion. 10. The method of manufacturing a semiconductor micromachine according to claim 9, wherein the Si-based thin film is provided with a single-layer or multi-layer SiN film, a SiON film, and a SiO ₂ film. 11. The method according to claim 9, wherein a carbon thin film is provided on the Si-based thin film.