JP3356031B2 - Semiconductor pressure measuring device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an inexpensive and accurate
The present invention relates to a semiconductor pressure measuring device having good sensitivity and overpressure characteristics, a stable manufacturing process, and little variation in characteristics, and a method for manufacturing the same.

[0002]

2. Description of the Related Art FIG. 5 is an explanatory view of a main part of a conventional example, which is disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 9-113390, entitled "Semiconductor Pressure Measuring Apparatus and Manufacturing Method Thereof". FIG. 6 is an explanatory view of the manufacturing process of FIG.

In FIG. 5, a first single crystal silicon substrate 1 is a silicon substrate made of a single crystal. The polysilicon layer 2 is formed on one surface of the first single crystal silicon substrate 1 by a semiconductor conductor process.

[0004] The void chamber 3 is provided in the polysilicon layer 2. The second single-crystal silicon substrate 4 is provided so that one surface thereof is in contact with the other surface of the polysilicon layer 2, and forms the diaphragm 5 together with the portion of the polysilicon layer 2 where the void space 3 is provided.

[0005] The strain detecting element 6 is provided on the other surface side of the second single crystal silicon substrate 4. In this case, a piezoresistive strain gauge or a vibrating strain gauge with fixed beams at both ends is used.

[0006] The pressure guiding hole 7 is formed in the first single crystal silicon substrate 1.
The other surface communicates with the cavity 3 and communicates the cavity 3 with the outside.

[0007] Such an apparatus is manufactured as follows, as shown in FIG. (1) As shown in FIG. 6A, a portion of one surface of the first single crystal silicon substrate 101 is removed by photolithography except for a required portion of the silicon oxide thin film 102.

(2) As shown in FIG. 6B, a polysilicon layer 103, one surface of which is in contact with one surface of a first single crystal silicon substrate 101, is formed by a semiconductor process. (3) As shown in FIG. 6C, the surface of the polysilicon layer 103 is flattened and polished to a predetermined thickness t.

(4) As shown in FIG. 6D, a second single crystal silicon substrate 104 is formed on the other surface of the polysilicon layer 103.
One side is joined. (5) As shown in FIG. 6E, the second single-crystal silicon substrate 104 is formed so as to form a predetermined diaphragm thickness u.
Polish the other side.

(6) As shown in FIG. 6F, a strain detection sensor 105 is provided on the other surface of the second single-crystal silicon substrate 104.
To form (7) As shown in FIG. 6 (g), a pressure guiding hole is formed from the other surface of the first single crystal silicon substrate 101 to reach the silicon oxide thin film 102.

(8) As shown in FIG.
6, the silicon oxide thin film 10 is selectively etched.
Remove 2.

Here, if the first single-crystal silicon substrate 1 and the second single-crystal silicon substrate 5 are joined in a vacuum, the void space 3 becomes a vacuum and becomes an absolute pressure sensor. Also, as shown in FIG. 5, if the pressure guiding hole 7 reaching the gap chamber 3 is formed by etching or the like so that pressure can be introduced into the gap chamber 3, it is possible to measure the gauge pressure and the differential pressure. Become.

[0013]

However, such a semiconductor pressure measuring device has the following problems. In order to directly join silicon, the surface of the polysilicon layer 103 needs to be flat and small in surface roughness after the step of FIG.

However, at the time of the step of FIG.
A step is formed by the thickness of the oxide film 102 formed in the step (a). In order to remove this step, the thickness of the polysilicon layer 103 must be increased to increase the amount of grinding and polishing.

Further, since the thickness of the silicon oxide film 102 constitutes the gap of the void space 3, a high yield can be obtained so that even if fine foreign matter enters and adheres to the void space 3, it can be used. It is desirable that it be as thick as possible. By increasing the thickness of the silicon oxide film 102, the thickness of the polysilicon layer 103 must be increased.

However, when the thickness of the polysilicon layer 103 is increased, the film formation time is prolonged and productivity is deteriorated. When the growth temperature is increased to shorten the film formation time, the grain size of the polysilicon layer 103 increases.

As a result, the step of FIG. 6C, which is a polishing step for reducing the surface roughness, becomes difficult. Also, when the polysilicon layer 103 is thick, the dimensional control becomes difficult because the absolute value of the variation between batches or within the wafer surface increases.

For example, if the thickness of the silicon oxide film 102 is 1
In the case of μm, the polysilicon layer 103 needs to be about 15 μm. Further, in the grinding / polishing step of the step (c) in FIG. 6, there is a variation within the precision of the processing machine. Therefore, when the polishing amount increases, the polysilicon layer 1 in the step (C) of FIG.
03 greatly increases.

As a result, a defect that the polysilicon layer 103 disappears and a defect that the polysilicon layer 103 becomes too thick easily occur.

On the other hand, in order to increase the sensitivity of the device, the polysilicon layer 10 (to make the diaphragm thinner) is used.
It is desirable to make 3 as thin as possible. However, since the polysilicon layer 103 has residual stress, when the thickness of the diaphragm 5 is reduced, the diaphragm 5 is bent under the influence of the residual stress.

FIG. 5 In order to realize the shape of the conventional example, the polysilicon layer of the diaphragm 5 needs to have a thickness of about 3 μm or more. For this reason, there is a limit in reducing the thickness of the diaphragm 5.

The present invention solves these problems. SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor pressure measuring device which is inexpensive, has good accuracy, sensitivity, and overpressure characteristics, has a stable manufacturing process, and has little variation in characteristics, and a method of manufacturing the same.

[0023]

In order to achieve this object, the present invention relates to (1) a semiconductor pressure measuring method in which a void space is provided on one side of a diaphragm and a measuring pressure is applied to the other side of the diaphragm. in the device, a first single crystal silicon substrate, and the first single crystal silicon substrate a polysilicon layer formed by a semiconductor conductor process on one side of the provided in contact is one side to the other surface of the polysilicon layer wherein A second single-crystal silicon substrate forming a diaphragm together with a polysilicon layer, and only one surface side of the first single-crystal silicon substrate is dug.
A concave portion which is lowered to form a void space with one surface of the polysilicon layer; a strain detection sensor provided on the diaphragm; and the void space which is communicated from the other surface of the first single crystal silicon substrate to the void space. And a pressure guiding hole communicating the outside with the outside. (2) In a semiconductor pressure measuring device in which a gap chamber is provided on one surface side of a diaphragm and a measurement pressure is applied to the other surface side of the diaphragm, the first single crystal silicon substrate and the first single crystal silicon substrate a polysilicon layer with one side formed by contact with the semiconductor conductor process on one side, and the second single crystal silicon substrate which is provided with contacts one surface to the other surface of the polysilicon layer, the first single crystal silicon substrate A diaphragm provided on one surface side, forming a diaphragm on the first single crystal silicon substrate to form a cavity with one surface of the polysilicon layer , a strain detection sensor provided on the diaphragm, and the second single crystal A semiconductor pressure measuring device, comprising: a pressure guiding hole which is communicated from the other surface of the silicon substrate to the cavity and communicates the cavity with the outside. (3) A method of manufacturing a semiconductor pressure measuring device in which a gap chamber is provided on one surface side of a diaphragm and a measurement pressure is applied to the other surface side of the diaphragm, comprising the following steps. Production method. (A) forming a first silicon nitride film on a surface of a first single crystal silicon substrate; (B) removing a required portion of the first silicon nitride film on the first single crystal silicon substrate by photolithography; (C) a step of oxidizing the first single crystal silicon substrate to form a first silicon oxide film. (D) removing the first silicon oxide film. (E) forming a second silicon nitride film on the surface of the first single crystal silicon substrate and the surface of the first silicon nitride film where the first silicon oxide film has been removed; (F) removing the second silicon nitride film by anisotropic etching. (G) forming a second silicon oxide film by oxidizing the first single crystal silicon substrate at the location where the second silicon nitride film has been removed; (H) removing the first silicon nitride film and the second silicon nitride film formed on the first single crystal silicon substrate. (I) forming a polysilicon layer on one surface of the first single crystal silicon substrate; (J) a step of flattening the surface of the polysilicon layer by polishing; (K) a step of joining a surface of the first single crystal silicon substrate on which the second silicon oxide film is formed and a second single crystal silicon substrate. (L) a step of polishing the second single-crystal silicon substrate while leaving the thickness of the diaphragm. (M) forming a strain detection sensor on the diaphragm; (N) forming a hole in the first single-crystal silicon substrate to reach the second silicon oxide film; (O) removing the second silicon oxide film by selective etching from a hole reaching the second silicon oxide film. (4) A method of manufacturing a semiconductor pressure measuring device in which a void chamber is provided on one surface side of a diaphragm and a measurement pressure is applied to the other surface side of the diaphragm, comprising the following steps.
Manufacturing method of a semiconductor pressure measuring device. (A) A first silicon nitride film is formed on a surface of a first single crystal silicon substrate.
Forming a recon film; (B) First single-crystal silicon by photolithography
A process for removing a required portion of a first silicon nitride film on a substrate
About. (C) oxidizing the first single-crystal silicon substrate to form a first
Forming a silicon oxide film; (D) removing the first silicon oxide film. (E) Before the place where the first silicon oxide film is removed
The surface of the first single crystal silicon substrate and the first silicon nitride
Forming a second silicon nitride film on the surface of the silicon film
About. (F) This second silicon nitride film is subjected to anisotropic etching.
Therefore, the step of removing. (G) the portion where the second silicon nitride film is removed
Oxidizing a first single crystal silicon substrate to form a second silicon oxide
Forming a film. (H) formed on the first single-crystal silicon substrate
Removing the first silicon nitride film and the second silicon nitride film
Process. (I) A policy is formed on one surface of the first single crystal silicon substrate.
Forming a recon layer; (J) Flatten the surface of this polysilicon layer by polishing
Process. (K) the second oxidation of the first single crystal silicon substrate
Surface on which silicon film is formed and second single crystal silicon
A step of bonding to a substrate. (L) The first single crystal silicon substrate is
Polishing while leaving the thickness. (M) A process for forming a strain detection sensor on this diaphragm
About. (N) performing the second oxidation on the second single-crystal silicon substrate;
Forming a hole reaching the silicon film; (O) Selective etching from the hole reaching the second silicon oxide film
Removing the second silicon oxide film by etching
About.

[0024]

In the above arrangement, one of the high-pressure measurement pressure and the low-pressure measurement pressure is applied to the second single-crystal silicon substrate, and the other of the high-pressure measurement pressure and the low-pressure measurement pressure is applied to the gap chamber. As a result, the diaphragm is distorted according to the pressure difference between the high pressure side and the low pressure side, and the amount of this distortion is electrically detected by the distortion detecting element, and the pressure is measured.

Such an apparatus is manufactured as follows. A first silicon nitride film is formed over a surface of a first single crystal silicon substrate. A required portion of the first silicon nitride film over the first single crystal silicon substrate is removed by photolithography.

The first single crystal silicon substrate is oxidized to
Is formed. The first silicon oxide film is removed. A second silicon nitride film is formed over the surface of the first single crystal silicon substrate where the first silicon oxide film has been removed and the surface of the first silicon nitride film.

This second silicon nitride film is removed by anisotropic etching. The first single crystal silicon substrate where the second silicon nitride film has been removed is oxidized to form a second silicon oxide film. The first silicon nitride film and the second silicon nitride film formed on the first single crystal silicon substrate are removed.

A polysilicon layer is formed on one surface of the first single crystal silicon substrate. The surface of the polysilicon layer is flattened by polishing. The second single crystal silicon substrate
The surface on which the silicon oxide film is formed and the second single crystal silicon substrate are bonded.

The second single crystal silicon substrate is polished except for the thickness of the diaphragm. A distortion detection sensor is formed on the diaphragm. On the first single crystal silicon substrate,
A hole reaching the second silicon oxide film is formed.

The second silicon oxide film is removed from the hole reaching the second silicon oxide film by selective etching. Or, such a device is made as follows:
You. A first silicon nitride film is formed on the surface of the first single crystal silicon substrate.
A cone film is formed. First unit by photolithography
Required part of first silicon nitride film on crystalline silicon substrate
Is removed. Oxidizing the first single crystal silicon substrate to form the first
Is formed. This first silicon oxide
Remove the film. This first silicon oxide film was removed.
A first surface of the first single-crystal silicon substrate and a first nitride
Forming a second silicon nitride film on the surface of the silicon film;
You. This second silicon nitride film is anisotropically etched.
To remove. A piece obtained by removing the second silicon nitride film
Oxidation of the first single crystal silicon substrate at
A silicon film is formed. Form on the first single crystal silicon substrate
The first silicon nitride film and the second silicon nitride formed
The film is removed. One surface of the first single crystal silicon substrate
A silicon layer is formed. The surface of this polysilicon layer
Flatten by polishing. A first single crystal silicon substrate,
A surface on which the second silicon oxide film is formed;
Bonding to a crystalline silicon substrate. First single crystal silicon
The substrate is polished leaving the thickness of the diaphragm. this
A strain detection sensor is formed on the diaphragm. The second simple connection
A hole reaching the second silicon oxide film
Form. Select from holes reaching the second silicon oxide film
The second silicon oxide film is removed by etching.
Hereinafter, a detailed description will be given based on embodiments.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of a main part of an embodiment of the present invention, and FIG. 2 is an explanatory view of a manufacturing process of FIG. In the figure, a polysilicon layer 12 is formed on one surface of a first single crystal silicon substrate 11 by a semiconductor conductor process.

The second single-crystal silicon substrate 13 is provided with one surface in contact with the other surface of the polysilicon layer 12, and forms a diaphragm 14 together with the polysilicon layer 12. The recess 15 has only one surface side of the first single crystal silicon substrate 11.
Drilled down , one surface of the polysilicon layer 12 and the cavity 1
6 is formed.

The strain detecting element 17 is provided on the diaphragm 14. In this case, for example, a piezoresistive strain gauge or a vibrating strain gauge with fixed beams at both ends is used.

The pressure introducing hole 18 is communicated from the other surface of the first single crystal silicon substrate 11 to the cavity 16, and communicates the cavity 16 with the outside.

[0035]

Such an apparatus is manufactured as follows, as shown in FIG. (A) As shown in FIG. 2A, a first silicon nitride film 202 is formed on a surface of a first single crystal silicon substrate 201. (B) As shown in FIG. 2B, a required portion 203 of the first silicon nitride film 202 on the first single crystal silicon substrate 201 is removed by photolithography.

(C) As shown in FIG. 2C, the first single-crystal silicon substrate 201 is oxidized to form a first silicon oxide film 204 at a required position 203. (D) As shown in FIG. 2D, the first silicon oxide film 204 is removed.

(E) As shown in FIG. 2 (e), the surface of the first single crystal silicon substrate 201 at a position 203 where the first silicon oxide film 204 has been removed, and the first silicon nitride film 202 A second silicon nitride film 205 is formed on the surface.

(F) As shown in FIG. 2F, the second silicon nitride film 205 is removed by anisotropic etching. (G) As shown in FIG. 2 (g), the first single crystal silicon substrate 201 where the second silicon nitride film 205 is removed is oxidized to form a second silicon oxide film 206.

(H) As shown in FIG. 2H, the first silicon nitride film 202 and the second silicon nitride film 205 formed on the first single crystal silicon substrate 201 are removed. (I) As shown in FIG. 2 (i), a polysilicon layer 207 is formed on one surface of the first single crystal silicon substrate 201.

(J) As shown in FIG. 2 (j), the surface of the polysilicon layer 207 is flattened by polishing. (K) As shown in FIG. 2K, the surface of the first single crystal silicon substrate 201 on which the second silicon oxide film 206 is formed and the second single crystal silicon substrate 208 are bonded.

(L) As shown in FIG. 2 (l), the second single-crystal silicon substrate 201 is polished except for the thickness of the diaphragm 14. (M) As shown in FIG.
Then, a distortion detection sensor 209 is formed.

(N) As shown in FIG. 2 (n), a second silicon oxide film 206 is formed on a first single crystal silicon substrate 201.
Is formed. (O) As shown in FIG. 2 (o), the second silicon oxide film 2
From the hole 211 reaching 06, the second silicon oxide film 206 is removed by selective etching.

As a result, (1) Since the void chamber 16 is provided in the first silicon single crystal substrate 11, the polysilicon layer 12 forming the diaphragm 14 can be thinned. Specifically, for example, 1 μ
m or less.

As a result, the influence of the residual strain of the polysilicon layer 12 can be reduced, the thickness of the diaphragm 14 can be reduced, and a semiconductor pressure measuring device with improved measurement accuracy and sensitivity characteristics can be obtained. (2) As shown in FIG. 2H, the second silicon oxide film 206 forming the void space 16 is buried in the first silicon single crystal substrate 201.

In such a state, even if the thickness of the second silicon oxide film 206 forming the void space 16 increases, the thickness of the first silicon oxide film 204 and the thickness of the second silicon oxide film 206 increase. Is optimized, the step between the second silicon oxide film 206 and the first silicon single crystal substrate 201 in FIG. 2H is specifically controlled to, for example, a step of 0.1 μm or less. You can do it.

That is, even when the thickness of the second silicon oxide film 206 forming the void space 16 is increased to, for example, 1 μm or more, the step can be controlled to 0.1 μm or less. That is, since the gap of the gap chamber 16 can be enlarged, even if fine foreign matter enters and adheres to the gap chamber 3, it can be used.
High yield can be obtained. Therefore, an inexpensive semiconductor pressure measuring device having stable characteristics can be obtained.

(3) Since the step can be reduced, the polysilicon layer 207 for flattening can be thinned.
For this reason, the polysilicon growth temperature of the polysilicon layer 207 can be lowered, and the gray size can be reduced, so that the polishing process is facilitated. In addition, since the amount of polishing can be reduced, grinding is not required.

Further, since the variation in the thickness of the polysilicon layer 207 within the wafer or between the wafers is reduced, the polishing operation is easy and simple, and an inexpensive semiconductor pressure measuring device can be obtained.

FIG. 3 is an explanatory view of a main part of another embodiment of the present invention, and FIG. 4 is an explanatory view of a manufacturing process of FIG. In the figure,
The polysilicon layer 22 is formed on the first single crystal silicon substrate 21.
Is in contact with one side, and is formed by a semiconductor conductor process.

The second single crystal silicon substrate 23 is provided with one surface in contact with the other surface of the polysilicon layer 22.

The recess 24 is formed in the first single crystal silicon substrate 2
1, a diaphragm 25 is formed on the first single-crystal silicon substrate 21, and a polysilicon layer 22 is formed.
Constituting one side of the air gap chamber 26.

The strain detection sensor 27 is provided on the diaphragm 25. In this case, for example, a piezoresistive strain gauge or a vibrating strain gauge with fixed beams at both ends is used.

The pressure guiding hole 28 is communicated from the other surface of the second single crystal silicon substrate 23 to the cavity 26, and communicates the cavity 26 with the outside.

[0055]

Such an apparatus is manufactured as follows, as shown in FIG. (A) As shown in FIG. 4A, a first silicon nitride film 302 is formed on a surface of a first single crystal silicon substrate 301. (B) As shown in FIG. 4B, a required portion 303 of the first silicon nitride film 302 on the first single crystal silicon substrate 301 is removed by photolithography.

(C) As shown in FIG. 4C, the first single crystal silicon substrate 301 is oxidized to form a first silicon oxide film 304. (D) As shown in FIG. 4D, the first silicon oxide film 304 is removed.

(E) As shown in FIG. 4 (e), the surface of the first single crystal silicon substrate 301 at the place 303 where the first silicon oxide film 304 has been removed and the surface of the first silicon nitride film 302 A second silicon nitride film 305 is formed on the surface.

(F) As shown in FIG. 4F, the second silicon nitride film 305 is removed by anisotropic etching. (G) As shown in FIG. 4 (g), the first single crystal silicon substrate 301 at the portion where the second silicon nitride film 305 has been removed is oxidized to form a second silicon oxide film 306.

(H) As shown in FIG. 4H, the first silicon nitride film 302 and the second silicon nitride film 305 formed on the first single crystal silicon substrate 301 are removed. (I) As shown in FIG. 4 (i), a polysilicon layer 307 is formed on one surface of the first single crystal silicon substrate 301.

(J) As shown in FIG. 4 (j), the surface of the polysilicon layer 307 is flattened by polishing. (K) As shown in FIG. 4K, the surface of the first single-crystal silicon substrate 301 on which the second silicon oxide film 306 is formed and the second single-crystal silicon substrate 308 are joined.

(L) As shown in FIG. 4 (l), the first single-crystal silicon substrate 301 is polished except for the thickness of the diaphragm 25. (M) As shown in FIG. 2 (m), a distortion detection sensor 309 is formed on this diaphragm.

(N) As shown in FIG. 4 (n), a second silicon oxide film 306 is formed on a second single crystal silicon substrate 308.
Is formed. (O) As shown in FIG. 4 (o), the second silicon oxide film 3
From the hole 311 reaching 06, the second silicon oxide film 306 is removed by selective etching.

As a result, diaphragm 25 is formed only of a silicon single crystal material. In other words, a diaphragm having no residual strain can be formed, the diaphragm can be further thinned, and a semiconductor pressure measuring device with further improved measurement accuracy and sensitivity can be obtained.

[0065]

As described above, according to the first aspect of the present invention,
According to the method, since the void chamber is provided in the first silicon single crystal substrate, the polysilicon layer forming the diaphragm can be thinned. Specifically, for example, it can be 1 μm or less.

As a result, the influence of the residual strain of the polysilicon layer can be reduced, the thickness of the diaphragm can be reduced, and a semiconductor pressure measuring device with improved measurement accuracy and sensitivity characteristics can be obtained.

According to the second aspect of the present invention, the diaphragm is formed only of a silicon single crystal material. That is,
A diaphragm having no residual strain can be formed, the diaphragm can be further thinned, and a semiconductor pressure measuring device with further improved measurement accuracy and sensitivity can be obtained.

According to the third and fourth aspects of the present invention, (1) As shown in the step (h), the second silicon oxide film forming the void chamber is embedded in the first silicon single crystal substrate. It will be in a state that was

In such a state, even if the thickness of the second silicon oxide film forming the void space becomes large, the thickness of the first silicon oxide film and the thickness of the second silicon oxide film can be optimized. For example, the step between the second silicon oxide film and the first silicon single crystal substrate in the step (h) is specifically, for example,
It can be controlled to a step of 0.1 μm or less.

That is, even when the thickness of the second silicon oxide film forming the void chamber is increased to, for example, 1 μm or more, the step can be controlled to 0.1 μm or less. That is,
Since the gap in the gap chamber can be enlarged, even if fine foreign matter enters and adheres to the gap chamber, it can be used and a high yield can be obtained. Therefore, an inexpensive semiconductor pressure measuring device having stable characteristics can be obtained.

(2) Since the step can be reduced, the polysilicon layer for flattening can be thinned. For this reason, the polysilicon growth temperature of the polysilicon layer can be lowered, and the gray size can be reduced, so that the polishing process is facilitated. In addition, since the amount of polishing can be reduced, grinding is not required.

Further, since the variation in the thickness of the polysilicon layer within the wafer or between the wafers is reduced, the polishing operation is easy and simple, and an inexpensive semiconductor pressure measuring device can be obtained.

Therefore, according to the present invention, it is possible to realize a semiconductor pressure measuring device and a manufacturing method thereof which are inexpensive, have good accuracy, sensitivity, and overpressure characteristics, have a stable manufacturing process, and have small variations in characteristics. .

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a main part configuration of an embodiment of the present invention.

FIG. 2 is an explanatory view of a manufacturing process of FIG. 1;

FIG. 3 is an explanatory diagram of a main part configuration of another embodiment of the present invention.

FIG. 4 is an explanatory view of a manufacturing process of FIG. 3;

FIG. 5 is an explanatory diagram of a configuration of a conventional example generally used in the related art.

FIG. 6 is an explanatory view of a manufacturing process of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 1st single-crystal silicon substrate 12 polysilicon layer 13 2nd single-crystal silicon substrate 14 diaphragm 15 recess 16 void space 17 strain detecting element 18 pressure-guiding hole 21 first single-crystal silicon substrate 22 polysilicon layer 23 second Single crystal silicon substrate 24 concave portion 25 diaphragm 26 void space 27 strain detection sensor 28 pressure guiding hole 201 first single crystal silicon substrate 202 first silicon nitride film 203 predetermined location 204 first silicon oxide film 205 second nitridation Silicon film 206 Second silicon oxide film 207 Polysilicon layer 208 Second single crystal silicon substrate 209 Strain detection sensor 211 Hole 301 First single crystal silicon substrate 302 First silicon nitride film 303 Predetermined location 304 First oxidation Silicon film 305 Second silicon nitride film 306 Second Silicon film 307 of polysilicon layer 308 second single-crystal silicon substrate 309 strain detection sensor 311 holes

Claims (4)

(57) [Claims] 1. A semiconductor pressure measuring device in which a gap chamber is provided on one surface side of a diaphragm and a measurement pressure is applied to the other surface side of the diaphragm, wherein: a first single crystal silicon substrate; a polysilicon layer formed by a semiconductor conductor process on one surface of the substrate, and the second single crystal silicon substrate constituting the diaphragm together with the polysilicon layer is formed in contact is one side to the other surface of the polysilicon layer, the second Only one side of one single crystal silicon substrate is dug down
And is a recess which forms one surface with a gap chamber of the polysilicon layer, and the strain detection sensor provided in the diaphragm, communicates from the other surface of said first single crystal silicon substrate to the air gap chamber and the gap chamber A semiconductor pressure measuring device, comprising: a pressure guiding hole communicating with the outside. 2. A semiconductor pressure measuring device in which a void chamber is provided on one surface side of a diaphragm and a measurement pressure is applied to the other surface side of the diaphragm, wherein: a first single crystal silicon substrate; a polysilicon layer formed by the semiconductor conductor process against a surface on one side of the substrate, and the second single crystal silicon substrate which is provided in contact with the one surface to the other surface of the polysilicon layer, the first single-crystal silicon A diaphragm provided on one surface side of the substrate, forming a diaphragm on the first single-crystal silicon substrate to form a space on one surface of the polysilicon layer and a void space; a strain detection sensor provided on the diaphragm; A semiconductor pressure measuring device, comprising: a pressure-guiding hole communicating from the other surface of the single-crystal silicon substrate to the cavity and communicating the cavity with the outside. 3. A method of manufacturing a semiconductor pressure measuring device in which a cavity is provided on one surface side of a diaphragm and a measurement pressure is applied to the other surface side of the diaphragm, comprising the following steps: Device manufacturing method. (A) forming a first silicon nitride film on a surface of a first single crystal silicon substrate; (B) removing a required portion of the first silicon nitride film on the first single crystal silicon substrate by photolithography; (C) a step of oxidizing the first single crystal silicon substrate to form a first silicon oxide film. (D) removing the first silicon oxide film. (E) forming a second silicon nitride film on the surface of the first single crystal silicon substrate and the surface of the first silicon nitride film where the first silicon oxide film has been removed; (F) removing the second silicon nitride film by anisotropic etching. (G) forming a second silicon oxide film by oxidizing the first single crystal silicon substrate at the location where the second silicon nitride film has been removed; (H) removing the first silicon nitride film and the second silicon nitride film formed on the first single crystal silicon substrate. (I) forming a polysilicon layer on one surface of the first single crystal silicon substrate; (J) a step of flattening the surface of the polysilicon layer by polishing; (K) a step of joining a surface of the first single crystal silicon substrate on which the second silicon oxide film is formed and a second single crystal silicon substrate. (L) a step of polishing the second single-crystal silicon substrate while leaving the thickness of the diaphragm. (M) forming a strain detection sensor on the diaphragm; (N) forming a hole in the first single-crystal silicon substrate to reach the second silicon oxide film; (O) removing the second silicon oxide film by selective etching from a hole reaching the second silicon oxide film. 4. A method of manufacturing a semiconductor pressure measuring device in which a gap chamber is provided on one surface side of a diaphragm and a measurement pressure is applied to the other surface side of the diaphragm, comprising the following steps: apparatus
Manufacturing method. (A) A first silicon nitride film is formed on a surface of a first single crystal silicon substrate.
Forming a recon film; (B) First single-crystal silicon by photolithography
A process for removing a required portion of a first silicon nitride film on a substrate
About. (C) oxidizing the first single-crystal silicon substrate to form a first
Forming a silicon oxide film; (D) removing the first silicon oxide film. (E) Before the place where the first silicon oxide film is removed
The surface of the first single crystal silicon substrate and the first silicon nitride
Forming a second silicon nitride film on the surface of the silicon film
About. (F) This second silicon nitride film is subjected to anisotropic etching.
Therefore, the step of removing. (G) the portion where the second silicon nitride film is removed
Oxidizing a first single crystal silicon substrate to form a second silicon oxide
Forming a film. (H) formed on the first single-crystal silicon substrate
Removing the first silicon nitride film and the second silicon nitride film
Process. (I) A policy is formed on one surface of the first single crystal silicon substrate.
Forming a recon layer; (J) Flatten the surface of this polysilicon layer by polishing
Process. (K) the second oxidation of the first single crystal silicon substrate
Surface on which silicon film is formed and second single crystal silicon
A step of bonding to a substrate. (L) The first single crystal silicon substrate is
Polishing while leaving the thickness. (M) A process for forming a strain detection sensor on this diaphragm
About. (N) performing the second oxidation on the second single-crystal silicon substrate;
Forming a hole reaching the silicon film; (O) Selective etching from the hole reaching the second silicon oxide film
Removing the second silicon oxide film by etching
About.