JP2000309000A - Semiconductor device, and semiconductor micro-actuator, semiconductor micro-valve and semiconductor micro- relay which all use same device, and manufacture of semiconductor device and manufacture of semiconductor micro-actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device that is low in electric power consumption and simple in manufacture, a semiconductor micro-actuator, semiconductor micro-valve and semiconductor micro-relay that use the above device, and a manufacturing method of semiconductor devices and a manufacturing method of semiconductor micro- actuators. SOLUTION: Flexible regions 2 are each connected at one end to a semiconductor board 3 as a frame via a heat insulating region 7, and at the other to a movable element 5. Each heat insulating region 7 consists of a heat insulating material of such a resin as a polyimide and a fluorine-contained resin. Each flexible region 2 is constituted of a thin portion 2S and a thin film 2M differing in the coefficient of thermal expansion. When a diffused resistor 6 formed on the obverse side of each thin portion 2S is heated up, the differential thermal expansion between the thin portion 2S and the thin film 2M displaces the flexible region 2 with the result that the movable element 5 is displaced relative to the semiconductor board 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device comprising a semiconductor substrate, a flexible region separated from the semiconductor substrate and displaced by a change in temperature, and a heat insulating region provided between the semiconductor device and the semiconductor device. The present invention relates to a semiconductor microactuator, a semiconductor microvalve, a semiconductor microrelay, and a method for manufacturing a semiconductor microactuator.

[0002]

2. Description of the Related Art A semiconductor device comprising a semiconductor substrate, a flexible region which is separated from the semiconductor substrate and is displaced by a change in temperature, and a semiconductor device comprising a heat insulating region provided between the semiconductor substrate and the semiconductor substrate has different thermal expansions. There is a semiconductor microactuator that combines at least two materials having a coefficient (bimetal structure), heats that portion, and obtains displacement using a difference in thermal expansion coefficient. This semiconductor microactuator is disclosed in Japanese Patent Publication No. 4-506392, "Semiconductor Microactuator".

A semiconductor microactuator described in Japanese Patent Application Laid-Open No. 4-506392 is a top view of FIG.
As shown in the cross-sectional view of FIG. 54, a flexible region having a bimetal structure in which an aluminum thin film 304 is formed on a part of a silicon diaphragm 300 is provided. When an electric current is applied to the heater 301 formed in the diaphragm 300 made of silicon, heat is generated, and the diaphragm 3 is heated.
00 temperature rises. Here, since silicon and aluminum have significantly different coefficients of thermal expansion, a thermal stress is generated to deflect the diaphragm 300, thereby displacing the movable portion 305 connected to the diaphragm 300.
In order to obtain an efficient displacement, the diaphragm 300
A hinge 303 of a silicon dioxide thin film is provided between the periphery of the
This structure prevents the heat generated at 0 to escape to the silicon frame 302.

[0004] However, the semiconductor microactuator having such a structure has the following problems. First, the thermal insulation effect of the hinge structure of the silicon dioxide thin film will be considered. Generally, the amount of heat Q escaping from the high-temperature portion to the low-temperature portion is as follows: Q (W) = − λ ((t ₂ −t ₁ ) / δ) A (Formula X)

Here, Q; heat quantity (speed of heat transfer) t ₂ −t ₁ ; temperature difference (° C.) δ; distance from heat source (cm) A: cross section perpendicular to the direction of heat flow (cm ² ) λ Thermal conductivity (J / cm · s · ° C.).

Therefore, the amount of heat escaping from the diaphragm 300 to the silicon frame 302 is calculated using this relational expression.
The temperature difference between the diaphragm 300 and the silicon frame 302 is reduced by 15
0 ° C., width of hinge 303 is 30 μm, diaphragm 3
00 has a diameter of 2.5 mm, and the thickness of the hinge 303 is 2 μm.
("Electrically-Activated, Micromachined Diaphr
am Valves '' Technical Digest IEEE Solid-Stat
e Sensor and Actuator Workshop, pp65-69, June
Estimated from 1990), the section A1 perpendicular to the direction of heat flow
A1 = 2.5 mm × π × 2 μm = 0.25 cm × π × 2
× 10 ⁻⁴ cm = 1.57 × 10 ⁻⁴ cm ² , and the thermal conductivity of silicon dioxide λ = 0.084 (W /
cm · ° C.), the amount of heat Q1 that escapes is: Q1 = 0.084 (W / cm · ° C.) × 150 ° C./(30
× 10 ⁻⁴ cm) × 1.57 × 10 ⁻⁴ cm ² = 0.66 W
= 660 mW. Next, the case where the hinge structure of silicon dioxide is not provided is calculated. When the thickness of the silicon diaphragm 300 is 10 μm and the cross section A2 perpendicular to the direction of the heat flow is calculated, A2 = 2.5 mm × π × 10 μm = 0.25 cm × π ×
10 × 10 ⁻⁴ cm = 7.85 × 10 ⁻⁴ cm ² , and the thermal conductivity of silicon λ = 1.48 (W / cm ·
° C), the amount of heat Q2 that escapes is: Q2 = 1.48 (W / cm · ° C) x 150 ° C / (30 x
10 ⁻⁴ cm) × 7.85 × 10 ⁻⁴ cm ² = 58 W Thus, by providing the silicon dioxide thin film hinge 303, a thermal insulation effect of about 90 times was obtained. As described above, the semiconductor microactuator described in Japanese Patent Application Laid-Open No. 4-506392 has a structure with higher thermal efficiency than that of the conventional structure. However, in consideration of the current use, further reduction of heat loss is desired. Specifically, this heat release (heat loss) is considered to be power (power consumption) constantly supplied to maintain the diaphragm 300 at a predetermined temperature (for example, 150 ° C.).

The power consumption of the semiconductor microactuator described in Japanese Patent Application Laid-Open No. 4-506392 can be estimated to be several hundred mW (660 mW in calculation). In consideration of this, it is desirable that the power is not more than 100 mW.

Further, in the semiconductor microactuator described in Japanese Patent Publication No. 4-506392, the portion of the silicon dioxide thin film at the hinge 303 is as thick as 2 μm. The factor that determines the thickness of the silicon dioxide thin film of the hinge 303 is not clearly described in the specification. However, when the semiconductor microactuator described in Japanese Patent Application Laid-Open No. 4-506392 is used for a microvalve or the like, the pressure applied to the movable element causes the hinge 30 to move.
It is expected that the film thickness will be concentrated to 3, and a film thickness that does not break down under this pressure is required. However, when the thickness of the hinge 303 is increased, the thermal insulation effect is reduced as indicated by the above-mentioned heat release calculation formula (formula X). Therefore, it can be estimated that 2 μm is determined as the thickness of the silicon dioxide thin film having a certain strength and a thermal insulation effect.

As described in the specification, the semiconductor microactuator described in Japanese Patent Application Laid-Open No. 4-506392 has a structure movable by a bimetal formed by a diaphragm 300 made of silicon and an aluminum thin film 304. A silicon dioxide thin film 306 is inserted between the diaphragm 300 and the aluminum thin film 304 to obtain electrical insulation.

In the semiconductor manufacturing process, the silicon dioxide thin film 306 and the silicon dioxide thin film of the hinge 303 are formed at the same time, and it is desirable that these films have the same thickness. However, the diaphragm 300 and the aluminum thin film 3
When the thickness of the silicon dioxide thin film 306 inserted between the layers 04 becomes as large as 2 μm, it can be expected that the bimetal characteristic as a driving source will be deteriorated. Literature ("Electric
ally-Activated, Micromachined Diaphram Valves "
Technical Digest IEEE Solid-State Sensor a
nd Actuator Workshop, pp. 65-69, June 1990), the aluminum thin film 304 has a thickness of 5 to 6 μm, and the silicon dioxide thin film 306 having a thickness of 2 μm includes the diaphragm 300 and the aluminum thin film 30.
It can be easily presumed that if inserted between the holes 4, it will be a factor that hinders the deflection of the diaphragm 300 during heating.

In the semiconductor manufacturing process, a silicon dioxide thin film is usually formed at a high temperature of about 1000 ° C. Therefore, considering the thermal expansion coefficient of silicon and silicon dioxide, the silicon diaphragm 300 and the silicon dioxide thin film 30
It is considered that a considerable internal stress is generated between 6.
This internal stress increases as the thickness of the silicon dioxide thin film 306 increases, which causes a reduction in bimetal characteristics. Considering the above points, the silicon dioxide thin film 306 between the diaphragm 300 and the aluminum thin film 304 is as thin as possible (2 × 10 ⁻⁸ m (200 × 10 ⁻⁸ m).
Å)), and the silicon dioxide film of the hinge 303 must be somewhat thick (2 μm). However, forming such a thin film of silicon dioxide requires a very complicated semiconductor manufacturing process. This manufacturing process is not mentioned in the specification of Japanese Patent Publication No. 4-506392.

As an improvement, US Pat. 5,27
1,597 discloses another hinge structure. This is not the silicon dioxide thin film structure as described above, but the silicon dioxide thin film between the hinge portion and the diaphragm-aluminum thin film has the same thickness. In this method, the thin silicon dioxide thin film at the hinge part is thinned, and in order to compensate for the decrease in the strength of the hinge part caused by the thinning, the part of the diaphragm and the silicon frame is used in addition to the hinge, so a part of the diaphragm silicon is used, so the thermal insulation effect And the power consumption of the semiconductor microactuator is not reduced. As described above, many problems still remain in the heat insulating structure of the semiconductor microactuator.

As a conventional example of a semiconductor microvalve, there is a microminiature valve described in Japanese Patent Laid-Open No. 5-187574. Also in this microminiature valve, at least two materials having different coefficients of thermal expansion are combined,
A semiconductor microactuator that heats the portion and obtains a displacement using a difference in thermal expansion coefficient is used. The thermal insulation structure of this microactuator is performed by providing a torsion bar type suspension.
This structure minimizes heat loss to the silicon frame by both reducing the cross section perpendicular to the heat flow and increasing the path length through which the heat flow passes. However, this torsion
Since the bar-type suspension structure is formed of silicon, it is considered that a sufficient thermal insulation effect cannot be obtained as considered in the calculation of heat escape.

This is described in the document "SILICON MICROVALVES FOR
GAS FLOW CONTROL '' The 8th International Conference
on Solid-State Sensor and Actuators, Stockholm, Swe
Den, 1995, pp. 276-279, can be estimated from the microvalve performance comparison table. In this document, Japanese Translation of PCT Publication No. 4-5
Microvalve relating to "semiconductor microactuator" disclosed in JP-A-063922
No. 4 discloses a comparison of the bicro valve related to the “ultra-small valve”, and the latter has a pressure resistance of 6 times as compared with the former.
The power consumption is about twice and the thermal resistance is about 1/3, although the flow rate range is 10 times.

As described above, the microminiature valve described in JP-A-5-187574 has a structure capable of generating a large force by a torsion bar type suspension structure made of silicon, but consumes a large amount of power. turn into.

Further, as conventional examples of semiconductor microrelays, Japanese Patent Application Laid-Open No. 6-338244 and Japanese Patent Application Laid-Open No.
No. 3 discloses this. The semiconductor microrelay shown in these will be described with reference to the drawings.

FIG. 55 is a sectional view showing the structure of a conventional semiconductor microrelay. As shown in FIG. 55, a cantilever beam 313 made of a silicon single crystal substrate 312 having a first coefficient of thermal expansion and having one end supported to be movable is provided. A metal layer 316 having a second coefficient of thermal expansion larger than the first coefficient of thermal expansion is provided on the back side of the cantilever beam 313 via a conductive layer 315. On the main surface of the cantilever beam 313, a contact circuit 317 is provided on one end side via an oxide film 314. A heater circuit 318 is provided on substantially the entire main surface of the cantilever beam 313 via an oxide film 314.

On the other hand, above the contact circuit 317, an opposing contact portion 320 having a conductive layer 319 on the opposing surface is provided at a position facing the intermediary of a predetermined space. The heater circuit 318 is heated by passing a current through the heater circuit 318. Thereby, the cantilever beam 313 and the metal layer 3
The flexible region consisting of 16 is heated. At this time, since the coefficient of thermal expansion of the metal layer 316 is set to be larger, the cantilever beam 313 and the metal layer 316 are displaced upward. Therefore, the contact circuit 317 provided at one end of the cantilever beam 313 is pressed against the opposing contact portion 320 to be in a conductive state. Such a bimetal-driven relay can increase a contact interval and a contact load as compared with a conventional electrostatic drive relay. Therefore, a highly reliable relay with low contact resistance and little welding can be realized.

However, the conventional semiconductor micro relay has the following problems. To drive a relay,
An electric current is applied to a heater circuit 318 provided on the main surface of the cantilever beam 313 to cause the cantilever beam 313 and the metal layer 31 to pass through.
6 need to be heated. However, the silicon single crystal forming the cantilever beam 313 is a material having a very good thermal conductivity, and the other end of the cantilever beam 313 is connected to the silicon single crystal substrate 312. Is large, and it becomes very difficult to raise the temperature of the cantilever beam 313 with low power consumption.

FIG. 56 shows a model of heat conduction.
The broken line is assumed to be a cross section of the cantilever beam 313. Using this model, heat release (in the direction of the arrow) to the silicon single crystal substrate 312 is roughly calculated as follows. First, the size of the cantilever beam 313 is 1.5 mm × 1.5 m.
m, and the thickness is 10 μm, the cross section A3 perpendicular to the direction of the heat flow is: A3 = 10 μm (thickness) × 1500 μm (width) = 1.5
It becomes 0 × 10 ⁻⁴ cm ² . The thermal conductivity λ of silicon is λ = 1.48 W / cm
If the temperature of the cantilever beam 313 at the time of heating is 250 ° C., the amount of heat Q3 escaping to the silicon single crystal substrate 312 can be calculated by using the above-mentioned formula X, Q3 = 1.48 (W / cm · ° C.) × (250 (° C) / 2
80 × 10 ⁻⁴ (cm)) × 1.50 × 10 ⁻⁴ (cm ² )
= 1.98 (W). That is, in the conventional semiconductor microrelay, approximately 2 W of power must be constantly supplied in order to maintain the conductive state. This is a very large value compared to a mechanical relay that can be driven at several tens of mW, and low power consumption is a major issue in practical use.

[0021]

As described above, a semiconductor microactuator using a conventional semiconductor device,
Since the semiconductor microvalve and the semiconductor microrelay require large power consumption, it is difficult to be driven by a battery, and they cannot be miniaturized or used in a portable state.

The present invention has been made in view of the above circumstances, and a purpose thereof is to provide a semiconductor device which consumes low power and has a simple manufacturing process, and a semiconductor microactuator, a semiconductor microvalve, and a semiconductor microrelay using the same. And a method of manufacturing a semiconductor microactuator.

[0023]

In order to solve the above-mentioned problems, the invention according to claim 1 includes a semiconductor substrate, a flexible region displaced with respect to the semiconductor substrate due to a temperature change, the semiconductor substrate and the flexible substrate. And a resin heat insulating region provided between the semiconductor substrate and the flexible region. The resin heat insulating region connects the semiconductor substrate and the flexible region. By providing the space between the flexible regions, heat can be prevented from escaping when the temperature of the flexible region is changed, so that power consumption can be suppressed and the manufacturing process thereof is simple.

According to a second aspect of the present invention, in the first aspect of the present invention, the material constituting the heat insulating region has a thermal conductivity of about 0.4 W / (m · ° C.) or less. As a feature, the thermal insulation between the flexible region and the semiconductor substrate is improved.

According to a third aspect of the present invention, in the second aspect, the material constituting the heat insulating region is polyimide, and the flexible region and the semiconductor substrate have good heat insulating properties. At the same time, manufacturing becomes easier.

According to a fourth aspect of the present invention, in the second aspect, the material forming the heat insulating region is a fluorinated resin, and the heat insulating property between the flexible region and the semiconductor substrate is reduced. And the manufacture becomes easier.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the reinforcing layer made of a material harder than the material forming the heat insulating region is provided in the heat insulating region. It is characterized by being provided, so that the connection strength between the semiconductor substrate and the flexible region can be increased.

According to a sixth aspect of the present invention, in the fifth aspect, the reinforcing layer has a Young's modulus of 9.8 × 10
It is characterized by being ⁹ N / m ² or more, and can increase the connection strength between the semiconductor substrate and the flexible region.

According to a seventh aspect of the present invention, in the sixth aspect of the invention, the reinforcing layer is a silicon dioxide thin film, and the connection strength between the semiconductor substrate and the flexible region can be increased. .

According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, the portions of the semiconductor substrate and the flexible region which are in contact with the heat insulating region have a comb-like shape. Thus, the connection strength between the semiconductor substrate and the flexible region can be increased.

According to a ninth aspect of the present invention, there is provided the semiconductor device according to any one of the first to eighth aspects, and a movable element connected to the flexible region, wherein a temperature of the flexible region is increased. Wherein the movable element is displaced with respect to the semiconductor substrate when is changed. In addition to being drivable with low power consumption, the same effect as in the inventions of claims 1 to 8 is obtained. Is obtained.

According to a tenth aspect of the present invention, in the ninth aspect, the flexible region has a cantilever structure, and the semiconductor microactuator having a large displacement of the movable element is provided. can get.

The eleventh aspect of the present invention is characterized in that, in the ninth aspect, the movable element is supported by a plurality of flexible regions, and the movable element can be stably supported.

According to a twelfth aspect of the present invention, in the eleventh aspect, the flexible region has a cross shape with the movable element interposed therebetween, and the movable element has a good displacement accuracy. Becomes

According to a thirteenth aspect, in the eleventh aspect, the displacement of the movable element includes a displacement that rotates in a horizontal direction with respect to a substrate surface of the semiconductor substrate. The displacement of the movable element becomes large.

According to a fourteenth aspect of the present invention, in the eleventh or thirteenth aspect, the flexible region has four L-shaped flexible regions centered on the movable element. It is characterized by being provided at equal intervals in four directions, so that the length of the flexible region can be increased, and therefore, the displacement of the movable element can be increased.

According to a fifteenth aspect of the present invention, in the invention according to any one of the ninth to fourteenth aspects, the flexible region comprises at least two regions having different coefficients of thermal expansion. The displacement of the flexible region can be obtained by changing the temperature of the flexible region.

According to a sixteenth aspect, in the fifteenth aspect, the flexible region includes a region made of silicon and a region made of aluminum. Due to the temperature change of the flexible region, displacement of the flexible region due to a difference in thermal expansion between aluminum and silicon can be obtained.

According to a seventeenth aspect, in the fifteenth aspect, the flexible region includes a region made of silicon and a region made of nickel. Due to the temperature change of the flexible region, displacement of the flexible region due to a difference in thermal expansion between nickel and silicon can be obtained.

The invention of claim 18 is characterized in that, in the invention of claim 15, at least one of the regions constituting the flexible region is made of the same material as the heat insulating region. Since the flexible region and the heat insulating region can be formed at the same time, the manufacturing process can be simplified and the cost can be reduced.

According to a nineteenth aspect of the present invention, in the invention according to the eighteenth aspect, the flexible region has a region made of silicon, and the polyimide is used as a region made of the same material as the heat insulating region. 19. An area to be provided,
In addition to the same effects as described above, the displacement of the flexible region due to the difference in thermal expansion between silicon and polyimide can be obtained by the temperature change of the flexible region, and the thermal insulation of the flexible region is also improved by polyimide.

According to a twentieth aspect of the present invention, in accordance with the eighteenth aspect of the present invention, the flexible region has a region made of silicon, and the flexible region is made of fluorine as a region made of the same material as the heat insulating region. And a displacement of the flexible region due to a difference in thermal expansion between the silicon and the fluorinated resin due to a temperature change of the flexible region, in addition to the same effects as those of claim 18. And the fluorinated resin improves the thermal insulation of the flexible region.

According to a twenty-first aspect of the present invention, in any one of the ninth to fourteenth aspects, the flexible region is made of a shape memory alloy. The displacement of the flexible region can be obtained by the temperature change.

According to a twenty-second aspect of the present invention, in any one of the ninth to twenty-first aspects, the flexible region and the movable element are connected between the flexible region and the movable element. Characterized in that a heat insulating region made of a resin is formed, and the heat insulation of the flexible region and the movable element can be ensured, and power consumption when the temperature of the flexible region is changed can be further suppressed. Can be.

According to a twenty-third aspect of the present invention, in the twenty-second aspect, the rigidity of a heat insulating region provided between the semiconductor substrate and the flexible region, and the rigidity of the flexible region and the movable element It is characterized in that the rigidity of the heat insulating region provided therebetween is made different, and the direction of displacement of the movable element can be determined by the difference in rigidity of each heat insulating region.

According to a twenty-fourth aspect of the present invention, in any one of the ninth to twenty-third aspects, a heating means for heating the flexible region is provided. Thus, the temperature of the flexible region can be changed.

According to a twenty-fifth aspect of the present invention, in the invention according to any one of the ninth to twenty-fourth aspects, a wiring for supplying electric power to a heating means for heating the flexible region is provided in the heat insulating region. This is characterized in that it is formed without interposing, and the thermal insulation distance of the wiring can be increased, and the thermal insulation of the flexible region can be improved.

According to a twenty-sixth aspect of the present invention, in any one of the ninth to twenty-fifth aspects, the movable element has a concave portion, and the heat capacity of the movable element is reduced. By reducing the size, the temperature change of the flexible region can be accelerated.

According to a twenty-seventh aspect of the present invention, in any one of the ninth to twenty-sixth aspects, a connecting portion between the flexible region and the movable element or a connecting portion between the flexible region and the semiconductor substrate. In the vicinity of the part, it is characterized by being provided with roundness to relieve stress, and when the flexible region is displaced, the stress applied near the connection part is dispersed by the roundness, so that the part is broken. Can be prevented.

According to a twenty-eighth aspect of the present invention, in the twenty-seventh aspect, the semiconductor substrate is provided with a protruding portion protruding toward a connection portion with the flexible region. The semiconductor substrate is formed at both ends of the base end of the protrusion so that the shape of the semiconductor substrate on the substrate surface becomes an R shape, and when the flexible region is displaced, both ends of the base end of the protrusion are formed. By dispersing the applied stress by rounding, it is possible to prevent that portion from being broken.

According to a twenty-ninth aspect of the present invention, in the method of manufacturing a semiconductor microactuator according to the twenty-seventh aspect, the semiconductor substrate is etched from the substrate surface to form a concave portion, and the bottom portion is formed as the flexible region, Forming a sacrifice layer at the boundary between the bottom surface and the side surface of the concave portion and removing the sacrifice layer by etching to form an R shape, thereby forming the roundness. The roundness can be formed by utilizing the isotropic property. Further, when the flexible region is displaced, the stress applied to the boundary between the bottom surface and the side surface of the concave portion is dispersed by the roundness, so that the portion is broken. Can be prevented.

According to a thirtieth aspect of the present invention, there is provided the semiconductor microactuator according to any one of the ninth to twenty-ninth aspects, wherein the semiconductor microactuator is connected to the semiconductor microactuator, and the fluid amount flowing according to the displacement of the movable element is And a fluid element having a variable flow path. The semiconductor microvalve has the same effects as those of the ninth to twenty-ninth aspects in addition to being drivable with low power consumption. can get.

Further, the invention of claim 31 is characterized in that, in the invention of claim 30, the semiconductor microactuator and the fluid element are joined by anodic bonding, so that both can be joined. .

A thirty-second aspect of the present invention is characterized in that, in the thirty-third aspect, the semiconductor microactuator and the fluid element are joined by eutectic joining. Become.

A thirty-third aspect of the present invention is the liquid crystal display device according to the thirty-third aspect, wherein the semiconductor microactuator and the fluid element are joined via a spacer layer. The difference in thermal expansion between the two when the elements are joined can be absorbed by the spacer layer, and the stress applied to the flexible region can be suppressed.

According to a thirty-fourth aspect of the present invention, in the thirty-third aspect of the present invention, the spacer layer is made of polyimide, and a difference in thermal expansion between the semiconductor microactuator and the fluid element when the two are joined. The stress applied to the flexible region can be suppressed by absorbing the elasticity of the polyimide.

According to a thirty-fifth aspect of the present invention, there is provided the semiconductor micro-actuator according to any one of the ninth to twenty-ninth aspects, wherein the movable element is provided with a movable contact,
It has a fixed element that has a fixed contact capable of contacting the movable contact at the corresponding position and is fixed to the semiconductor microactuator, in addition to being drivable with low power consumption, A semiconductor micro relay having the same effects as the inventions of claims 9 to 29 can be obtained.

According to a thirty-sixth aspect of the present invention, in the thirty-fifth aspect of the present invention, the fixed contact is a separated contact which is in contact with the movable contact to conduct with each other via the movable contact. As a result, a semiconductor micro relay capable of conducting the fixed contacts separated from each other can be obtained.

According to a thirty-seventh aspect, in the thirty-fifth or thirty-sixth aspect, the movable contact and the fixed contact are made of gold cobalt, and conduction between the movable contact and the fixed contact is established. It is possible.

According to a thirty-eighth aspect of the present invention, in any one of the thirty-fifth to thirty-seventh aspects, the semiconductor microactuator and the fixed element are joined by anodic joining. Both can be joined.

According to a thirty-ninth aspect of the present invention, in any one of the thirty-fifth to thirty-seventh aspects, the semiconductor microactuator and the fixing element are joined by eutectic joining. Thus, both can be joined.

According to a forty-third aspect of the present invention, in any one of the thirty-fifth to thirty-seventh aspects, the semiconductor microactuator and the fixing element are joined via a spacer layer. In addition, the difference in thermal expansion between the semiconductor microactuator and the fluid element when the fluid element is joined can be absorbed by the spacer layer, and the stress applied to the flexible region can be suppressed.

According to a forty-first aspect of the present invention, in the forty-ninth aspect, the spacer layer is made of polyimide, and a difference in thermal expansion between the semiconductor microactuator and the fluid element when the two are joined. The stress applied to the flexible region can be suppressed by absorbing the elasticity of the polyimide.

According to a twenty-second aspect of the present invention, in the method of manufacturing a semiconductor microactuator according to the eighteenth aspect, one surface of the semiconductor substrate is removed by etching so that the bottom surface is formed of one of the flexible regions. A step of forming the concave portion of the movable element by etching and removing the other surface of the semiconductor substrate at the same time as forming the region, and removing the other surface of the semiconductor substrate by etching to form at least the semiconductor substrate and the flexible substrate. Forming a portion to be the heat insulating region provided between the bending regions; and embedding a heat insulating material in the portion to be the heat insulating region to form the heat insulating region and simultaneously applying the heat insulating material to the semiconductor substrate. 1 to form the flexible region by applying to the other surface of
It is characterized by having a step of forming one region, and by simultaneously forming the heat insulating region and one region constituting the flexible region with the same material, the manufacturing process is simplified,
Cost can be reduced.

According to a forty-third aspect of the present invention, in the method of manufacturing a semiconductor microactuator according to the sixteenth aspect, one surface of the semiconductor substrate is removed by etching so that the bottom surface is formed of one of the flexible regions. A step of forming the concave portion of the movable element by etching and removing the other surface of the semiconductor substrate at the same time as forming the region, and removing the other surface of the semiconductor substrate by etching to form at least the semiconductor substrate and the flexible substrate. Forming a portion to be the heat insulating region provided between the flexible regions, forming an aluminum thin film on the other surface of the semiconductor substrate, a region formed of aluminum in the flexible region, Forming a wiring for supplying power to the heating means, and embedding a heat insulating material in a portion to be the heat insulating region to form the heat insulating region It is characterized by having a degree, and a region composed of aluminum of the flexible region,
By simultaneously forming wiring for supplying electric power to the heating means, the manufacturing process can be simplified and the cost can be reduced.

According to a forty-fourth aspect of the present invention, in the method of manufacturing a semiconductor microactuator according to the seventeenth aspect, one surface of the semiconductor substrate is removed by etching so that the bottom surface is formed of one of the flexible regions. A step of forming the concave portion of the movable element by etching and removing the other surface of the semiconductor substrate at the same time as forming the region, and removing the other surface of the semiconductor substrate by etching to form at least the semiconductor substrate and the flexible substrate. Forming a portion serving as the heat insulating region provided between the bending regions; forming a wiring for supplying power to the heating means; and embedding a heat insulating material in the portion serving as the heat insulating region. Forming a heat insulating region, and forming a nickel thin film on the other surface of the semiconductor substrate as a region composed of nickel of the flexible region. And characterized by a step of, it can provide a region composed of nickel flexible area.

According to a forty-fifth aspect of the present invention, in the method for manufacturing a semiconductor device according to the first aspect, at least one surface of the semiconductor substrate is removed by etching to be provided at least between the semiconductor substrate and the flexible region. Forming a portion to be the heat insulating region, embedding a heat insulating material in the portion to be the heat insulating region, and forming the heat insulating region by etching away the other surface of the semiconductor substrate. And a heat insulating region can be formed between the semiconductor substrate and the flexible region.

According to a forty-sixth aspect of the present invention, in the method for manufacturing a semiconductor device according to the fifth aspect, at least one surface of the semiconductor substrate is removed by etching to be provided at least between the semiconductor substrate and the flexible region. Forming a portion to be the heat insulating region, forming a layer to be a reinforcing layer in the heat insulating region, embedding a heat insulating material in the portion to be the heat insulating region, and the other of a semiconductor substrate Forming a heat insulating region by etching away the surface of the semiconductor substrate, forming a heat insulating region between the semiconductor substrate and the flexible region, and forming a reinforcing layer in the heat insulating region. be able to.

According to the present invention, a resin material such as polyimide or fluorinated resin has a high thermal insulation property (about 80% of silicon dioxide).
Times), and is easily processed in a liquid state and has a desired thickness (several μm to several tens μm) by a semiconductor manufacturing process such as spin coating.
The focus is on the feature that the thin film of m) can be easily obtained.

[0070]

(Embodiment 1) Embodiment 1 of the present invention will be described. FIG. 1 is a partially cutaway perspective view showing the structure of a semiconductor microactuator using a semiconductor device according to the present invention, FIG. 2 (a) is a sectional view, and FIG. 2 (b) is a top view.

As shown in the figure, a semiconductor microactuator 1 is composed of a semiconductor substrate 3 which is a hollow and substantially rectangular frame, and is thermally insulated inward from a substantially center of each side of the semiconductor substrate 3 separated from the semiconductor substrate 3. Four thin-walled portions 2S each having a substantially square piece shape, one end of which is connected via the region 7; and a hollow truncated pyramid shape whose upper surface is opened in a square shape and whose width becomes narrower downward. A movable element 5 having an upper peripheral edge connected to the other end of the portion 2S; and an aluminum thin film or a nickel thin film provided on the upper surface of each of the thin portions 2S and forming the flexible region 2 together with the thin portion 2S. It is composed of a thin film 2M.

The semiconductor substrate 3, the thin portion 2S, and the movable element 5 are formed by processing a semiconductor substrate such as a silicon substrate. On the surface of the thin portion 2S, an impurity diffusion resistor 6 (hereinafter referred to as a diffusion resistor 6) as a heating means is formed. The diffusion resistor 6 is connected to the electrode pads 4 provided at the four corners of the semiconductor substrate 3. Connected wiring 4
The power is supplied by a and the temperature rises to heat the flexible region 2 composed of the thin portion 2S and the thin film 2M. As described above, the thin film 2M is made of aluminum or nickel, and the thin portion 2S is made of silicon or the like, and both have different thermal expansion coefficients.

The heat insulating region 7 connecting the semiconductor substrate 3 and the flexible region 2 has substantially the same thickness as the thin portion 2S and is made of a heat insulating material such as a fluorinated resin or polyimide. And the flexible region 2 are thermally insulated. The electrode pads 4 provided at the four corners of the semiconductor substrate 3 are such that the upper right electrode pad 4 and the lower left electrode pad 4 in FIG. A series circuit is connected in parallel.

The four flexible regions 2 have a cross shape with the central movable element 5 interposed therebetween, and the movable element 5 is structured so that its periphery is supported by the plurality of flexible regions 2. . Here, the semiconductor device 8 is composed of the semiconductor substrate 3, the flexible region 2, and the heat insulating region 7 between them.

The semiconductor microactuator 1 is
When power is applied to the diffusion resistor 6, the temperature rises and the flexible region 2
Is heated, and the thin film 2M and the thin portion 2 forming the flexible region 2 are formed.
Thermal stress occurs due to the difference in the thermal expansion coefficient of S. For example, when a metal thin film of aluminum, nickel, or the like is formed as the thin film 2M, the flexible region 2 is bent downward in the drawing because the thin film portion 2S has a larger thermal expansion coefficient than silicon. That is, the flexible region 2 is displaced downward with respect to the semiconductor substrate 3. And the flexible region 2
The movable element 5 is continuously displaced downward with respect to the semiconductor substrate 3 due to the thermal stress of the flexible region 2.

As described above, the semiconductor microactuator 1 has the movable element 5 having four flexible regions at the center.
, The displacement of the movable element 5 is a non-rotational displacement with respect to the semiconductor substrate 3, and a large force can be generated with good displacement control accuracy. Further, as described above, the flexible region 2 has a flexible region 2 on its surface.
Is provided, that is, since the flexible region 2 includes the diffusion resistor 6, the semiconductor microactuator 1 can be downsized.

Although the semiconductor microactuator 1 of the present embodiment is constituted by the thin portion 2S and the thin film 2M which are two regions having different thermal expansion coefficients as the flexible region 2, the present invention is not limited to this. For example, the flexible region 2 may be made of a shape memory alloy such as nickel titanium, and the flexible region 2 made of the shape memory alloy may be displaced by a temperature change.

The present invention is not limited to a semiconductor microactuator, but may be a temperature sensor that measures displacement of a flexible region due to a temperature change using a laser displacement meter or the like and detects a temperature according to the displacement. Since the heat insulating region 7 is provided between the flexible region 2 and the semiconductor substrate 3,
Any semiconductor device may be used as long as it has an effect of preventing heat generated when heating the flexible region from escaping to the semiconductor substrate 3.

Here, in order to explain the operation of the semiconductor device 8 used in the semiconductor microactuator 1 of the present invention, as shown in the sectional view of FIG. Consider the case where the length of the region 2 in the connection direction is 30 μm, the thickness is 20 μm, and polyimide (trade name “Photo Nice”, hereinafter referred to as polyimide) is used as a constituent material. FIG.
The length of the flexible region 2 shown in FIG.
m, and the width of the flexible region 2 (the length in the direction orthogonal to the connection direction) is 600 μm.

When the amount of heat Q3 escaping from the flexible region 2 to the semiconductor substrate 3 through the heat insulating region 7 is calculated, it follows the formula X shown in the conventional example. Here, the cross section A10 perpendicular to the direction of the heat flow of the escaped heat is: A10 = (thickness of polyimide) × (width of flexible region) = 2
0 μm × 600 μm = 1.2 × 10 ⁻⁴ cm The thermal conductivity of polyimide is 1.17 × 10
⁻³ (W / cm ° C.) and the distance δ from the heat source, that is, the distance between the flexible region 2 and the semiconductor substrate 3 is 30 μm.
The amount of heat Q3 escaping from the flexible region 2 heated to 150 ° C. to the semiconductor substrate 3 is Q3 = 1.17 × 10 ⁻³ (W / cm · ° C.) × (150 ° C.)
/ (30 × 10 ⁻⁴ cm)) × 1.2 × 10 ⁻⁴ (cm ² )
= 4.2 × 10 ⁻³ (W) = 4.2 (mW). As described above, since the semiconductor device 8 has the four flexible regions 2, the total amount of heat is 16.8 mW. This indicates that the temperature of the flexible region 2 can be maintained at 150 ° C. by supplying the input power of 16.8 mW to the diffusion resistor 6, which is smaller than the conventional example of 660 mW.
Power consumption can be reduced to 1/40.

Next, the strength of the heat insulating region 7 made of polyimide will be considered. A model of a doubly supported beam structure fixed at both ends shown in FIG. When a load W is applied to the center of the beam 21 (corresponding to the flexible region 2) from below as shown in FIG. 4A, the shear force and the moment force of the beam 21 are respectively shown in FIG. The result is as shown in FIG.
In FIG. 4A, the heat insulating region 7 is located at any one of between the fixed ends 22 a and 22 b at both ends and the beam 21. Thus, for example, when a load W of 1 g is applied to the center of the beam 21 (in the case of a micro valve, the orifice 500 μm is used).
m corresponds to a pressure of 46.7 kPa)
The force applied to the beam 21 at is calculated.

The shear force F1 applied to the beam is F1 = W / 2 =
1.0 × 10 ⁻³ (kgf) /2=0.5×10 ⁻³ (kg
f) = 4.9 × 10 ⁻³ (N), and the maximum shear stress Fmax applied to the beam is as follows: Fmax = F1 / S1 (S1 is the cross-sectional area of the beam). Here, the width b1 of the beam 21 = 600 μm,
If the thickness h1 is 20 μm, the sectional area S1 is: S1 = (b1) (h1) = 600 × 10 ⁻⁴ × 20 × 10
^-4 = 1.2 × 10 ^-4 cm ² . Therefore, the maximum shear stress Fma applied to the beam 21
x is: Fmax = 0.50 × 10 ⁻³ (kgf) /1.2×10
^-4 (cm ² ) = 4.16 (kgf / cm ² ) = 4.16 ×
0.098 (MPa) = 0.41 (MPa). Next, the maximum stress σmax applied to the beam 21 is determined. The maximum stress σmax is represented by σmax = Mmax / Z1. At this time, Mmax is the maximum moment, and Z1 is the section modulus. As shown in FIG. 4C, the maximum moment Mmax is Mmax = WL / 8 (L is the length of the beam is 800 μm). Therefore, the maximum moment Mmax is Mmax = WL / 8 = 1.0 × 10 ^{−. 3} (k
gf) × 800 × 10 ⁻⁴ (cm) /8=1.0×10 ⁻⁵
(Kgf · cm) = 9.8 × 10 ⁻⁵ (N · cm). Moreover, the section modulus Z1 is Z1 = (b1) (h1) 2/6 = 1/6 × 600 × 10
⁻⁴ × (20 × 10 ⁻⁴ ) ² = 4.0 × 10 ⁻⁸ (cm ³ ). Then, the maximum stress σmax due to the moment is σmax = Mmax / Z = 1.0 × 10 ⁻⁵ (kgf · c
m) /4.0×10 ⁻⁸ (cm ³ ) = 250 (kgf / c)
m ² ) = 24.5 (MPa). Here, as described above, the size of the beam 21 is
It was determined as 00 μm and 800 μm in length.

Since the breaking strength of polyimide is about 30 MPa, a semiconductor microactuator capable of withstanding a load of about 1 g in the above-mentioned heat insulating region 7 can be realized. The strength of the heat insulating region 7 can be increased as shown in another example. Although not described here, the same effect can be expected with a fluorinated resin.

Here, an example of a method of forming the heat insulating region 7 is shown in FIG.
This will be described with reference to FIG. First, as shown in FIG. 5A, a portion corresponding to a heat insulating region on the surface of the semiconductor substrate 17 is KOH
The groove 15 is formed by etching using, for example, this method. afterwards,
As shown in FIG. 5B, a polyimide thin film 16 is spin-coated with a coater or the like to form the groove 15 completely. Next, as shown in FIG. 5C, patterning is performed so that the polyimide thin film 16 is completely removed from the portion where the groove 15 is completely filled by a photolithography process of a semiconductor, and the other portions are removed. The organic solvent or the like contained in the polyimide is evaporated and solidified. Next, FIG.
As shown in (d), etching is performed from the back surface of the semiconductor substrate 17 using KOH or the like. At this time, reference numeral 19 denotes a semiconductor substrate serving as a frame, and reference numeral 20 denotes a flexible region. Through these steps, the heat insulating region 7 is formed.

As described above, the heat insulating region 7 is made of a resin material such as polyimide, fluorinated resin or the like having a high heat insulating property (heat conductivity: 0.4 W / (m · ° C.) or less;
Times), and is easily processed in a liquid state and has a desired thickness (several μm to several tens μm) by a semiconductor manufacturing process such as spin coating.
m) is formed between the flexible region 2 and the semiconductor substrate 3 by making good use of the property that the thin film of m) can be easily obtained. The device can be easily realized using a semiconductor manufacturing process. Further, as described above, by making the heat insulating region 7 approximately the same thickness as the thin portion 2S of the flexible region 2, the semiconductor substrate 3
And the flexible region 2 can be reliably connected, and the strength of the connection portion can be increased.

The semiconductor microactuator 1 using the semiconductor device 8 having such an effect has a simple manufacturing process, and has a high thermal insulating property, so that heat generated by the diffusion resistor 6 is prevented from escaping, thereby reducing power consumption. Since it can be driven by electric power and can be driven by a battery, miniaturization is possible.

Next, another configuration example of the semiconductor device 8 will be described. The semiconductor device 8 of this configuration example is shown in FIGS.
As shown in (b), the point that a heat insulating region 7 made of a heat insulating material such as a fluorinated resin or polyimide is formed between the semiconductor substrate 3 and the flexible region 2 is the same as FIG. For example, a silicon dioxide thin film (Young's modulus: 9.8 × 1) is formed on the lower surface (the surface orthogonal to the thickness direction) of the heat insulating region 7.
( ⁹ N / m ² or more) in that a reinforcing layer 12 made of a material harder than the material constituting the heat insulating region 7 is provided. 6 (a) is a sectional view, FIG. 6 (b) is a top view, and FIG. 7 is a sectional view taken along line YY 'of FIG. 6 (b).

As shown in FIG. 7, the specific dimensions are as follows: the heat insulating region 7 has a thickness of 19 μm, and the reinforcing layer 12 has a thickness of 1 μm.
m thickness. As shown in FIG. 6A, the length of the heat insulating region 7 in the connecting direction between the semiconductor substrate 3 and the flexible region 2 is 30 μm, and the length in the YY ′ direction, that is, the depth direction is 600 μm. . Here, when polyimide is used as the material forming the heat insulating material region 7 and silicon dioxide is used as the material forming the reinforcing layer 12, the strength of the heat insulating region 7 in FIG. It is performed under the same conditions as the calculation.

When the Young's modulus of each constituent material of the heat insulating region 7 and the reinforcing layer 12 is E _i , and the cross-sectional area of the cross section shown in FIG. 7 of each region is A _i , the distance from the bottom surface to the neutral axis is ηa. It is given by the following equation.

[0090]

(Equation 1)

The values obtained for the silicon dioxide constituting the reinforcing layer 12 are as follows.

[0092]

(Equation 2)

Further, the respective values of the polyimide constituting the heat insulating material 7 are obtained as follows.

[0094]

(Equation 3)

Here, when the distance ηa to the neutral axis is obtained using the above values, the following is obtained.

[0096]

(Equation 4)

Next, the second moments I _s and _If about the neutral axis of silicon dioxide and polyimide are obtained as follows.

[0098]

(Equation 5)

Here, ηi = η−ηa, that is, ηi indicates the distance from the neutral axis. As described in FIG. 4, when a load of 1 g is applied to the center of the beam having both ends fixed, the maximum moment Mmax applied to the beam is as follows: Mmax = 1.00 × 10 ⁻⁵ (kgf · cm) = 9. 8
× 1.00 × 10 ^-5 × 10 ^-2 (N · m) = 9.8 × 10
^-7 (N · m). Calculating the maximum bending stress σsmax of silicon dioxide,

[0100]

(Equation 6)

Here, I _i is the above second moment I _s ,
_If is shown. Also, the maximum bending stress σ of polyimide
Calculation of fmax is as follows.

[0102]

Equation 7

Therefore, the stress applied to the heat insulating region 7 made of polyimide is about one-half that of the example shown in FIG.
Becomes This is apparently equivalent to doubling the intensity. In FIG. 6, the reinforcing layer 12 is provided on the lower surface of the heat insulating region 7, but the same effect can be obtained even on the upper surface as long as the direction is perpendicular to the thickness direction. In addition, when provided on both the upper and lower surfaces, an effect twice as high as when provided on the lower surface and the upper surface can be obtained.

An example of the method of forming the heat insulating region 7 shown in FIG. 6 will be described with reference to FIG. First, FIG.
As shown in (a), a portion corresponding to the heat insulating region on the surface of the semiconductor substrate 17a is etched by KOH or the like to form a groove 15a. Thereafter, as shown in FIG. 8B, a silicon dioxide thin film 18 is formed on the surface of the semiconductor substrate 17a by thermal oxidation or the like. The silicon dioxide thin film 18 is removed by etching or the like except for the surface portion of the groove 15a.

Next, as shown in FIG. 8C, a polyimide thin film 16a is spin-coated with a coater or the like to form a groove 15a.
Is formed so as to fill the space. Further, as shown in FIG. 8D, the groove 15a is formed by a photolithography process of a semiconductor.
Is patterned so as to leave the portion of the polyimide thin film 16a which has filled up all the portions and remove the other portions.
By heating to a certain degree, the organic solvent and the like contained in the polyimide are evaporated and solidified. Next, as shown in FIG.
The semiconductor substrate 17a is etched from the back surface with KOH or the like to form the heat insulating region 7. At this time, 19
a is a semiconductor substrate serving as a frame, and 20a is a flexible region.

Next, still another configuration example of the semiconductor device of the present invention will be described. As shown in the top view of FIG. 9B, the heat insulating region 1 is provided between the semiconductor substrate 3 and the flexible region 2.
0 is provided, and the portions of the semiconductor substrate 3 and the flexible region 2 that are in contact with the heat insulating region 10 form comb blades in the connecting direction of the semiconductor substrate 3 and the flexible region 2 (the direction orthogonal to BB ′). It has a comb blade shape. As shown in FIG. 10 which is a cross-sectional view taken along the line BB ′ of FIG. 9B, the flexible region 2, the semiconductor substrate 3, and the heat insulating region 10 coexist in the direction BB ′. Here, the heat insulating region 10 is made of a fluorinated resin, polyimide, or the like.

In order to calculate the strength of the heat insulating region 10, as a specific example, as shown in FIGS. 9A and 9B, the thickness of the heat insulating region 10 is 20 μm, and the thickness in the direction perpendicular to the BB ′ direction is set. The width is 30 μm. As shown in FIG. 10, the width of each comb blade composed of the flexible region 2 and the semiconductor substrate 3 in the BB ′ direction is 180 μm, and the width of the heat insulating region 10 in the BB ′ direction is 30 μm. The material of the heat insulating region 10 is polyimide, and the semiconductor substrate 3 and the flexible region 2 are made of silicon. For comparison, the strength of the heat insulating region 10 is calculated under the same conditions as the strength calculation of FIG.

In the case of a combination structure of silicon and polyimide as shown in FIG. 10, the Young's modulus of the silicon is E _si , the Young's modulus of the polyimide is E _Ph , the second moment of area of the silicon part is I _Si , and the cross section of the polyimide part is I _Si . Assuming that the next moment is I _Ph , the moment M _Si applied to the silicon portion and the moment applied to the polyimide portion are M _Ph , the following relational expression is obtained.

[0109]

(Equation 8)

[0110]

[Equation 9]

Here, respective values relating to the silicon portion and the polyimide portion are calculated. Young's modulus of silicon E _Si = 0.19
× 10 ¹² (N / m ² ) = 1.9 × 10 ¹² (dyne / c
m ² )

[0112]

(Equation 10)

Therefore, E _Si · I _Si = 1.93 × 106
(Kgf / cm ² ) × 3.6 × 10 ⁻¹¹ (cm 4) = 6.
94 × 10 ⁻⁵ (kgf · cm ² ) = 6.8 × 10 ⁻⁴ N ·
cm ² . The Young's modulus E _{Ph of} polyimide is 500MP
a

[0114]

[Equation 11]

Therefore, E _Ph · I _Ph = 5.10 × 10
³ (kgf / cm ² ) × 4 × 10 ⁻¹² (cm ⁴ ) = 2.04
× 10 ⁻⁸ (kgf · cm ² ) = 2.00 × 10 ⁻⁷ (N ·
cm ² ).

Here, the moment M _Ph applied to the polyimide portion is as follows.

[0117]

(Equation 12)

Here, M _Ph = 2.93 × 10 ⁻⁹ (kgf
Cm) = 2.87 × 10 ⁻⁸ (N · cm).

Similarly, the moment M _Si applied to the silicon portion is as follows.

[0120]

(Equation 13)

Here, M _Si = 9.99 × 10 ⁻⁶ (kgf
Cm) = 9.79 × 10 ⁻⁵ (N · cm).

Therefore, the maximum stress σ applied to the polyimide part
_Ph is as follows.

[0123]

(Equation 14)

Here, Za is a section modulus. Further, the maximum stress σ _Si applied to the silicon portion is obtained as follows.

[0125]

(Equation 15)

Here, Zb is a section modulus.

Therefore, the stress applied to the heat insulating region made of polyimide is about 1/300 as compared with the example shown in FIG.
Becomes This is apparently equivalent to a 300-fold increase in strength. In FIG. 9, the number of comb blades due to the semiconductor substrate 3 and the flexible region 2 is not limited to that shown in FIG. The effect of is obtained. (Embodiment 2) Next, a second embodiment of the present invention will be described. FIG. 11 is a perspective view of a semiconductor microactuator according to the present embodiment, and FIG.
2 (b) shows a top view.

The semiconductor microactuator 1a of this embodiment is different from the embodiment shown in FIGS. 1 and 2 in that a heat insulating region 7A is newly provided between the flexible region 2 and the movable element 5 in this embodiment. The flexible region 2 and the movable element 5 are connected by a heat insulating region 7A.

As described above, by providing the heat insulating region 7A, the heat insulation between the flexible region 2 and the movable element 5 is enhanced, and the heat generated from the diffusion resistor 6 is prevented from escaping to the movable element 5. The heating of the flexible region 2 is effectively performed, and the power consumption can be reduced.

Also, the rigidity of the heat insulating region 7 provided between the semiconductor substrate 3 and the flexible region 2 and the rigidity of the heat insulating region 7A provided between the flexible region 2 and the movable element 5 are made different. , The direction of displacement of the movable element 5 is determined.
For example, the rigidity of the heat insulating region 7 is increased, and the heat insulating region 7A
By lowering the rigidity of the semiconductor substrate 3, the movable element 5 can be displaced downward in the thickness direction of the semiconductor substrate 3 (downward in FIG. 11). it can.

Further, in the present embodiment, the stress applied when the flexible region 2 is displaced near the connecting portion between the flexible region 2 and the semiconductor substrate 3 or near the connecting portion between the flexible region 2 and the movable element 5 is reduced. Rounding is provided.

That is, as shown in FIG. 12 (b), the protruding portion 25 and the flexible region 2 which protrude inward from substantially the center of each side of the semiconductor substrate 3 serving as a frame are formed by a heat insulating region. 7, rounded portions 25a are formed at both ends of the base end of the protruding portion 25 so that the shape of the semiconductor substrate 3 on the substrate surface becomes an R shape. This roundness 2
5a is formed by forming a mask and performing wet etching or the like.

As shown in FIG. 12A, the thin portion 2S constituting the flexible region 2 is formed on the bottom surface of the recess 27 by forming a recess 27 from the lower surface side of the semiconductor substrate 3 in the figure. The boundary between the bottom surface 27a and the side surface 27b of the recess 27
The roundness 28 is formed to have a shape.
The concave portion 27 is provided by etching from the substrate surface of the semiconductor substrate. For example, by forming a sacrificial layer on the boundary of the concave portion 27 and removing the sacrificial layer by etching,
The roundness 28 is formed by utilizing the isotropic property when the sacrificial layer is diffused.

By forming the rounded portions 25a and 28 in this manner, the stress generated when the flexible region 2 is displaced is reduced.
The semiconductor substrate 3 is prevented from being destroyed by being dispersed and relaxed by the a and 28. That is, when both ends of the base end of the protruding portion 25 projecting inward from the semiconductor substrate 3 have a shape with a corner (edge), the stress of the flexible region 2 is concentrated on the corner and the semiconductor substrate 3 is cracked. there is a possibility. Similarly, if the boundary between the bottom surface portion 27a and the side surface portion 27b of the concave portion 27 provided for forming the flexible region 2 has a corner shape, the stress of the flexible region 2 is concentrated on the corner and the semiconductor is concentrated. The substrate 3 may crack.

Here, as shown in FIGS. 11 and 12,
FIG. 13 shows another configuration example of a semiconductor microactuator in which a heat insulating region is provided between a flexible region and a semiconductor substrate and between a flexible region and a movable element.
A method for making the same will be described.

As shown, the semiconductor substrate 3a and the flexible region 2a are connected via a heat insulating region 7a, and the flexible region 2a and the movable element 5a are connected via a heat insulating region 7b. . The flexible region 2a includes a thin film 2m and a thin portion 2s having different thermal expansion coefficients, and a diffusion resistor 6a is provided on the surface of the thin portion 2s. Also, a wiring 13a for supplying power to the diffusion resistor 6a
Is connected to a diffusion resistor 6a from an electrode pad (not shown) on the semiconductor substrate 3a through the lower surface of the heat insulating region 7a. 9a and 9b are protective thin films.

A method for manufacturing the semiconductor microactuator will be described with reference to FIG. First, a silicon oxide film 80a is formed on both surfaces of a single crystal silicon substrate 80 by thermal oxidation or the like.
The opening 80b is formed by etching the silicon oxide film 80a provided on the back surface of the single crystal silicon substrate 80 using a photoresist patterned in a predetermined shape as a mask, and forming the opening by plasma ashing or the like. The resist is removed. A gap 80c is formed by etching the formed opening 80b with an aqueous solution of potassium hydroxide (hereinafter referred to as an aqueous solution of KOH) or the like (FIG. 14A). At this time, in addition to the KOH aqueous solution, TMAH (tetramethyl ammonium hydroxide solution), humanrazine aqueous solution, or the like may be used. The same applies to the KOH aqueous solution described below.

Next, after removing the entire surface of the silicon oxide film 80a, boron or the like is deposited and thermally diffused to form a diffusion resistor 6 serving as a heater on the surface of the single crystal silicon substrate 80.
a is formed. Subsequently, a silicon oxide film 81b is formed on both surfaces of the single crystal silicon substrate 80 by thermal oxidation or the like, and a silicon nitride film 81a is formed on each silicon oxide film 81b by low-pressure CVD (FIG. 14B). .

Using the photoresist patterned in a predetermined shape as a mask, the silicon oxide film 81b and the silicon nitride film 81a are etched to form an opening 82, and the photoresist is removed by plasma ashing or the like (see FIG. 14 (c)).

Next, the opening 8 of the single crystal silicon substrate 80
The movable element 5a and the thin portion 2s are formed by etching 2 with a KOH aqueous solution or the like. At this time, in order to obtain a desired thickness of the movable element 5a and a desired thickness of the thin portion 2s, a time difference may be provided between the start of etching from each surface of the single crystal silicon substrate 80. Thereafter, by etching the single crystal silicon substrate 80, the heat insulating regions 7a,
Grooves 83a and 83b for forming 7b are formed. These grooves 83a and 83b are grooves for embedding an organic material such as polyimide in a later step, and are etched so that the bottom thickness thereof is about 10 μm (FIG. 14).
(D)).

Subsequently, the movable element 5a, the thin portion 2s
The surface of the substrate etched to form the substrate is oxidized to form a protective film 84 when plating the substrate (FIG. 14E).

Then, aluminum is formed on the upper surface of the single crystal silicon substrate 80 by sputtering or EB evaporation to form a wiring 13a (aluminum wiring) connected to the diffusion resistor 6a (FIG. 15A).

Next, an organic substance 85 such as polyimide is buried in the grooves 83a and 83b (FIG. 15B). Thus, a structure in which the wiring 13a is formed on the lower surface of the organic substance 85 is obtained. Here, the organic substance 85 such as polyimide is formed only in a predetermined portion using a semiconductor lithography process.

Next, a metal pattern of a predetermined shape is formed on the silicon nitride film 81a (the protective thin film 9a in FIG. 13) on the thin portion 2s by plating or the like to form a thin film 2m (FIG. 1).
5 (c)), the thin portion 2s and the thin film 2m form a bimetal structure which is a driving source of the semiconductor microactuator.

Next, the thin portion 2s is etched from the back surface of the thin portion 2s by RIE or the like to separate the thin portion 2s from the peripheral portion of the single crystal silicon substrate 80 (semiconductor substrate 3a in FIG. 13) and the movable element 5a (FIG. 15). (D)). Thereby, the movable element 5a, the flexible region 2a, and the semiconductor substrate 3a are thermally insulated from each other, and the thermal insulation regions 7a and 7b are provided between them.

By the way, in the configuration example shown in FIG. 13, the wiring 13a is provided on the lower surface of the heat insulating region 7a.
As shown in FIG. 16, the wiring (aluminum wiring) 13b is substantially at the middle between the upper surface and the lower surface of the heat insulating region 7a, that is,
a.

In order to form the wiring 13b in this manner, after forming the protective film 84 shown in FIG.
In the step of embedding the organic substance 85 such as polyimide shown in FIG. 15B into the groove 83a formed in the step (d), the polyimide is buried almost to the center, and the wiring forming step shown in FIG. 15A is performed. The groove 83a may be filled again by the filling step shown in FIG.

Since the wiring 13b is formed inside the heat insulating region 7a as described above, there is an effect of protecting aluminum in a later etching step and the like, and a highly reliable wiring structure can be realized.

In the above-mentioned wiring structure, the wiring may be provided on the upper surface of the heat insulating region (FIG. 12A), and the wiring is made flush with the flexible region, the heat insulating region and the semiconductor substrate. By forming the wiring on the side surface, the level difference of the wiring is reduced as compared with the case where the wiring is provided inside or under the heat insulating region 7a, and there is an effect of preventing disconnection.

In order to form the wiring on the upper surface of the heat insulating region as described above, after the step of forming the protective film 84 shown in FIG. 14E, the groove 83a formed in the step of FIG. FIG.
The polyimide may be embedded in the step of embedding the organic substance 85 such as polyimide shown in FIG. 5B, and then the wiring may be formed on the upper surface of the polyimide in the wiring forming step shown in FIG.

(Embodiment 3) Next, a third embodiment will be described. FIG. 17 is a perspective view showing the structure of the semiconductor microactuator according to the present embodiment, and FIG. 18 is a top view thereof. The difference between the present embodiment and the second embodiment is that in the second embodiment, the wiring 4a for supplying power to the diffusion resistor 6 is connected to the diffusion resistor 6 through the upper part of the heat insulating region 7. In the present embodiment, a fillet portion 29 made of, for example, an organic material is formed at a portion (so-called entry corner portion) extending over the semiconductor substrate 3 and the thin portion 2S of the flexible region 2,
The point is that the wiring 4a is formed through the upper portion of the fillet portion 29. That is, in the present embodiment, the wiring 4 a is formed without interposing the heat insulating region 7.

In this structure, a groove is formed from the upper surface (the surface on which the flexible region 2 is formed) of the semiconductor substrate by, for example, anisotropic etching, and an organic resin (such as polyimide) is poured into the groove. , And after removing by etching until the fillet 29 appears from the back surface of the semiconductor substrate, the wiring 4a can be formed on the upper surface of the fillet 29 by sputtering of aluminum or the like.

Since the wiring 4a is made of a material having very high thermal conductivity such as aluminum, the thermal resistance may be a fraction of that of the heat insulating region 7 made of resin despite its small cross-sectional area. If the wiring 4a is formed in the heat insulating region 7, there is a problem that the heat insulating distance of the wiring 4a cannot be secured, and as a result, the heat insulating performance of the heat insulating region 7 cannot be obtained. In the present embodiment, since the wiring 4a is formed without interposing the heat insulating region 7, the heat insulating distance of the wiring 4a can be increased, the reduction in thermal resistance can be suppressed, and the heat insulating effect can be improved. it can. In addition, the mechanical strength of the heat insulating region 7 is reinforced by the fillet portion 29.

As described above, in the semiconductor microactuator according to the present embodiment, the heat insulation effect is improved and power consumption can be further reduced as compared with the second embodiment.

(Embodiment 4) Next, a fourth embodiment will be described. FIG. 19 is a perspective view showing the structure of the semiconductor microactuator according to the present embodiment, and FIG. 20 is a top view thereof. The difference between the present embodiment and the first embodiment is that in the first embodiment, a substantially square piece 4 of the flexible region 2 is formed.
While the two thin portions 2S have a substantially cross shape with the movable element 5 interposed therebetween, the semiconductor microactuator 31 of the present embodiment has the four thin portions 32S of the flexible region 32 having a substantially L-shape. One end of each thin portion 32S is connected to substantially the center of each side of the upper peripheral edge of the movable element 35 which is opened in a rectangular shape, and each flexible region 32 is located at the center of the movable element 3.
The point is that it has a so-called swastika shape with 5 in between. That is, the thin portions 32S of the flexible region 32 are provided at equal intervals in four directions around the movable element 35. Further, the other end of each thin portion 32S is connected to an end of each side of the semiconductor substrate 33, which is a rectangular frame, via a heat insulating region 37.

The flexible region 32 is the same as the first embodiment in that the flexible region 32 is composed of the thin portion 32S and a thin film 32M made of aluminum, nickel, or the like. The point formed on the surface is the same as in the first embodiment. Electric power is supplied to the diffusion resistor 36 from outside via the electrode pads 34 and the wirings 34 a provided at the four corners of the semiconductor substrate 33. Note that a semiconductor device 38 is configured by the semiconductor substrate 33, the flexible region 32, and the heat insulating region 37.

The semiconductor microactuator 31
In the same manner as in the first embodiment, the flexible region 32 is heated by the temperature rise of the diffusion resistor 36, and the thin portion 32S and the thin film 32M
The flexible region 32 is displaced downward due to the thermal expansion difference (when the thin film 32M has a larger thermal expansion coefficient than the thin portion 32S). When the flexible region 32 is displaced downward, the movable element 35 connected to the flexible region 32
Is displaced downward with respect to the semiconductor substrate 33 due to the thermal stress.

In this embodiment, as described above, since each flexible region 32 has a so-called swastika shape with the central movable element 35 interposed therebetween, the displacement of the movable element 35 is horizontal with respect to the semiconductor substrate 33. Includes rotation. Further, since the flexible region 32 is L-shaped, its length can be made longer than in the case of a simple square piece,
Since the displacement of the flexible region 32 increases, the displacement of the movable element 35 can be increased. Here, the semiconductor device 38 may have any of the configurations shown in FIGS. 3, 6, and 9 described above, and a semiconductor microactuator having the same effects as those described above can be obtained.

(Embodiment 5) Next, a fifth embodiment will be described. FIG. 21 is a perspective view showing the structure of the semiconductor microactuator of the present embodiment, and FIG. 22 is a top view thereof. Semiconductor microactuator 31a of the present embodiment
Is a configuration in which the above-described flexible region 32 has a so-called swastika shape with the movable element 35 interposed therebetween, and a thermal expansion region 37a connecting the movable element 35 and the flexible region 32 is provided therebetween. Is what it is.

As described above, by providing the heat insulating region 37a, the heat insulation between the flexible region 32 and the movable element 35 is enhanced, and the heat generated by the diffusion resistor 36 is prevented from escaping to the movable element 35. Can be. Therefore, compared to the fourth embodiment, the flexible region 32 can be heated more effectively, and the power consumption can be reduced.

Further, in the present embodiment, the stress applied when the flexible region 32 is displaced near the connecting portion between the flexible region 32 and the semiconductor substrate 33 or near the connecting portion between the flexible region 32 and the movable element 35 is reduced. This embodiment is similar to the embodiment shown in FIGS. For example,
As shown in FIG. 22A, R-shaped roundings 39a are formed at both ends of a base end of a protruding portion 39 which protrudes inward from each side end of the semiconductor substrate 33.

(Embodiment 6) Next, a sixth embodiment of the present invention will be described. FIG. 23 is a perspective view showing the structure of the semiconductor microactuator of the present embodiment. The semiconductor microactuator 41 according to the present embodiment includes a semiconductor substrate 43 which is a hollow and substantially rectangular frame, and a heat insulating region 47 separated from one side of the semiconductor substrate 43 by the semiconductor substrate 43.
Substantially square piece-shaped thin portion 42S whose one end is connected via
The thin portion 4 is formed in a hollow truncated pyramid shape in which the upper surface is opened in a square shape and the width decreases downward.
A movable element 45 having an upper peripheral edge connected to the other end of 2S; and a thin film 42M such as an aluminum thin film or a nickel thin film provided on the upper surface of the thin portion 42S and constituting the flexible region 42 together with the thin portion 42S. It consists of.

The semiconductor substrate 43, the thin portion 42S, and the movable element 45 are formed by processing a semiconductor substrate such as a silicon substrate. On the surface of the thin portion 42S, an impurity diffusion resistor 46 (hereinafter referred to as a diffusion resistor 46) as a heating means is formed.
6 is supplied with power by a wiring 44a connected to an electrode pad 44 provided on a semiconductor substrate 43 and connected to an external power supply, the temperature rises, and the flexible region 42 is heated. Thin film 4
2M is made of aluminum or nickel as described above, and the thin portion 42S is made of silicon or the like, and both have different thermal expansion coefficients.

The heat insulating region 47 connecting the semiconductor substrate 43 and the flexible region 42 has substantially the same thickness as the thin portion 42S.
The semiconductor substrate 43 and the flexible region 42 are thermally insulated from a heat insulating material such as a fluorinated resin or polyimide. Here, the semiconductor device 48 is composed of the semiconductor substrate 43, the flexible region 42, and the heat insulating region 47 therebetween. The semiconductor microactuator 41 has a cantilever structure in which a flexible region 42 is supported at one end by a semiconductor substrate 43.

The temperature of the semiconductor microactuator 41 rises when electric power is applied to the diffusion resistor 46, and the flexible region 4
2 is heated, and a thermal stress is generated due to a difference in the thermal expansion coefficient between the thin film 42M and the thin portion 42S constituting the flexible region 42. For example, when a metal thin film of aluminum, nickel, or the like is formed as the thin film 42M, the flexible region 42 is bent downward in the figure because the coefficient of thermal expansion is larger than that of silicon constituting the thin portion 42S. The movable element 45 connected to the flexible region 42 is
, And is displaced downward with respect to the semiconductor substrate 43.

In this embodiment, since the flexible region has a cantilever structure, the flexibility of the flexible region can be increased, and the displacement of the flexible region during heating increases. Therefore, the displacement of the movable element 45 increases, and a large force is obtained. Here, the semiconductor device 48 may have any of the configurations of FIGS. 3, 6, and 9 described in the first embodiment.
A semiconductor microactuator having the same effect can be obtained.

(Embodiment 7) Next, a seventh embodiment will be described. FIG. 24 is a perspective view showing the structure of a semiconductor microactuator 41a of the present embodiment. The present embodiment differs from Embodiment 6 in that polyimide or fluorine in which a flexible region 42 and a movable element 45 are provided therebetween. The point is that they are connected by a heat insulating region 47a made of a resin such as a modified resin.

By newly providing the heat insulating region 47a in this manner, the heat insulation between the flexible region 42 and the movable element 45 is enhanced, and the heat generated from the diffusion resistor 46 is prevented from escaping to the movable element 45. Embodiment 6
Heating of the flexible region 42 can be more effectively performed as compared with the above, and the power consumption can be reduced.

(Embodiment 8) Next, an eighth embodiment of the present invention will be described. FIG. 25 is a perspective view showing the structure of a semiconductor microactuator 41b according to the present embodiment.
Is that the thin portion 47M and the heat insulating region 47 are made of the same material having heat insulating properties (for example, polyimide, fluorinated resin). This makes it possible to simultaneously form the heat insulating region 47 and the thin film 47M, thereby simplifying the manufacturing process.

The movable element 45 of the semiconductor microactuator 41b has a recess 45H formed by dug-down from the upper surface, and the movable element 45 has no recess formed therein (see the semiconductor microactuator shown in FIG. 26). Since the heat capacity of the movable element 45 is smaller than that of the movable element 45a) 41c, the temperature of the flexible region 42 can be rapidly increased. Further, since the weight (volume) of the movable element is reduced by forming the concave portion 45H, there is an advantage that a malfunction does not occur in response to an external impact.

(Embodiment 9) Next, Embodiment 9 of the present invention will be described.
Will be described. FIG. 27 is a partially broken perspective view showing the structure of the semiconductor microvalve in the present embodiment. This semiconductor microvalve is composed of a pedestal 50, which is a fluid element formed by processing a substrate, and an actuator portion joined to the upper portion by anodic bonding, eutectic bonding, or the like. , The flexible region 2 shown in FIGS. 1 and 2 has a cross shape with the movable element 5 interposed therebetween.
Is used.

The pedestal 50 has a through hole 51 (so-called orifice) corresponding to a fluid flow path at a position corresponding to the movable element 5 of the semiconductor microactuator 1 on its surface.
Is provided around the upper surface opening of the through-hole 51, and the base 52 protrudes higher than the periphery and has a substantially planar upper surface.
Are formed. Here, the movable element 5 corresponds to a so-called valve body.

When the power is supplied to the diffusion resistor 6 and the flexible region 2 is heated, the semiconductor microvalve 55 thus configured is displaced due to the difference in thermal expansion between the thin portion 2S and the thin film 2M, and is displaced. The movable element 5 connected to 2 is displaced. Due to the displacement of the movable element 5, the distance between the lower surface of the movable element 5 and the base 52 of the base 50 changes, and the amount of fluid flowing through the through hole 51 is controlled.

Also in the semiconductor microvalve of this embodiment, since the heat insulating region 7 made of a resin such as polyimide is provided between the semiconductor substrate 3 and the flexible region 2,
It is possible to prevent heat at the time of heating the flexible region 2 from escaping to the semiconductor substrate 3. Therefore, it is possible to suppress power consumption in the driving.

Further, since the four flexible regions 2 have a cross shape with the central movable element 5 interposed therebetween, the precision of control of the movable element 5 is good, and a semiconductor microvalve with good fluid control precision can be obtained.

FIG. 28 shows an example in which the actuator portion of the semiconductor microvalve in FIG. 27 is constituted by the semiconductor microactuator 1a shown in FIGS. In the semiconductor microvalve of this configuration example, the pedestal 50 and the semiconductor microactuator 1a are joined via a spacer layer 53 made of polyimide.

Also, a heat insulating region 7A is provided between the flexible region 2 and the movable element 5, so that the heat escaping from the flexible region 2 can be further reduced as compared with the semiconductor microvalve shown in FIG. And power consumption in the driving can be suppressed.

Further, a rounded portion is provided near the connecting portion between the flexible region 2 and the semiconductor substrate 3 or near the connecting portion between the flexible region 2 and the movable element 5 to reduce the stress applied when the flexible region 2 is displaced. 11 and FIG.
This is the same as that described in 2.

Further, since the spacer layer 53 is formed between the base 50 and the semiconductor microactuator 1a, the following effects can be obtained. Usually, the semiconductor microactuator 1a is made of a silicon substrate, and the pedestal 50 is made of a glass substrate. Since the two are bonded at a high temperature (anodic bonding at 400 ° C.), stress is generated between the two at room temperature due to a difference in the degree of shrinkage caused by a difference in thermal expansion between the two. Since this stress concentrates on the flexible region 2 of the semiconductor microactuator 1a, the flexible region 2
Cannot be obtained, and the drivability of the semiconductor microvalve deteriorates. Therefore, a spacer layer 5 is provided between them.
By providing 3, the stress generated between them can be absorbed and reduced as described above.

The operation of the semiconductor microvalve of this configuration example is the same as that of the case of FIG. 27, and a description thereof will be omitted.

FIG. 29 shows an example in which the actuator portion of the semiconductor microvalve in FIG. 27 is constituted by the semiconductor microactuator 1b shown in FIG. The semiconductor microvalve of this configuration example is different from the configuration example shown in FIG. 28 in that the wiring 4a for supplying power to the diffusion resistor 6 for heating the flexible region 2 is formed without passing through the heat insulating region 7. Since the heat insulation distance of the wiring 4a having good thermal conductivity can be increased, a semiconductor microvalve having a higher heat insulation effect can be obtained, and power consumption for driving the semiconductor microvalve can be suppressed.

Note that the operation of the semiconductor microvalve of this configuration example is the same as that of FIG. 27, and a description thereof will be omitted.

(Embodiment 10) Next, a tenth embodiment of the present invention will be described. FIG. 30 is a partially broken perspective view showing the structure of the semiconductor microvalve of the present embodiment. FIG.
The semiconductor microvalve shown in FIG. 0 includes a pedestal 56, which is a fluid element formed by processing a substrate, and an actuator portion joined to the upper portion by anodic bonding, eutectic bonding, or the like. As a part, a semiconductor microactuator 31 in which the flexible region 32 shown in FIGS. 19 and 20 has a so-called swastika shape with the movable element 35 interposed therebetween is used.

The pedestal 56 is provided with a through hole 57 (so-called orifice) corresponding to a fluid flow path at a position corresponding to the movable element 35 of the semiconductor microactuator 31 on the surface thereof. A base 58 projecting higher than the periphery and having a substantially planar upper surface is formed around the part. Here, the movable element 35 corresponds to a valve body.

When the power is supplied to the diffusion resistor 36 and the flexible region 32 is heated, the semiconductor microvalve configured as described above is displaced by the difference in thermal expansion between the thin portion 32S and the thin film 32M, and is displaced. Movable element 3 connected to
5 is displaced. The displacement of the movable element 35 changes the distance between the lower surface of the movable element 35 and the base 58 of the pedestal 56, and controls the amount of fluid flowing through the through-hole 57.

Also in the semiconductor microvalve of the present embodiment, since the heat insulating region 37 made of a resin such as polyimide is provided between the semiconductor substrate 33 and the flexible region 32, when the flexible region 32 is heated. Heat of the semiconductor substrate 33
Can be prevented from escaping. Therefore, it is possible to suppress power consumption in the driving.

In the semiconductor microvalve of this embodiment, the length of the flexible region 32 is long because the flexible region 32 is L-shaped, and the displacement of the flexible region 32 is large. The displacement can be increased. Therefore, the semiconductor microvalve has a wide range of fluid flow control.

Here, FIG. 31 shows an example in which the actuator section in FIG. 30 is constituted by the semiconductor microactuator 31a shown in FIG. 21 and FIG. The semiconductor microvalve of this configuration example includes a flexible region 32 and a movable element 3.
5 are also provided with a heat insulating region 37a.
The heat escaping from the flexible region 32 can be further reduced as compared with the semiconductor microvalve indicated by, and the power consumption in driving the semiconductor microvalve can be suppressed.

A rounded portion is provided near the connecting portion between the flexible region 32 and the semiconductor substrate 33 or near the connecting portion between the flexible region 32 and the movable element 35 to reduce the stress applied when the flexible region 32 is displaced. The effect of this is the same as that described with reference to FIGS. 21 and 22.

(Embodiment 11) Next, an eleventh embodiment of the present invention will be described. FIG. 32 is a partially broken perspective view showing the structure of the semiconductor microrelay in the present embodiment. The semiconductor microrelay shown in FIG. 32 is composed of a fixed piece 65 which is a fixed element having fixed contacts 67 and 68 provided on the surface thereof, and an actuator portion joined to the upper portion thereof by anodic bonding, eutectic bonding or the like. ,
This actuator section is constituted by the semiconductor microactuator 41 shown in FIG.

A movable contact 66 is provided on the lower surface of the movable element 45 of the semiconductor microactuator 41. The fixed contacts 67 and 68 on the fixed piece 65 are
6 is provided at a position corresponding to the movable contact 66 so as to be able to contact the movable contact 66.

Here, when a current flows through the diffusion resistor 46 and the flexible region 42 is heated, the flexible region 42 is displaced due to a difference in thermal expansion between the thin portion 42S and the thin film 42M, and the movable element 4
5 is displaced. Due to this displacement, the movable contact 66 provided on the lower surface of the movable element 45 comes into contact with the fixed contacts 67 and 68, and the fixed contacts 67 and 68 conduct through the movable contact 66 to turn on the relay.

The actuator section of the semiconductor microrelay of this embodiment is constituted by a semiconductor microactuator 41, and as described in the sixth embodiment, the flexible region 4
2 and the semiconductor substrate 43 have a high thermal insulation effect, and a semiconductor microrelay with low power consumption can be obtained. Further, the semiconductor microactuator 41 has a cantilever structure having the semiconductor substrate 43 as a fixed end, so that a semiconductor microrelay having a large contact pressure can be obtained.

(Twelfth Embodiment) Next, a twelfth embodiment will be described. FIG. 33 is a perspective view showing the structure of the semiconductor microrelay in the present embodiment, in which the actuator section shown in FIG. 32 is constituted by the semiconductor microactuator 41b shown in FIG.

That is, in the semiconductor microrelay of this embodiment, the thin film 47M of the flexible region 42 and the heat insulating region 47 connecting the flexible region 42 and the semiconductor substrate 43 are made of the same material such as polyimide. .

The semiconductor micro-relay shown in FIG. 33 has a concave portion 45H in the movable element 45, has a smaller heat capacity than the non-recessed portion (see FIG. 37), and has a flexible region 42. FIG. 2 shows that the temperature of the movable element can be rapidly increased and that the weight (volume) of the movable element is small, so that it does not malfunction due to an external impact.
5 as described above.

Next, a method of manufacturing the semiconductor micro relay of the present embodiment will be described. For example, a semiconductor substrate 43 such as a silicon substrate (see FIG. 34A) is etched away from the lower surface with KOH or the like using a silicon nitride film or the like as a mask to form a gap 40 (see FIG. 34B). The gap 40 is a contact gap between the movable contact and the fixed contact in the semiconductor micro relay. Here, the semiconductor substrate 43, which is a silicon substrate, may be either p-type or n-type, and the crystal orientation is preferably <100>.

Next, a diffusion resistor 46 is formed on the upper surface of the semiconductor substrate 43 by ion implantation or impurity diffusion (see FIG. 34C). Here, the impurity may be either p-type or n-type.

Further, a silicon nitride film or the like is formed on both surfaces of the semiconductor substrate 43 and patterned. Thereafter, the upper surface of the semiconductor substrate 43 is removed by etching with KOH or the like (anisotropic etching), and a concave portion 45H is formed on the upper part of the movable element 45 to form a hollow shape. A recess is provided by anisotropic etching), and the bottom is formed as a thin portion 42S constituting a flexible region (FIG. 34).
(D)).

Next, holes 47B, 47C are formed on the upper surface of the semiconductor substrate 43 by etching using a silicon nitride film or the like as a mask, and forming portions to become the heat insulating regions 47, 47a.
Is formed (see FIG. 35A). The depth etched at this time corresponds to the thickness of the heat insulating regions 47 and 47a.

Then, in the next step, an aluminum thin film is formed by sputtering or the like and is patterned to form a wiring 49A for supplying power to the diffusion resistor 46 and the like (see FIG. 35B).

Next, a heat insulating material such as polyimide is coated on the entire surface of the semiconductor substrate 43 to fill the holes 47B and 47C. Thereafter, the heat insulating material other than the heat insulating material above the embedded portion and the thin portion 42S is removed by etching or the like, and the heat insulating regions 47 and 47a and the thin film 47M are formed of the same material such as polyimide (FIG. 35). (C)
reference). Then, the lower surfaces of the heat insulating regions 47 and 47a are removed by etching (see FIG. 35D), and the below-described movable contact 66 made of gold cobalt or the like is formed on the lower surface of the movable element 45 by plating or the like (FIG. 35). (E)).

Thereafter, the semiconductor substrate 43 thus processed is fixed to a fixed contact 6 made of gold cobalt or the like by plating or the like.
The fixed piece 65 on which is formed 7 is bonded by anodic bonding or the like (FIG. 36A). Finally, the movable element 45 and the flexible region 42 are formed by RIE or the like into a semiconductor substrate 43 serving as a frame.
And a semiconductor microrelay is manufactured (FIG. 36B). That is, the semiconductor microactuator 41b is manufactured.

As described above, since the thin film 47M of the flexible region 42 and the heat insulating region 47 are simultaneously formed of the same material, the manufacturing process can be simplified and the cost can be reduced.

Here, the so-called bimetal structure composed of the thin portion 42S of the flexible region 42 and the thin film 47M in the semiconductor microrelay of the present embodiment is shown in FIG. As shown, a thin portion 42 made of silicon having a thickness of 10 μm is formed.
On top of S, a 20 μm thick polyimide (trade name: Photo Nice) is formed as a thin film 47M. The plane size of the flexible region 42 is 1000 μm × 1000 μm. At this time, the bending of the flexible region 42 is expressed by the following Timochenko equation.

[0206]

(Equation 16)

Here, ΔT indicates a temperature change.

FIG. 39 shows the result of calculation by introducing specific numerical values into the above equation. As shown in FIG.
The higher the temperature of the device, the greater the displacement (bending). When this bend becomes larger than the contact gap between the movable contact 66 and the fixed contacts 67 and 68 of the semiconductor microrelay, the movable contact 66 and the fixed contacts 67 and 68 come into contact and the relay is turned on.

Here, the contact gap is 20 μm,
Consider the operation of the bimetal when the bimetal is set at 200 ° C. As shown in FIG. 39, the displacement of the bimetal at 200 ° C. is about 65 μm.

The semiconductor micro relay has a cantilever structure, and the beam corresponding to the flexible region 42 is displaced as shown in FIG. The displacement Xa of the tip is Xa = (Fa · τa
³ ) / (3Ea · Ia). Fa is the force applied to the tip of the beam, ta is the thickness of the beam, τa is the length of the beam, E
a shows the Young's modulus of the beam. Here, Ia denotes the second moment of the beam, if its cross section is ^{rectangular, Ia = ba · ta 3/} 12 (ba is the depth width of the beam) for expressed by deflection of the tip Xa Is Xa = 4 · F
a · τa ³ / a ^{(ba · ta 3 · Ea)} . From this equation, the force Fa applied to the tip of the beam is Fa = (Xa · ba
· Ta ³ · Ea) / (4 · τa ³ ). here,
Assuming that the contact gap is 20 μm, the contact pressure fa becomes fa =
((Xa-20 μm) · ba · ta ³ · Ea) / (4 ·
τa ³ ). The deflection Xa at the tip is Xa = 65 μm
Therefore, the contact pressure fa is: fa = 0.87 gf = 8.5
× 10 ⁻³ N, and a contact pressure close to 1 gf (9.8 × 10 ⁻³ N) can be obtained.

(Embodiment 13) Next, a thirteenth embodiment of the present invention will be described. FIG. 41 is a perspective view showing the structure of the semiconductor micro relay of the present embodiment. The semiconductor microrelay shown in FIG. 41 is obtained by configuring the actuator section of the semiconductor microrelay shown in FIG. 33 with the semiconductor microactuator 41 shown in FIG.
The difference is that the thin film 42M of the flexible region 42 is formed of a metal thin film such as an aluminum thin film or a nickel thin film.

In the semiconductor micro relay of the present embodiment, the concave portion 45H is formed in the movable element 45, as compared with the case where no concave portion is formed as in the semiconductor micro relay shown in FIG. This embodiment is similar to the twelfth embodiment in that the temperature of the movable element can be rapidly increased and the weight (volume) of the movable element can be reduced, so that a malfunction can be prevented by an external impact.

Next, a method of manufacturing the semiconductor microrelay shown in FIG. 41 will be described. First, a manufacturing method when the thin film 42M forming the flexible region 42 is formed of an aluminum thin film will be described.

For example, a semiconductor substrate 43 such as a silicon substrate
The gap 40 is formed by etching the lower surface (see FIG. 42A) from the lower surface using KOH or the like with a silicon nitride film or the like as a mask (see FIG. 42B). The gap 40 is a contact gap between the movable contact and the fixed contact in the semiconductor micro relay. Here, the semiconductor substrate 43 (silicon substrate) may be either p-type or n-type,
Desirable crystal orientation is <100>.

Next, a diffusion resistor 46 is formed on the upper surface of the semiconductor substrate 43 by ion implantation or impurity diffusion (see FIG. 42C). Here, the impurity may be either p-type or n-type.

Further, a silicon nitride film or the like is formed on both surfaces of the semiconductor substrate 43 and patterned. Thereafter, the upper surface of the semiconductor substrate 43 is removed by etching with KOH or the like (anisotropic etching), and a concave portion 45H is formed on the upper part of the movable element 45 to form a hollow shape. Anisotropic etching) is removed to form a concave portion, and the bottom surface is formed as a thin portion 42S constituting a flexible region (FIG. 42).
(D)).

Next, holes 47B and 47C are formed on the upper surface of the semiconductor substrate 43 by etching using a silicon nitride film or the like as a mask and forming portions to become heat insulating regions 47 and 47a.
Is formed (see FIG. 43A). The depth etched at this time corresponds to the thickness of the heat insulating regions 47 and 47a.

In the next step, as shown in FIG. 43B, an aluminum thin film is formed by sputtering or the like and patterned to form a thin film 42 constituting a flexible region.
M and a wiring 49A for supplying power to the diffusion resistor 46 are formed. Then, a heat insulating material such as polyimide is coated on the entire surface of the semiconductor substrate 43, the holes 47B and 47C provided on the upper surface of the semiconductor substrate 43 are filled, and the heat insulating material other than the embedded portions is removed by etching or the like. The heat insulating regions 47 and 47a are formed (see FIG. 43 (c)).

Thereafter, the lower surfaces of the heat insulating regions 47 and 47a are removed by etching to form the heat insulating regions 47 and 47a composed of only a heat insulating material (see FIG. 43 (d)).
Next, a movable contact 66 made of gold cobalt or the like is formed on the lower surface side of the movable element 45 by plating or the like.

Next, the semiconductor substrate 4 thus processed
3 and a fixed piece 65 on which a fixed contact 67 made of gold cobalt or the like is formed by plating or the like (see FIG. 44A), and finally, the movable element 45 and the flexible region 42 are framed by RIE or the like. Body semiconductor substrate 43
And a semiconductor micro relay is manufactured. That is, the semiconductor microactuator 41a is manufactured (see FIG. 44B).

Next, a description will be given of a manufacturing method when the thin film 42M of the semiconductor microrelay shown in FIG. 41 is made of nickel. As shown in the steps of FIGS. 45A to 45E, a step of forming a gap 40 on the lower surface of the semiconductor substrate 43, a step of forming a diffusion resistor 46 on the upper surface of the semiconductor substrate 43, The steps of forming the concave portion 45H, forming the thin portion 42S of the flexible region 42, and forming the holes 47B and 47C, which are portions to be the thermal expansion regions later, are shown in FIGS. This is the same as the process described with reference to FIG.

In the next step, as shown in FIG. 46A, an aluminum thin film is formed by sputtering or the like and patterned to form a wiring 49A for supplying power to the diffusion resistor 46 and the like. Next, FIG.
As shown in (b), a heat insulating material such as polyimide is coated on the entire surface of the semiconductor substrate 43, and the holes 47B and 47C provided on the upper surface of the semiconductor substrate 43 are filled. The heat insulating regions 47 and 47a are formed by removal by etching or the like.

Thereafter, the lower surfaces of the heat insulating regions 47 and 47a are removed by etching (see FIG. 46 (c)).
A nickel thin film is formed on the upper surface of S as a thin film 42M by plating or the like (see FIG. 46 (d)), and the movable element 4
A movable contact 66 made of gold-cobalt or the like is formed on the lower surface side of 5 by plating or the like (see FIG. 46E).

Next, the semiconductor substrate 43 thus processed is fixed to the fixed piece 65 on which the fixed contact 67 made of gold cobalt or the like is formed by plating or the like (see FIG. 47A). Finally, the movable element 45 and the flexible region 42 are separated from the semiconductor substrate 43 serving as a frame by RIE or the like, and a semiconductor microrelay is manufactured (see FIG. 47B). That is, the semiconductor microactuator 41a is manufactured.

Here, the thin portion 42S and the thin film 42M of the flexible region 42 in the semiconductor microvalve shown in FIG.
FIG. 49 shows the structure of a so-called bimetal made of. As shown, a thin portion 4 made of 15 μm thick silicon
On the 2S, an aluminum thin film having a thickness of 5 μm is formed as a thin film 42M. The plane size of the flexible region 42 is 1000 μm × 1000 μm.

At this time, the displacement (bending) of the flexible region 42 is represented by the following Timochenko equation.

[0227]

(Equation 17)

Here, ΔT indicates a temperature change.

FIG. 50 shows the result of calculation by introducing specific numerical values into the above equation. As shown in FIG.
The displacement (bending) increases as the temperature increases. This displacement is caused by the movable contact 66 and the fixed contact 6 of the semiconductor micro relay.
When the contact gap becomes larger than the contact gap of 7, 68, the movable contact 66 and the fixed contacts 67, 68 come into contact, and the relay is turned on.

Here, the contact gap is 20 μm,
The operation when the flexible region 42 is set to 200 ° C. will be considered.
As shown in FIG. 50, the displacement of the flexible region 42 at 200 ° C. is about 70 μm. As described above, the contact pressure fa becomes fa = ((Xa−20 μm).
m) · ba · ta ³ · Ea) / (4 · τa ³ ). Therefore, when the contact pressure fa is obtained, fa = 0.82 gf = 8.
0 × 10 ⁻³ N, almost 1 gf (9.8 × 10 ⁻³ N)
Is obtained.

On the other hand, when a nickel thin film is used as the thin film 42M, the displacement (bending) of the flexible region 42 with respect to a temperature change is small because nickel has a smaller coefficient of thermal expansion than aluminum. However, since nickel has a higher Young's modulus than aluminum, a large thermal stress can be generated.

FIG. 51 shows displacement characteristics of the flexible region 42 when the thin film 42M is made of aluminum and nickel when the thickness of the thin portion 42S made of silicon is changed. I have. Aluminum and nickel are each 5 μm thick, and the temperature of the flexible region 42 is calculated at 200 ° C. As is clear from the figure, when the thickness of the thin portion 42S is 20 μm, the characteristics of aluminum and nickel are reversed, and when the thickness becomes 20 μm or more,
When the thin film 42M is made of nickel, the displacement characteristics of the flexible region 42 are large. Thus, when the thickness of the thin portion 42S is large, better characteristics can be obtained by using nickel as the thin film 42M.

Here, another configuration example of the semiconductor microrelay in this embodiment is shown in FIG. The semiconductor microrelay of FIG. 52 differs from that shown in FIG. 41 in that the fixing piece 65 and the semiconductor microactuator 41a are joined (for example, anodic bonding) via a spacer layer 63 made of polyimide in FIG. This is similar to the embodiment corresponding to FIG. 28 in that the stress generated between both the fixing piece 65 and the semiconductor microactuator 41a can be absorbed and reduced.

[0234]

As described above, according to the first aspect of the present invention, there is provided a semiconductor substrate, a flexible region displaced with respect to the semiconductor substrate due to a change in temperature, and a flexible region provided between the semiconductor substrate and the flexible region. The semiconductor substrate and the flexible region are connected to each other, and the flexible region is constituted by a resin thermal insulating region. By providing the resin thermal insulating region between the semiconductor substrate and the flexible region,
To prevent the escape of heat when changing the temperature of the flexible region,
Power consumption can be reduced, and the manufacturing process is simple.

Further, according to the second aspect of the present invention, in the first aspect of the present invention, the material constituting the heat insulating region has a thermal conductivity of about 0.4 W / (m · ° C.) or less.
The thermal insulation between the flexible region and the semiconductor substrate is improved.

Further, according to the invention of claim 3, in the invention of claim 2, since the material constituting the heat insulating region is polyimide, the heat insulating property between the flexible region and the semiconductor substrate is improved, and the manufacturing cost is improved. Becomes easier.

According to a fourth aspect of the present invention, in the second aspect of the present invention, since the material forming the heat insulating region is a fluorinated resin, the thermal insulation between the flexible region and the semiconductor substrate is improved. , Making it easier to manufacture.

[0238] According to a fifth aspect of the present invention, in the first aspect of the present invention, the reinforcing layer made of a material harder than the material forming the heat insulating region is provided in the heat insulating region. Since it is provided, the connection strength between the semiconductor substrate and the flexible region can be increased.

[0239] According to the invention of claim 6, in the invention of claim 5, the Young's modulus of the reinforcing layer is 9.8 × 10
^{Since it is 9} N / m ² or more, the connection strength between the semiconductor substrate and the flexible region can be increased.

According to a seventh aspect of the present invention, in the sixth aspect, since the reinforcing layer is a silicon dioxide thin film, the connection strength between the semiconductor substrate and the flexible region can be increased.

According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, portions of the semiconductor substrate and the flexible region which are in contact with the heat insulating region have a comb-like shape. Therefore, the connection strength between the semiconductor substrate and the flexible region can be increased.

A ninth aspect of the present invention includes the semiconductor device according to any one of the first to eighth aspects, and a movable element connected to the flexible region, wherein a temperature of the flexible region is increased. Since the movable element is displaced with respect to the semiconductor substrate when is changed, the semiconductor element can be driven with low power consumption and has the same effect as the invention of claim 1 to claim 8. An actuator is obtained.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, the flexible region has a cantilever structure, so that a semiconductor microactuator having a large displacement of the movable element can be obtained.

According to the eleventh aspect, in the ninth aspect, since the movable element is supported by a plurality of flexible regions, the movable element can be stably supported.

According to a twelfth aspect of the present invention, in the invention of the eleventh aspect, since the flexible region has a cross shape with the movable element interposed therebetween, the displacement accuracy of the movable element is improved.

According to a thirteenth aspect of the present invention, in the eleventh aspect, the displacement of the movable element includes a displacement that rotates in a horizontal direction with respect to a substrate surface of the semiconductor substrate. Becomes big.

According to a fourteenth aspect of the present invention, in the eleventh or thirteenth aspect, each of the flexible regions has four L-shaped flexible regions centered on the movable element. Are provided at equal intervals in four directions, so that the length of the flexible region can be increased, and therefore, the displacement of the movable element can be increased.

According to a fifteenth aspect of the present invention, in any one of the ninth to fourteenth aspects, the flexible region comprises at least two regions having different coefficients of thermal expansion, and the difference in the coefficient of thermal expansion is reduced. Since the displacement is made accordingly, the displacement of the flexible region can be obtained by the temperature change of the flexible region.

According to a sixteenth aspect, in the fifteenth aspect, the flexible region has a region made of silicon and a region made of aluminum. Due to the temperature change, displacement of the flexible region due to the difference in thermal expansion between aluminum and silicon can be obtained.

According to a seventeenth aspect, in the fifteenth aspect, the flexible region includes a region made of silicon and a region made of nickel. Due to the temperature change, displacement of the flexible region due to a difference in thermal expansion between nickel and silicon can be obtained.

According to an eighteenth aspect of the present invention, in the fifteenth aspect, at least one of the regions constituting the flexible region is formed of the same material as the heat insulating region. And the heat insulating region can be formed simultaneously, so that the manufacturing process can be simplified and the cost can be reduced.

According to a nineteenth aspect of the present invention, in the invention according to the eighteenth aspect, the flexible region has a region made of silicon, and the polyimide is used as a region made of the same material as the heat insulating region. In addition to the effects similar to those of the eighteenth aspect, the flexible region can be displaced due to a difference in thermal expansion between silicon and polyimide due to a temperature change in the flexible region. The thermal insulation of the flexible region is also improved.

According to a twentieth aspect of the present invention, in the invention according to the eighteenth aspect, the flexible region includes a region made of silicon, and the flexible region is made of fluorine as a region made of the same material as the heat insulating region. In addition to the effects similar to those of the eighteenth aspect, in addition to the effects similar to those of the eighteenth aspect, it is possible to obtain a displacement of the flexible region due to a difference in thermal expansion between silicon and the fluorinated resin due to a temperature change in the flexible region. In addition, the fluorinated resin improves the thermal insulation of the flexible region.

According to a twenty-first aspect of the present invention, in the invention according to any one of the ninth to fourteenth aspects, the flexible region is made of a shape memory alloy, and the flexible region is formed by a temperature change of the flexible region. The displacement of the flexure region can be obtained.

[0255] According to a twenty-second aspect of the present invention, in any one of the ninth to twenty-first aspects, the flexible region and the movable element are connected between the flexible region and the movable element. Since the heat insulating region made of a flexible resin is provided, thermal insulation between the flexible region and the movable element can be ensured, and power consumption when the temperature of the flexible region is changed can be further suppressed.

According to a twenty-third aspect of the present invention, in the twenty-second aspect, the rigidity of the heat insulating region provided between the semiconductor substrate and the flexible region and the rigidity of the flexible region and the movable element are different. In order to make the rigidity of the heat insulating region provided between the heat insulating regions different, the direction of displacement of the movable element can be determined based on the difference in rigidity of each heat insulating region.

According to a twenty-fourth aspect of the present invention, in any one of the ninth to twenty-third aspects, a heating means for heating the flexible region is provided. Temperature can be changed.

According to a twenty-fifth aspect of the present invention, in the invention according to any one of the ninth to twenty-fourth aspects, a wiring for supplying electric power to a heating means for heating the flexible region is provided in the heat insulating region. Since the wirings are not formed, the thermal insulation distance of the wiring can be increased, and the thermal insulation of the flexible region can be improved.

According to a twenty-sixth aspect of the present invention, in the invention according to any one of the ninth to twenty-fifth aspects, since the movable element has a recess, the heat capacity of the movable element is reduced. In addition, the temperature change of the flexible region can be quickened.

According to a twenty-seventh aspect of the present invention, in any one of the ninth to twenty-sixth aspects, a connecting portion between the flexible region and the movable element or a connecting portion between the flexible region and the semiconductor substrate. Since the roundness for relaxing the stress is provided in the vicinity of the portion, the stress applied to the vicinity of the connecting portion when the flexible region is displaced is dispersed by the roundness, so that the portion can be prevented from being broken.

According to a twenty-eighth aspect of the present invention, in the twenty-seventh aspect, the semiconductor substrate is provided with a protruding portion protruding toward a connection portion with the flexible region. Since the shape of the semiconductor substrate on the substrate surface is formed in an R shape at both ends of the base end of the protrusion, the stress applied to both ends of the base of the protrusion when the flexible region is displaced is rounded. By dispersing, the portion can be prevented from being broken.

According to a twenty-ninth aspect of the present invention, in the method of manufacturing a semiconductor microactuator according to the twenty-seventh aspect, the semiconductor substrate is etched from the substrate surface to form a concave portion, and the bottom portion is formed as the flexible region. A sacrificial layer is formed at the boundary between the bottom surface and the side surface of the concave portion, and the sacrificial layer is removed by etching to form an R shape, thereby forming the roundness. It can be used to form a rounded shape, and furthermore, when the flexible region is displaced, the stress applied to the boundary between the bottom surface and the side surface of the concave portion is dispersed by the rounded shape, thereby preventing that portion from being broken. .

According to a thirtieth aspect of the present invention, there is provided the semiconductor microactuator according to any one of the ninth to the twenty-ninth aspects, wherein the semiconductor microactuator is connected to the semiconductor microactuator, and the fluid amount flowing according to the displacement of the movable element is reduced. With a fluid element having a changing flow path,
In addition to being able to be driven with low power consumption, a semiconductor microvalve having the same effects as the inventions of claims 9 to 29 is obtained.

According to a thirty-first aspect of the present invention, in the thirty-third aspect, since the semiconductor microactuator and the fluid element are joined by anodic joining, both can be joined.

According to a thirty-second aspect of the present invention, in the thirty-third aspect, the semiconductor microactuator and the fluid element are joined by eutectic joining, so that both can be joined.

According to a thirty-third aspect of the present invention, in the thirty-third aspect, the semiconductor microactuator and the fluid element are joined via a spacer layer, so that the semiconductor microactuator and the fluid element are joined. The difference in thermal expansion between the two can be absorbed by the spacer layer, and the stress applied to the flexible region can be suppressed.

According to a thirty-fourth aspect, in the thirty-third aspect, since the spacer layer is made of polyimide, a difference in thermal expansion between the semiconductor microactuator and the fluid element can be reduced by the elasticity of the polyimide when the semiconductor microactuator and the fluid element are joined. The stress applied to the flexible region can be suppressed by absorption.

According to a thirty-fifth aspect of the present invention, there is provided the semiconductor micro-actuator according to any one of the ninth to twenty-ninth aspects, wherein the movable element is provided with a movable contact,
Since a fixed element which has a fixed contact capable of contacting the movable contact at the corresponding position and which is joined to the semiconductor microactuator is provided, in addition to being drivable with low power consumption, claim 9 to claim 9 A semiconductor microrelay having the same effects as the invention of Item 29 is obtained.

According to a thirty-sixth aspect of the present invention, in the thirty-fifth aspect of the present invention, the fixed contacts are spaced apart from each other by being in contact with the movable contact and conducting with each other via the movable contact. A semiconductor micro relay capable of conducting a fixed contact can be obtained.

According to a thirty-seventh aspect, in the thirty-fifth or thirty-sixth aspect, since the movable contact and the fixed contact are made of gold cobalt, conduction between the movable contact and the fixed contact is possible.

According to a thirty-eighth aspect of the present invention, in the invention according to any one of the thirty-fifth to thirty-seventh aspects, the semiconductor microactuator and the fixing element are joined by anodic joining. It becomes possible.

According to a thirty-ninth aspect of the present invention, in the semiconductor device according to any one of the thirty-fifth to thirty-seventh aspects, the semiconductor microactuator and the fixing element are joined by eutectic joining. Becomes possible.

According to a forty-ninth aspect of the present invention, in the semiconductor device according to any one of the thirty-fifth to thirty-seventh aspects, the semiconductor micro-actuator and the fixing element are joined via a spacer layer. The difference in thermal expansion between the actuator and the fluid element when they are joined can be absorbed by the spacer layer, and the stress applied to the flexible region can be suppressed.

According to a forty-first aspect of the present invention, in the forty-ninth aspect, since the spacer layer is made of polyimide, a difference in thermal expansion between the semiconductor microactuator and the fluid element when the semiconductor microactuator and the fluid element are joined can be reduced by the elasticity of the polyimide. The stress applied to the flexible region can be suppressed by absorption.

According to a twenty-second aspect of the present invention, in the method of manufacturing a semiconductor microactuator according to the eighteenth aspect, one surface of the semiconductor substrate is removed by etching to make the bottom surface one of the flexible regions constituting the flexible region. A step of forming the concave portion of the movable element by etching and removing the other surface of the semiconductor substrate at the same time as forming the region, and removing the other surface of the semiconductor substrate by etching to form at least the semiconductor substrate and the flexible substrate. Forming a portion to be the heat insulating region provided between the bending regions; and embedding a heat insulating material in the portion to be the heat insulating region to form the heat insulating region and simultaneously applying the heat insulating material to the semiconductor substrate. 1 to form the flexible region by applying to the other surface of
Since there is a step of forming one region, by simultaneously forming the heat insulating region and one region constituting the flexible region with the same material, the manufacturing process can be simplified and the cost can be reduced.

According to a forty-third aspect of the present invention, in the method of manufacturing a semiconductor micro-actuator according to the sixteenth aspect, one surface of the semiconductor substrate is removed by etching to form a bottom surface of one of the flexible regions. A step of forming the concave portion of the movable element by etching and removing the other surface of the semiconductor substrate at the same time as forming the region, and removing the other surface of the semiconductor substrate by etching to form at least the semiconductor substrate and the flexible substrate. Forming a portion to be the heat insulating region provided between the flexible regions, forming an aluminum thin film on the other surface of the semiconductor substrate, a region formed of aluminum in the flexible region, Forming a wiring for supplying power to the heating means, and embedding a heat insulating material in a portion to be the heat insulating region to form the heat insulating region Because having a degree, and the region formed by the aluminum of the flexible region, by simultaneously forming the wiring for supplying power to the heating means, it is possible to reduce the cost and simplify the manufacturing process.

According to a forty-fourth aspect of the present invention, in the method for manufacturing a semiconductor microactuator according to the seventeenth aspect, one surface of the semiconductor substrate is removed by etching to form a bottom surface of one of the flexible regions. A step of forming the concave portion of the movable element by etching and removing the other surface of the semiconductor substrate at the same time as forming the region, and removing the other surface of the semiconductor substrate by etching to remove at least the semiconductor substrate Forming a portion serving as the heat insulating region provided between the bending regions; forming a wiring for supplying power to the heating means; and embedding a heat insulating material in the portion serving as the heat insulating region. Forming a heat insulating region, and forming a nickel thin film on the other surface of the semiconductor substrate as a region composed of nickel of the flexible region. Since a step of, it can provide a region composed of nickel flexible area.

According to a forty-fifth aspect of the present invention, in the method for manufacturing a semiconductor device according to the first aspect, at least one surface of the semiconductor substrate is removed by etching to be provided at least between the semiconductor substrate and the flexible region. Forming a portion to be the heat insulating region, embedding a heat insulating material in the portion to be the heat insulating region, and forming the heat insulating region by etching away the other surface of the semiconductor substrate. Accordingly, a heat insulating region can be formed between the semiconductor substrate and the flexible region.

According to a forty-sixth aspect, in the method of manufacturing a semiconductor device according to the fifth aspect, at least one surface of the semiconductor substrate is removed by etching to be provided at least between the semiconductor substrate and the flexible region. Forming a portion to be the heat insulating region, forming a layer to be a reinforcing layer in the heat insulating region, embedding a heat insulating material in the portion to be the heat insulating region, and the other of a semiconductor substrate The step of forming the heat insulating region by etching away the surface can form a heat insulating region between the semiconductor substrate and the flexible region, and can form a reinforcing layer in the heat insulating region.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view showing a structure of a semiconductor microactuator using a semiconductor device according to a first embodiment of the present invention.

FIGS. 2A and 2B are diagrams showing a structure of the above, wherein FIG. 2A is a cross-sectional view and FIG.

FIG. 3 is a sectional view showing a structure of the semiconductor device according to the first embodiment;

FIG. 4 shows a structural model used for determining the strength of the semiconductor device, in which (a) is a schematic diagram,
(B) is a distribution diagram, and (c) is a distribution diagram.

FIGS. 5A to 5D are cross-sectional views illustrating a manufacturing process of the above semiconductor device.

6A and 6B are diagrams showing a structure of another semiconductor device of the above, wherein FIG. 6A is a sectional view and FIG. 6B is a top view.

FIG. 7 is a sectional view showing the structure of the above.

FIGS. 8A to 8E are cross-sectional views illustrating a manufacturing process according to the embodiment; FIGS.

9A and 9B show a structure of still another semiconductor device of the above, wherein FIG. 9A is a cross-sectional view and FIG. 9B is a top view.

FIG. 10 is a sectional view showing the structure of the above.

FIG. 11 is a partially broken perspective view showing a structure of a semiconductor microactuator corresponding to Embodiment 2 of the present invention.

12A and 12B are diagrams showing the structure of the above, wherein FIG. 12A is a cross-sectional view and FIG. 12B is a top view.

FIG. 13 is a sectional view showing the structure of another semiconductor microactuator according to the embodiment.

FIGS. 14A to 14E are cross-sectional views showing a manufacturing process of the embodiment.

FIGS. 15A to 15D are views showing the same manufacturing process, and FIGS. 15A to 15D are cross-sectional views.

FIG. 16 is a sectional view showing another wiring structure of the semiconductor microactuator according to the above.

FIG. 17 is a partially broken perspective view showing a structure of a semiconductor microactuator corresponding to Embodiment 3 of the present invention.

FIG. 18 is a top view showing the structure of the above.

FIG. 19 is a partially broken perspective view showing the structure of a semiconductor microactuator corresponding to Embodiment 4 of the present invention.

FIG. 20 is a top view showing the structure of the above.

FIG. 21 is a partially broken perspective view showing a structure of a semiconductor microactuator corresponding to Embodiment 5 of the present invention.

FIG. 22 is a top view showing the structure of the above.

FIG. 23 is a partially broken perspective view showing the structure of a semiconductor microactuator corresponding to Embodiment 6 of the present invention.

FIG. 24 is a partially broken perspective view showing a structure of a semiconductor microactuator corresponding to Embodiment 7 of the present invention.

FIG. 25 is a partially broken perspective view showing a structure of a semiconductor microactuator corresponding to Embodiment 8 of the present invention.

FIG. 26 is a partially broken perspective view showing the structure of another semiconductor microactuator according to the above.

FIG. 27 is a partially broken perspective view showing a structure of a semiconductor microvalve corresponding to Embodiment 9 of the present invention.

FIG. 28 is a partially broken perspective view showing the structure of another semiconductor microvalve according to the third embodiment.

FIG. 29 is a partially broken perspective view showing the structure of still another semiconductor microvalve according to the third embodiment.

FIG. 30 is a partially broken perspective view showing a structure of a semiconductor microvalve corresponding to Embodiment 10 of the present invention.

FIG. 31 is a partially cutaway perspective view showing the structure of another semiconductor microvalve of the above.

FIG. 32 is a partially broken perspective view showing a structure of a semiconductor microrelay corresponding to Embodiment 11 of the present invention.

FIG. 33 is a partially broken perspective view showing a structure of a semiconductor microrelay corresponding to Embodiment 12 of the present invention.

FIG. 34 is a view showing a manufacturing process of the above, and (a) to (d) are cross-sectional views.

FIG. 35 is a view showing a manufacturing process of the above, and (a) to (e) are cross-sectional views.

FIG. 36 is a diagram showing a manufacturing process according to the above, wherein (a)
(B) is a sectional view.

FIG. 37 is a partially broken perspective view showing the structure of another semiconductor micro relay of the above.

FIG. 38 is a perspective view used for describing the operation of the semiconductor microrelay.

FIG. 39 is a relationship diagram used for describing the operation of the semiconductor micro relay.

FIG. 40 is a side view used for describing the operation of the semiconductor microrelay.

FIG. 41 is a partially broken perspective view showing a structure of a semiconductor micro relay according to Embodiment 13 of the present invention;

42 (a) to 42 (d) are cross-sectional views showing the same manufacturing process.

FIG. 43 is a view showing a manufacturing step of the above, and (a) to (e) are cross-sectional views.

FIG. 44 is a diagram showing a manufacturing process according to the above, wherein (a)
(B) is a sectional view.

FIG. 45 is a view showing another manufacturing step of the above,
(A) to (e) are all sectional views.

FIG. 46 is a view showing another manufacturing step of the above,
(A) to (e) are all sectional views.

FIG. 47 is a view showing another manufacturing step of the above,
(A) and (b) are cross-sectional views.

FIG. 48 is a partially broken perspective view showing the structure of another semiconductor micro relay of the above.

FIG. 49 is a perspective view used for describing the operation of the above semiconductor micro relay.

FIG. 50 is a relation diagram used for describing the operation of the semiconductor micro relay of the above.

FIG. 51 is a relationship diagram used for describing the operation of the semiconductor microrelay.

FIG. 52 is a view showing a structure of another semiconductor micro relay of the above.

FIG. 53 is a top view showing the structure of a conventional semiconductor microactuator.

FIG. 54 is a cross-sectional view showing the structure of the above.

FIG. 55 is a cross-sectional view showing a structure of a conventional semiconductor micro relay.

FIG. 56 is a schematic view used for describing the same operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor microactuator 2 Flexible area 2S Thin part 2M thin film 3 Semiconductor substrate 4a Wiring 5 Movable element 6 Diffusion resistance 7 Thermal insulation area 8 Semiconductor device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16K 31/70 F16K 31/70 A H01H 37/14 H01H 37/14 37/52 37/52 (72) Invention Person Hitoshi Yoshida 1048 Kadoma Kadoma, Kadoma City, Osaka Prefecture, Japan (72) Inventor Jun Atsushi Ogiwara 1048 Kadoma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Works, Ltd. (72) Shuichi Nagao, Kazuyoshi Nagao, Osaka Prefecture 1048 Kadoma Matsushita Electric Works Co., Ltd. (72) Inventor Masayu Kamakura 1048 Kadoma, Kazuma, Osaka Pref.Matsushita Electric Works Co., Ltd. (72) Inventor Kimiaki Saito 1048 Kadoma, Kadoma, Osaka Pref. In-house (72) Inventor Kazuhiro Shintoki 1048 Odakadoma, Kadoma-shi, Osaka Matsushita Electric Works, Ltd.

Claims (46)

[Claims] 1. A semiconductor substrate, a flexible region displaced with respect to the semiconductor substrate due to a temperature change, and provided between the semiconductor substrate and the flexible region to connect the semiconductor substrate and the flexible region. A semiconductor device comprising: a resin heat insulating region. 2. The semiconductor device according to claim 1, wherein a material constituting the heat insulating region has a thermal conductivity of about 0.4 W / (m · ° C.) or less. 3. The semiconductor device according to claim 2, wherein the material forming the heat insulating region is polyimide. 4. The semiconductor device according to claim 2, wherein the material forming the heat insulating region is a fluorinated resin. 5. The semiconductor according to claim 1, wherein a reinforcing layer made of a material harder than a material forming the heat insulating region is provided in the heat insulating region. apparatus. 6. The reinforcing layer has a Young's modulus of 9.8 × 10
The semiconductor device according to claim 5, characterized in that at ⁹ N / m ² or more. 7. The semiconductor device according to claim 6, wherein said reinforcing layer is a silicon dioxide thin film. 8. The semiconductor device according to claim 1, wherein portions of the semiconductor substrate and the flexible region that are in contact with the heat insulating region are comb-shaped. . 9. The semiconductor device according to claim 1, further comprising: a movable element connected to the flexible region, wherein a temperature of the flexible region changes.
A semiconductor microactuator, wherein the movable element is displaced with respect to the semiconductor substrate. 10. The semiconductor microactuator according to claim 9, wherein the flexible region has a cantilever structure. 11. The semiconductor microactuator according to claim 9, wherein said movable element is supported by a plurality of flexible regions. 12. The semiconductor microactuator according to claim 11, wherein the flexible region has a cross shape across the movable element. 13. The semiconductor microactuator according to claim 11, wherein the displacement of the movable element includes a displacement that rotates in a horizontal direction with respect to a substrate surface of the semiconductor substrate. 14. The flexible region according to claim 11, wherein four flexible regions each having an L-shape are provided at equal intervals in four directions around the movable element. Or a semiconductor microactuator according to claim 13. 15. The flexible region according to claim 9, wherein the flexible region comprises at least two regions having different coefficients of thermal expansion, and is displaced in accordance with a difference in coefficient of thermal expansion.
5. The semiconductor microactuator according to any one of 4. 16. The semiconductor microactuator according to claim 15, wherein said flexible region includes a region made of silicon and a region made of aluminum. 17. The semiconductor microactuator according to claim 15, wherein the flexible region includes a region made of silicon and a region made of nickel. 18. The semiconductor microactuator according to claim 15, wherein at least one of the regions constituting the flexible region is made of the same material as the heat insulating region. 19. The flexible region includes a region made of silicon, and a region made of polyimide as a region made of the same material as the heat insulating region. Item 19. A semiconductor microactuator according to Item 18. 20. The flexible region includes a region made of silicon, and a region made of a fluorinated resin as a region made of the same material as the heat insulating region. Claim 18
The semiconductor microactuator according to claim 1. 21. The semiconductor microactuator according to claim 9, wherein the flexible region is made of a shape memory alloy. 22. A heat insulating region made of a resin connecting the flexible region and the movable element is provided between the flexible region and the movable element. 22. The semiconductor microactuator according to any one of 21. 23. The rigidity of a heat insulating region provided between the semiconductor substrate and the flexible region is different from the rigidity of a heat insulating region provided between the flexible region and the movable element. 23. The semiconductor microactuator according to claim 22, wherein: 24. The semiconductor microactuator according to claim 9, further comprising heating means for heating the flexible region. 25. The wiring according to claim 9, wherein wiring for supplying electric power to a heating means for heating the flexible region is formed without passing through the heat insulating region.
The semiconductor microactuator according to any one of the above. 26. The semiconductor microactuator according to claim 9, wherein a recess is formed in the movable element. 27. The semiconductor device according to claim 9, wherein a rounded portion for reducing stress is provided near a connecting portion between the flexible region and the movable element or near a connecting portion between the flexible region and the semiconductor substrate. 27. The semiconductor microactuator according to claim 26. 28. A protruding portion that protrudes toward a connection portion with the flexible region on the semiconductor substrate,
28. The semiconductor microactuator according to claim 27, wherein the roundness is formed at both ends of a base end of the protruding portion so that a shape of the semiconductor substrate on the substrate surface becomes an R shape. 29. The method of manufacturing a semiconductor microactuator according to claim 27, wherein the semiconductor substrate is etched from the substrate surface to form a concave portion, and a bottom portion thereof is formed as the flexible region. A method of manufacturing a semiconductor microactuator, comprising: forming a sacrificial layer at a boundary of a side surface portion; removing the sacrificial layer by etching to form an R shape; 30. A fluid having a semiconductor microactuator according to claim 9 and a flow path joined to the semiconductor microactuator and having a fluid amount that changes according to displacement of the movable element. A semiconductor microvalve comprising an element. 31. The semiconductor microvalve according to claim 30, wherein the semiconductor microactuator and the fluid element are joined by anodic joining. 32. The semiconductor microvalve according to claim 30, wherein the semiconductor microactuator and the fluid element are joined by eutectic joining. 33. The semiconductor microvalve according to claim 30, wherein the semiconductor microactuator and the fluid element are joined via a spacer layer. 34. The semiconductor microvalve according to claim 33, wherein said spacer layer is made of polyimide. 35. The semiconductor microactuator according to claim 9, wherein a movable contact is provided on the movable element, and a fixed contact that can contact the movable contact is provided at a position corresponding to the movable contact. A semiconductor micro-relay, comprising: a fixing element joined to the semiconductor micro-actuator. 36. The semiconductor microrelay according to claim 35, wherein the fixed contact is a separated contact that comes into contact with the movable contact through the movable contact to make contact with each other. 37. The movable contact and the fixed contact are made of gold-cobalt.
Semiconductor microrelay as described. 38. The semiconductor microrelay according to claim 35, wherein the semiconductor microactuator and the fixed element are joined by anodic bonding. 39. The semiconductor microrelay according to claim 35, wherein the semiconductor microactuator and the fixed element are joined by eutectic joining. 40. The semiconductor microrelay according to claim 35, wherein said semiconductor microactuator and said fixed element are joined via a spacer layer. 41. The semiconductor micro relay according to claim 40, wherein the spacer layer is made of polyimide. 42. The method of manufacturing a semiconductor microactuator according to claim 18, wherein one surface of the semiconductor substrate is removed by etching to form a bottom surface as one region constituting the flexible region, and Etching the other surface of the semiconductor substrate to form a concave portion of the movable element; and etching and removing the other surface of the semiconductor substrate so as to be provided at least between the semiconductor substrate and the flexible region. Forming a portion to be the heat insulating region, and embedding a heat insulating material in the portion to be the heat insulating region, and simultaneously applying the heat insulating material to the other surface of the semiconductor substrate. Forming a single region constituting the flexible region. 43. The method of manufacturing a semiconductor microactuator according to claim 16, wherein one surface of the semiconductor substrate is removed by etching to form a bottom portion as one region constituting the flexible region. Etching the other surface of the semiconductor substrate to form a concave portion of the movable element; and etching and removing the other surface of the semiconductor substrate so as to be provided at least between the semiconductor substrate and the flexible region. Forming a portion to be the heat insulating region, forming an aluminum thin film on the other surface of the semiconductor substrate, and supplying power to the heating unit with the flexible region formed of aluminum. Forming a wiring, and embedding a heat insulating material in a portion to be the heat insulating region to form the heat insulating region. Of manufacturing a semiconductor microactuator. 44. The method of manufacturing a semiconductor microactuator according to claim 17, wherein one surface of the semiconductor substrate is removed by etching to form a bottom surface as one region constituting the flexible region. Etching the other surface of the semiconductor substrate to form a concave portion of the movable element; and etching and removing the other surface of the semiconductor substrate so as to be provided at least between the semiconductor substrate and the flexible region. Forming a portion serving as the heat insulating region, forming a wiring for supplying power to the heating means, and embedding a heat insulating material in the portion serving as the heat insulating region to form the heat insulating region. When,
Forming a nickel thin film on the other surface of the semiconductor substrate as a region composed of nickel of the flexible region. 45. A step of etching and removing one surface of a semiconductor substrate to form at least a portion serving as the heat insulating region provided between the semiconductor substrate and the flexible region; 2. The method of manufacturing a semiconductor device according to claim 1, further comprising the steps of: embedding in a portion to be a heat insulating region; and etching and removing the other surface of the semiconductor substrate to form the heat insulating region. 46. A step of etching and removing one surface of a semiconductor substrate to form at least a portion serving as the heat insulating region provided between the semiconductor substrate and the flexible region; Forming a layer serving as a reinforcing layer, embedding a heat insulating material in a portion serving as the heat insulating region, and forming the heat insulating region by etching away the other surface of the semiconductor substrate. A method for manufacturing a semiconductor device according to claim 5, wherein: