JPH11298009A - Manufacture of semiconductor pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the fluctuations of pressure in a reference pressure chamber caused by the effects of moisture, and at the same time, to control the thickness of a diaphragm with high accuracy. SOLUTION: In a method for manufacturing a semiconductor pressure sensor, a sticking process is performed for sticking an SOI substrate 11 carrying a single-crystal silicon layer 9 and a silicon wafer 12 on which a recessed section 13 is formed for a reference pressure chamber to each other. In the sticking process, the substrate 11 and wafer 12 are stuck to each other by closely adhering the surfaces under hydrophilic treatment of the silicon layer 9 on the substrate 11 side and the silicon oxide film 14 on the wafer 12 side to each other after hydrophilic treatment is performed to the surfaces of the layer 9 and film 14, and the process is performed while a relatively low temperature (higher than the actual maximum operating temperature of the sensor) is added in a vacuum state. After the sticking process, an insulating and separating a film 10 is exposed by removing the silicon wafer 8 by performing polishing, chemical etching, etc., by the use of the film 10 as a stopper. Thereafter, diaphragm 5 is formed by exposing the surface of the single-crystal silicon layer 9 by selectively etching off the film 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor pressure sensor of an absolute pressure detection type wherein a pressure applied to a diaphragm is electrically detected based on a stress generated by a pressure difference from a pressure reference chamber. In particular, the present invention relates to a method for manufacturing a semiconductor pressure sensor using a bonding technique.

[0002]

2. Description of the Related Art As a method for manufacturing a semiconductor pressure sensor of this type, there is, for example, a method disclosed in Japanese Patent Application Laid-Open No. 8-236788. In this manufacturing method, first, a first semiconductor substrate in which a concave portion for a diaphragm is formed and a second semiconductor substrate in which an insulating film is formed on the surface are prepared, and these are provided on the concave portion forming surface side and the insulating film surface side. By performing the bonding step, a bonding step of forming a pressure reference chamber formed by hermetically closing the recess is performed. And after this, the first
A step of polishing the semiconductor substrate from a surface opposite to the concave portion forming surface to a predetermined position (actually, a position corresponding to the bottom surface of the second concave portion for the polishing stopper formed in advance to a position deeper than the concave portion) is executed. Thereby, the thickness of the diaphragm is controlled. The pressure reference chamber is generally in a vacuum state (a concept including a reduced pressure state) in order to improve the temperature characteristics of the sensor output.

[0003]

As a technique for bonding semiconductor substrates to each other, a direct bonding method in which the surfaces of both substrates are subjected to a hydrophilic treatment and then bonded to each other is generally used. However, in such a direct bonding method, the surface to be bonded of the substrate is subjected to a hydrophilization treatment, and excess water molecules are present. Therefore, water molecules are present in the pressure reference chamber with the execution of the bonding process. It will be contained. For this reason, when the semiconductor pressure sensor is used in an atmosphere accompanied by a temperature rise, the pressure in the pressure reference chamber fluctuates due to the influence of the water molecules sealed as described above,
There is a problem that the pressure detection sensitivity becomes unstable.

On the other hand, as described above, in the manufacturing method of controlling the thickness of the diaphragm by performing a polishing step of polishing a semiconductor substrate having a concave portion from a surface opposite to the concave portion forming surface, a pressure reference chamber is provided. Due to the fact that is in a vacuum state, bending due to the polishing pressure is likely to occur in the portion where the concave portion for forming the pressure reference chamber exists during polishing. For this reason,
As the diaphragm thickness becomes thinner, the phenomenon that the thickness dimension of the diaphragm part becomes more uneven comes out,
There is a problem that it is very difficult to control the thickness dimension with high accuracy. As a result of the above-described problems, it has been difficult to increase the pressure detection accuracy in a semiconductor pressure sensor manufactured by a conventional method.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent a situation in which the pressure in a pressure reference chamber fluctuates, and to control the thickness of a diaphragm with high accuracy. Accordingly, it is an object of the present invention to provide a method of manufacturing a semiconductor pressure sensor that can improve the accuracy of pressure detection.

[0006]

To achieve the above object, the manufacturing method described in claim 1 can be adopted. According to this manufacturing method, the surface of the first semiconductor substrate on the concave side and the second
As the bonding step of bonding the semiconductor layer side surfaces of the semiconductor substrate to each other is performed in a vacuum atmosphere, the concave portion is sealed, and the pressure reference is reduced accordingly. A chamber is formed. At this time, since the bonding step is performed while applying a temperature higher than the actual maximum use temperature of the semiconductor pressure sensor,
Water molecules attached or absorbed on the inner wall of the pressure reference chamber and the like are expelled, and even when the semiconductor pressure sensor is used in an atmosphere accompanied by a temperature rise,
There is no danger that the pressure in the pressure reference chamber will rise due to the influence of water molecules.

After execution of such a bonding step,
By performing a selective removal step of selectively removing a portion of the second semiconductor substrate other than the semiconductor layer to expose the semiconductor layer, a diaphragm can be formed at a position corresponding to the pressure reference chamber. As a result, a structure is obtained in which the pressure applied to the diaphragm can be electrically detected based on the stress generated by the pressure difference from the pressure reference chamber.

In this case, even when the semiconductor pressure sensor is used in an atmosphere accompanied by a rise in temperature, it is possible to prevent a situation in which the pressure in the pressure reference chamber fluctuates due to the influence of water molecules as described above. Further, the thickness of the diaphragm depends on the thickness of the semiconductor layer provided in advance on the second semiconductor substrate side, and a means for managing the thickness of the diaphragm with high accuracy is provided. Since adoption is possible, it is possible to generally improve the pressure detection accuracy by the diaphragm.

According to the second aspect of the present invention, since the oxide film having a predetermined thickness faces the pressure reference chamber, the excess water molecules can be absorbed by the oxide film. Become. Therefore, even when water molecules remain in the pressure reference chamber, it is possible to suppress a situation in which the pressure in the pressure reference chamber fluctuates due to the influence of the water molecules, thereby contributing to an improvement in pressure detection accuracy. become.

According to a third aspect of the present invention, the bonding step of bonding the surface of the first semiconductor substrate on the concave side and the surface of the second semiconductor substrate on the semiconductor layer side is performed in a vacuum atmosphere. As a result, the concave portion is closed, and a pressure reference chamber in a reduced pressure state is formed accordingly. At this time, since the bonding step is performed after performing the activation processing of irradiating the bonding surface of each of the semiconductor substrates with negative active gas ions, the bonding surface is subjected to the hydrophilic processing. As in the case where the bonding is performed after the bonding, there is no possibility that water molecules remain in the pressure reference chamber, and when the semiconductor pressure sensor is actually used, the pressure in the pressure reference chamber increases due to the influence of the water molecules. Fear is gone.

After performing such a bonding step,
By performing a selective removal step of selectively removing a portion of the second semiconductor substrate other than the semiconductor layer to expose the semiconductor layer, a diaphragm can be formed at a position corresponding to the pressure reference chamber. As a result, a structure is obtained in which the pressure applied to the diaphragm can be electrically detected based on the stress generated by the pressure difference from the pressure reference chamber.

In this case, when the semiconductor pressure sensor is actually used as described above, a situation in which the pressure in the pressure reference chamber fluctuates due to the influence of water molecules can be prevented beforehand, and the thickness of the diaphragm can be reduced. The size depends on the thickness of the semiconductor layer provided in advance on the second semiconductor substrate side, and it becomes possible to employ a means capable of managing the thickness of the diaphragm with high accuracy. Improvement in pressure detection accuracy can be realized.

According to a fourth aspect of the present invention, in the selective removing step, the supporting substrate of the second semiconductor substrate constituted by the SOI substrate is removed by grinding, polishing or etching using the insulating separation film as a stopper. After that, the insulating layer is removed by a selective etching process, so that the semiconductor layer corresponding to the SOI layer is exposed and a diaphragm is formed. In this case, since the thickness of the diaphragm is strictly dependent on the thickness of the semiconductor layer, the thickness of the diaphragm can be managed with high precision.

According to a fifth aspect of the present invention, in the selective removing step, the second semiconductor substrate having the semiconductor layer separated on the front side by a buried oxide film is filled with the buried layer from the back side. After the grinding or polishing using the oxide film as a stopper, the buried oxide film is removed by a selective etching process, so that the semiconductor layer is exposed and a diaphragm is formed. Also in this case, since the thickness of the diaphragm is strictly dependent on the thickness of the semiconductor layer (the position of the buried oxide film), it is possible to control the thickness of the diaphragm with high accuracy. Become.

According to a sixth aspect of the present invention, in the selective removing step, the second semiconductor substrate provided with the impurity diffusion layer reaching the depth corresponding to the thickness of the semiconductor layer from the front surface side, from the back surface side. By performing an etching process using the impurity diffusion layer as a stopper and exposing the impurity diffusion layer as a semiconductor layer, a diaphragm is formed. Also in this case, the thickness of the diaphragm is
Since the thickness is strictly dependent on the thickness of the semiconductor layer (impurity diffusion layer), the thickness of the diaphragm can be managed with high precision.

According to the seventh aspect of the present invention, an ion implantation layer for forming a crystal defect is formed at a predetermined depth from the surface side, and a region located at a position shallower than the ion implantation layer is formed as a semiconductor layer. A second semiconductor substrate is prepared, and in a selective removal step performed after the bonding step, the second semiconductor substrate is separated at a defect layer portion by the ion implantation layer to expose the semiconductor layer in accordance with a heat treatment. As a result, a diaphragm is formed. Also in this case, since the thickness of the diaphragm is strictly dependent on the thickness of the semiconductor layer (the position of the ion-implanted layer), the thickness of the diaphragm can be managed with high precision. .

According to the manufacturing method of the present invention, the bonding step of bonding the surface of the first semiconductor substrate and the surface of the second semiconductor substrate on the concave side is performed in a vacuum atmosphere. Accordingly, the concave portion is closed, and the pressure reference chamber in a reduced pressure state is formed accordingly. Also in this case, since the bonding step is performed while applying a temperature equal to or higher than the actual maximum use temperature of the semiconductor pressure sensor, water molecules attached or absorbed on the inner wall of the pressure reference chamber or the like are expelled. become.

After performing such a bonding step,
Along with the removal of the supporting substrate of the second semiconductor substrate by grinding, polishing or etching using the buried oxide film as a stopper, and the removal of the buried oxide film by selective etching, The semiconductor layer is exposed and a diaphragm can be formed at a position corresponding to the pressure reference chamber. In this case, the thickness dimension of the diaphragm depends on the depth position of the buried oxide film formed on the second semiconductor substrate side, and the thickness dimension of the diaphragm can be managed with high accuracy.

In the manufacturing method according to the ninth aspect, the first method
A bonding step of bonding the surface of the semiconductor substrate and the surface on the concave side of the second semiconductor substrate to each other is performed while applying a temperature equal to or higher than the actual maximum use temperature of the semiconductor pressure sensor according to the atmosphere in a vacuum state. Accordingly, water molecules attached or absorbed to the inner wall of the pressure reference chamber formed by the concave portion are expelled.

After performing such a bonding step,
Along with the execution of the selective removal step of peeling the second semiconductor substrate at the defect layer portion formed by the ion implantation layer formed thereon, the semiconductor layer located between the ion implantation layer and the buried oxide film is exposed. Thus, a diaphragm can be formed at a position corresponding to the pressure reference chamber. In this case, the thickness of the diaphragm depends on the depth positions of the buried oxide film and the ion-implanted layer formed on the second semiconductor substrate side, and the thickness of the diaphragm is controlled with high precision. Will be possible.

According to the manufacturing method of the tenth aspect, the first
A configuration in which the bonding step of bonding the surface of the semiconductor substrate and the surface on the concave side of the second semiconductor substrate to each other is performed after performing an activation process of irradiating the bonded surface of each of the semiconductor substrates with negative active gas ions. Therefore, there is no danger of water molecules remaining in the pressure reference chamber as in the case where bonding is performed after performing a hydrophilic treatment on the bonding surface, and the semiconductor pressure sensor is actually used. In this case, there is no possibility that the pressure in the pressure reference chamber increases due to the influence of water molecules.

According to the manufacturing method of the present invention, since the thickness of the diaphragm is determined depending on the epitaxial growth amount of the semiconductor layer, the thickness of the diaphragm can be accurately controlled. As a result, the detection sensitivity can be stabilized.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. FIG. 2 is a schematic sectional view showing the basic structure of a semiconductor pressure sensor manufactured by the method according to the present embodiment. In FIG. 2, the semiconductor pressure sensor 1 includes:
For example, N 2 is formed on a silicon substrate 2 through a silicon oxide film 3.
Having an SOI structure in which a single-crystal silicon layer 4 is formed. A diaphragm 5 formed in the single-crystal silicon layer 4 and a back side of the diaphragm 5 (between the diaphragm 5 and the silicon oxide film 3) are decompressed. A pressure reference chamber 6 formed in this state and a gauge resistor 7 formed on the diaphragm 5 by impurity diffusion are provided. In FIG. 2, components such as electrodes and wirings are omitted.

FIG. 1 shows a semiconductor pressure sensor 1 having the above configuration.
Is shown in a schematic cross-sectional view, which will be described below. First, as shown in FIG. 1A, on a silicon wafer 8 (corresponding to a support substrate in the present invention), a single-crystal silicon layer 9 (semiconductor in the present invention) which will eventually become the single-crystal silicon layer 4 is formed. An SOI substrate 11 (corresponding to a second semiconductor substrate), on which a layer (corresponding to a layer) is formed via an insulating separation film 10, and a silicon wafer 12 (corresponding to a first semiconductor substrate) are prepared. This silicon wafer 12
Is to be the silicon substrate 2 finally. On the upper surface thereof, a recess 13 for the pressure reference chamber 6 is formed, and a silicon oxide film 14 corresponding to the silicon oxide film 3 is formed. It is formed by a thermal oxidation method.
The silicon oxide film 14 is formed in a relatively thick state (for example, 1 μm or more) so as to be able to absorb excess water molecules. The surface of the single crystal silicon layer 9 on the SOI substrate 11 side and the surface of the silicon oxide film 14 on the silicon wafer 12 side are mirror-finished.

Next, by performing a bonding step, processing is performed to a state shown in FIG. This bonding step is performed by a known direct bonding method. First, the surface of the single-crystal silicon layer 9 on the SOI substrate 11 side and the surface of the silicon oxide film 14 on the silicon wafer 12 side are subjected to a hydrophilic treatment (for example, A mixed solution of sulfuric acid and hydrogen peroxide solution (H2SO4: H2O2 = 4:
After sequentially performing the cleaning in 1) and the pure water cleaning, a process of controlling the amount of water adsorbed on the surface by, for example, spin drying is performed. Then, after that, the SOI substrate 11 and the silicon wafer 12 are bonded to each other while being brought into close contact with each other on the surface subjected to the hydrophilic treatment, and the bonding is performed while applying a relatively low temperature to the work in a vacuum atmosphere. Do. However, the heat treatment temperature in such a bonding step is set to a temperature higher than the actual maximum use temperature of the semiconductor pressure sensor 1 (for example, 200 ° C. for an automobile).

As described above, the bonding step of the SOI substrate 11 and the silicon wafer 12 is performed while applying a predetermined temperature in a vacuum atmosphere, and as a result, the bonding to the inner wall of the concave portion 13 which finally becomes the pressure reference chamber 6 is performed. The absorbed gas (including moisture) is expelled to the outside, and the pressure reference chamber 6 is formed in a reduced pressure state.

After performing the above-described bonding step, a selective removing step is performed. Specifically, in this selective removal step, the silicon wafer 8 on the SOI substrate 11 side is removed by performing grinding, polishing, chemical etching, or the like using the insulating separation film 10 as a stopper, and FIG. As shown, the insulating separation film 10 is exposed. Thereafter, the insulating separation film 10 is removed by chemical etching using, for example, a hydrofluoric acid-based aqueous solution or selective etching such as chemical mechanical polishing or dry etching, and as shown in FIG. The diaphragm 5 is formed by exposing the surface of the crystalline silicon layer 9.

Then, as shown in FIG. 1E, a diffusion step of forming a gauge resistor 7 by diffusing, for example, a P-type impurity at a predetermined position in the single crystal silicon layer 9 is performed. After performing a well-known process of forming a single crystal silicon layer 9 and a silicon wafer 12, the integrated material such as the
The basic structure of the semiconductor pressure sensor 1 as shown in FIG.

According to the manufacturing method of the present embodiment, the bonding step of bonding the SOI substrate 11 and the silicon wafer 12 by the direct bonding method is performed in a vacuum atmosphere at a relatively low temperature. , Water molecules attached or absorbed in the pressure reference chamber 6 and the like are expelled. For this reason, when the semiconductor pressure sensor 1 is used in an atmosphere accompanied by a temperature rise, it is possible to prevent a situation in which the pressure inside the pressure reference chamber 6 fluctuates due to the presence of water molecules and the detection sensitivity becomes unstable. Become like

In this case, the heat treatment temperature in the bonding step is set to a temperature higher than the actual maximum use temperature of the semiconductor pressure sensor 1 (for example, 200 ° C. for an automobile). The pressure in the pressure reference chamber 6 can be stabilized when the device 1 is actually used, and the situation in which the detection sensitivity becomes unstable can be reliably prevented. In addition, the thickness of the diaphragm 5 depends on the thickness of the single-crystal silicon layer 9 provided in advance on the SOI substrate 11 side, so that the thickness of the diaphragm 5 can be managed with high precision. Therefore, it is possible to generally improve the pressure detection accuracy of the diaphragm 5.

Further, according to the semiconductor pressure sensor 1 manufactured by the method of the present embodiment, the predetermined thickness (for example, 1 μm or more)
Since the silicon oxide film 3 is disposed so as to face the inside of the pressure reference chamber 5, the silicon oxide film 3 can absorb excess water molecules. Therefore, even when water molecules remain in the pressure reference chamber 5,
A situation in which the pressure in the pressure reference chamber 5 fluctuates due to the influence of water molecules can be suppressed, which can contribute to an improvement in pressure detection accuracy.

In the above embodiment, after exposing the surface of the single crystal silicon layer 9 by performing the selective removal step,
The single crystal silicon layer 9 may be epitaxially grown to control the thickness dimension of the diaphragm 5 to perform an epitaxial growth step. According to this configuration, the thickness dimension of the diaphragm 5 can be accurately controlled by the amount of epitaxial growth of the single crystal silicon layer 9, so that the detection sensitivity of the semiconductor pressure sensor 1 can be stabilized.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
Only parts different from the embodiment will be described. First, as shown in FIG. 3A, an SOI substrate 11 having a single crystal silicon layer 9 formed on a silicon wafer 8 with an insulating separation film 10 interposed therebetween,
The silicon wafer 12 having the concave portion 13 is prepared, and a bonding process is performed in an atmosphere in a vacuum state to process the silicon wafer 12 to a state shown in FIG. In this case, the surface of the SOI substrate 11 on the side of the single crystal silicon layer 9 and the surface of the silicon wafer 12 on the side of the concave portion 13 are irradiated with negative active gas ions, for example, argon ions to uniformly etch each surface. After performing an activation process for making the entire surface active, the SOI substrate 1
And the silicon wafer 12 are bonded together on the activation processing surface. Note that such a bonding step is performed in an atmosphere in a vacuum state, whereby the pressure inside the pressure reference chamber 6 formed by the recess 13 is reduced.

After the above-described bonding step is performed, the same selective removing step as in the first embodiment (FIG. 3)
(C) and (d)) and a diffusion step (see FIG. 3 (e)) for forming the gauge resistor 7 are sequentially performed, and then a dicing process is performed to complete the basic structure of the semiconductor pressure sensor. Let it.

According to the manufacturing method of the present embodiment, S
Since the bonding process for bonding the OI substrate 11 and the silicon wafer 12 is performed after performing an activation process of irradiating the bonding surface with argon ions, the bonding surface is made hydrophilic. As in the manufacturing method in which the bonding is performed after the treatment, there is no possibility that water molecules remain in the pressure reference chamber 6, and when the semiconductor pressure sensor is actually used, the pressure reference is affected by the water molecules. There is no danger that the pressure in the chamber 6 will rise.

Therefore, according to the manufacturing method of this embodiment,
As described above, the situation in which the pressure in the pressure reference chamber 6 fluctuates due to the influence of water molecules can be prevented beforehand, and the thickness dimension of the diaphragm 5 can be managed with high precision similarly to the first embodiment. Therefore, it is possible to generally improve the pressure detection accuracy of the diaphragm 5. Also in this embodiment, after the surface of the single-crystal silicon layer 9 is exposed by performing the selective removal process,
May be configured to execute an epitaxial growth step of controlling the thickness of the diaphragm 5 by epitaxial growth.

(Third Embodiment) FIG. 4 shows a third embodiment of the present invention.
Only parts different from the embodiment will be described. First, as shown in FIG. 4A, the buried oxide film 1 is located at a predetermined depth from the surface side.
A single crystal silicon wafer 16 (corresponding to a second semiconductor substrate) in which 5 is partially formed and a silicon wafer 12 in which a concave portion 13 is formed are prepared. In this case, the thin-film region on the surface of the single-crystal silicon wafer 16 divided by the buried oxide film 15 functions as a single-crystal silicon layer 16a corresponding to the semiconductor layer in the present invention. The buried oxide film 15 is formed by performing heat treatment after implanting oxygen ions into the wafer 16.
It is formed by MOX technology.

Next, by performing a bonding step, processing is performed to a state shown in FIG. This bonding step is performed by the same direct bonding method as in the first embodiment. First, the single-crystal silicon layer 1 on the single-crystal silicon wafer 16 side is used.
After the same hydrophilic treatment as that of the first embodiment is performed on the surface of the silicon wafer 12 and the surface of the silicon wafer 12 on the side of the concave portion 13, the silicon wafers 12 and 16 are adhered to each other on the hydrophilic treatment surface. This bonding is performed in a vacuum atmosphere while applying a relatively low temperature to the work. However, also in this case, the heat treatment temperature in the bonding step is set to a temperature higher than the actual maximum use temperature of the semiconductor pressure sensor (for example, 200 ° C. for an automobile).

After forming the pressure reference chamber 6 in accordance with the execution of the above-described bonding step, a selective removal step is performed. Specifically, in the selective removal step, the silicon wafer 16 is subjected to grinding or polishing from the back side using the buried oxide film 15 as a stopper, and as shown in FIG. The film 15 is exposed. In this case, it is also possible to perform an etching process at the beginning and switch to a grinding or polishing process in the middle. Thereafter, the buried oxide film 15 is removed by, for example, chemical etching using a hydrofluoric acid-based aqueous solution or by selective etching such as chemical mechanical polishing or dry etching (see FIG. 4D). As a result, the silicon wafer 16 is removed leaving the single crystal silicon layer 16a, and the diaphragm 5 is formed by the single crystal silicon layer 16a.

After the selective removal step is performed, a diffusion step (see FIG. 4E) for forming the gauge resistor 7 similar to that of the first embodiment is sequentially performed, and then a dicing process is performed. This completes the basic structure of the semiconductor pressure sensor.

Therefore, according to the manufacturing method of this embodiment,
As in the first embodiment, at the time of execution of the bonding step, water molecules attached or absorbed in the pressure reference chamber 6 and the like are expelled, and the diaphragm 5
Thickness strictly depends on the thickness of the single-crystal silicon layer 16a (the position where the buried oxide film 16 is formed), and the thickness of the diaphragm 5 can be managed with high precision. Therefore, it is possible to generally improve the pressure detection accuracy of the diaphragm 5. Incidentally, also in this embodiment, the above-described epitaxial growth step is performed, or the first wafer is placed on the upper surface of the silicon wafer 12.
The configuration may be such that a silicon oxide film is formed in the same manner as in the embodiment. The bonding step may be performed by a method of irradiating with inert gas ions as in the second embodiment.

(Fourth Embodiment) FIG. 5 shows a fourth embodiment of the present invention.
Only parts different from the embodiment will be described. First, as shown in FIG. 5A, an N-type impurity diffusion layer 17 having a P-type impurity diffusion layer 17 is formed from the surface to a depth corresponding to the thickness of the single-crystal silicon layer 9 in the first embodiment. A single-crystal silicon wafer 18 (corresponding to a second semiconductor substrate) and a silicon wafer 12 having a recess 13 are prepared. In this case, as in the first embodiment, a silicon oxide film 14 is formed on the upper surface of the silicon wafer 12 by a thermal oxidation method.

Next, by performing a bonding step, processing is performed to a state shown in FIG. 5B. This bonding step is performed by the same direct bonding method as in the first embodiment. First, the surface of the single crystal silicon wafer 18 on the side of the impurity diffusion layer 17 and the surface of the silicon wafer 12 on the side of the concave portion 13 are
After the same hydrophilic treatment as in the first embodiment is performed, the two silicon wafers 12 and 18 are adhered to each other by being brought into close contact with the hydrophilic treatment surface. This bonding is performed in a vacuum atmosphere while applying a relatively low temperature to the work. However, also in this case, the heat treatment temperature in the bonding step is set to a temperature higher than the actual maximum use temperature of the semiconductor pressure sensor (for example, 200 ° C. for an automobile).

After forming the pressure reference chamber 6 in accordance with the execution of the above-described bonding step, a selective removal step is performed. Specifically, in this selective removal step, an etching process is performed on the silicon wafer 18 from the back side using the impurity diffusion layer 17 as a stopper, and as shown in FIG. The diaphragm 5 is formed to be exposed as a semiconductor layer in the present invention. The etching process in this case can be performed using, for example, a KOH-based alkali etching solution.

Then, after performing the above-mentioned selective removal step,
After sequentially performing a diffusion step (see FIG. 5D) for forming the gauge resistor 7 similar to that of the first embodiment,
The basic structure of the semiconductor pressure sensor is completed by performing dicing.

Therefore, according to the manufacturing method of this embodiment,
As in the first embodiment, at the time of execution of the bonding step, water molecules attached or absorbed in the pressure reference chamber 6 and the like are expelled, and the diaphragm 5
Is strictly dependent on the thickness of the impurity diffusion layer 17, and the thickness of the diaphragm 5 can be controlled with high precision. Therefore, the accuracy of pressure detection by the diaphragm 5 can be generally improved. Can be realized. still,
In this embodiment as well, the configuration may be such that the above-described epitaxial growth step is performed, and the bonding step is the same as in the second embodiment described above, on the assumption that the silicon oxide film 14 is not provided on the silicon wafer 12. It may be performed by a method of irradiating with an inert gas ion.

(Fifth Embodiment) FIG. 6 shows a fifth embodiment of the present invention.
Only parts different from the embodiment will be described. First, as shown in FIG. 6 (a), a hydrogen ion implanted layer 19 for forming crystal defects is formed from the surface side to a depth corresponding to the thickness of the single crystal silicon layer 9 in the first embodiment. Mold single crystal silicon wafer 20 (corresponding to the second semiconductor substrate) and concave portion 1
Then, a silicon wafer 12 on which 3 is formed is prepared. still,
In the single crystal silicon wafer 20, a thin film region located at a position shallower than the hydrogen ion implanted layer 19 functions as a single crystal silicon layer 20a corresponding to a semiconductor layer in the present invention. As in the first embodiment, a silicon oxide film 14 is formed on the upper surface of the silicon wafer 12.
Are formed by a thermal oxidation method.

In this case, as the ions forming the hydrogen ion implanted layer 19, besides the hydrogen ions, rare gas ions such as helium can be used. The dose is, for example, 1 × 10 ¹⁶ atoms / cm ² to 1 × 10 ¹⁷ atoms / cm ^2.
, Preferably 5 × 10 ¹⁶ atoms / cm ² to 1 × 10
^It is set in the range of ¹⁷ atoms / cm ² . Further, the ion implantation energy is set according to the depth at which the hydrogen ion implantation layer 19 is formed. Actually, prior to the ion implantation step, a contamination protection film is formed on the surface on the ion implantation side with a silicon oxide film or the like, and the contamination protection film is removed after the ion implantation step. Thereby, the mirror state of the surface of the single crystal silicon wafer 20 is maintained, and contamination by metal ions or the like is prevented.

Next, by performing a bonding step, processing is performed to a state shown in FIG. This bonding step is performed by the same direct bonding method as that of the first embodiment. First, the surface of the single crystal silicon wafer 20 on the ion implantation side and the surface of the silicon wafer 12 on the side of the concave portion 13 are attached to the first embodiment. After the same hydrophilic treatment as described above, both silicon wafers 12 and 20 are adhered to each other by being brought into close contact with the above-mentioned hydrophilic treatment surface. This bonding is performed in a vacuum atmosphere while applying a relatively low temperature to the work. However, also in this case, the heat treatment temperature in the bonding step is set to a temperature higher than the actual maximum use temperature of the semiconductor pressure sensor (for example, 200 ° C. for an automobile), but hydrogen This is performed at a temperature lower than the temperature (about 400 ° C.) at which the separation phenomenon starts in the ion implantation layer 19.

After the pressure reference chamber 6 is formed in accordance with the execution of the above-described bonding step, a selective removal step is performed. More specifically, in this selective removal step, the silicon wafer 20 is subjected to a heat treatment at about 400 ° C. to 600 ° C. on the integrated body of the silicon wafers 12 and 20 so that the silicon wafer 20 becomes a defect layer The single-crystal silicon layer 20a is exposed by exfoliating the portion, thereby forming the diaphragm 5. Note that the surface of the single crystal silicon layer 20a is subjected to a flattening process such as polishing as necessary. Further, in the above-described peeling phenomenon, micro bubbles are aggregated in a defect layer portion formed by the hydrogen ion implanted layer 19 due to heat treatment to generate macro bubbles, and thereby the defect layer portion becomes a boundary. The peeling is caused by enlargement, and therefore, the single-crystal silicon layer 2
The thickness dimension of 0a depends on the depth position of the hydrogen ion implanted layer 19 (that is, the ion implantation depth in the ion implantation step).

Then, after performing the selective removal step,
After sequentially performing a diffusion step (see FIG. 6D) for forming the gauge resistor 7 similar to that of the first embodiment,
The basic structure of the semiconductor pressure sensor is completed by performing dicing.

Therefore, according to the manufacturing method of this embodiment,
As in the first embodiment, at the time of execution of the bonding step, water molecules attached or absorbed in the pressure reference chamber 6 and the like are expelled, and the diaphragm 5
Is strictly dependent on the depth position of the hydrogen ion implanted layer 19 (the ion implantation depth in the ion implantation step), and the thickness of the diaphragm 5 can be managed with high precision. Therefore, it is possible to generally improve the pressure detection accuracy of the diaphragm 5. In this embodiment, the epitaxial growth step as described above may be performed, and the bonding step is performed on the assumption that the silicon oxide film 14 is not provided on the silicon wafer 12 in the second embodiment. It may be performed by a method of irradiating inert gas ions as described above.

(Sixth Embodiment) FIG. 7 shows a sixth embodiment of the present invention.
Only parts different from the embodiment will be described. First, as shown in FIG. 7A, a single crystal silicon layer 22 (corresponding to a semiconductor layer according to the present invention) is formed on a silicon wafer 21 (corresponding to a supporting substrate according to the present invention) via an insulating separation film 23. S formed
An OI substrate 24 (corresponding to a second semiconductor substrate) is prepared, and FIG.
As shown in (b), an oxide film forming step of forming a buried oxide film 25 at a predetermined depth position of the single crystal silicon layer 22 by using the SIMOX technique is performed. in this case,
In the single crystal silicon layer 22, a thin film surface side region divided by the buried oxide film 25 is a portion that finally becomes the diaphragm 5. Further, as shown in FIG. 7C, a recess forming step of forming a recess 26 reaching the buried oxide film 25 is performed on the surface side region of the single crystal silicon layer 22, and a predetermined film thickness is formed on the surface. Wafer 28 having a silicon oxide film 27 formed by thermal oxidation
(Corresponding to the first semiconductor substrate) is prepared.

Next, by performing a bonding step, processing is performed to a state shown in FIG. This bonding step is performed by the same direct bonding method as that of the first embodiment. First, the surface of the SOI substrate 24 on the side of the concave portion 26 and the surface of the silicon wafer 28 on the side of the silicon oxide film 27 are first formed. After performing the same hydrophilic treatment as described above, the SOI substrate 24 and the silicon wafer 28 are closely attached to each other on the above-mentioned hydrophilic treatment surface and bonded. This bonding is performed in a vacuum atmosphere while applying a relatively low temperature to the work. However, also in this case, the heat treatment temperature in the bonding step is set to a temperature higher than the actual maximum use temperature of the semiconductor pressure sensor (for example, 200 ° C. for an automobile).

After forming the pressure reference chamber 6 in accordance with the execution of the above-described bonding step, a selective removal step is performed. Specifically, in this selective removal step, the SOI substrate 2
The silicon wafer 21 on the fourth side is removed by performing grinding, polishing, and chemical etching using the insulating separation film 23 as a stopper, and after exposing the insulating separation film 23, the insulating separation film 23 is removed, for example. As shown in FIG.
As shown in (e), the surface of the single-crystal silicon layer 22 is exposed to form the diaphragm 5. In the case of this embodiment, the buried oxide film 25 is left between the diaphragm 5 and the pressure reference chamber 6.

Then, after performing the above-mentioned selective removal step,
After sequentially performing a diffusion step (see FIG. 7F) for forming the gauge resistor 7 similar to that of the first embodiment,
The basic structure of the semiconductor pressure sensor is completed by performing dicing.

Therefore, according to the manufacturing method of this embodiment,
As in the first embodiment, at the time of execution of the bonding step, water molecules attached or absorbed in the pressure reference chamber 6 and the like are expelled, and the diaphragm 5
Is strictly dependent on the thickness dimension (depth position of the buried oxide film 25) of the thin film region divided by the buried oxide film 25 in the single crystal silicon layer 22, Since the thickness dimension of the diaphragm 5 can be managed with high accuracy, it is possible to generally improve the pressure detection accuracy of the diaphragm 5. In this embodiment, the epitaxial growth step as described above may be performed. In the bonding step, it is assumed that the silicon oxide film 27 is not provided on the silicon wafer 28. It is good also as a structure which performs by the technique of irradiating inert gas ions like this.

(Seventh Embodiment) FIG. 8 shows a seventh embodiment of the present invention in which the above-described sixth embodiment is partially modified, and only different portions will be described below. . That is, in this embodiment, instead of the oxide film forming step for forming the buried oxide film 25 in the sixth embodiment, a SO
The buried oxide film 29 is partially formed at a predetermined depth position of the single crystal silicon layer 22 on the I-substrate 24 by using the SIMOX technique.
(See FIG. 8B). Also in this case, the thin-film surface-side region of the single-crystal silicon layer 22 divided by the buried oxide film 29 finally becomes the diaphragm 5. Further, as shown in FIG. 8C, a recess forming step of forming a recess 26 reaching the buried oxide film 29 is performed on the single crystal silicon layer 22, and a silicon oxide film 27 is formed on the surface by thermal oxidation. Formed silicon wafer 2
8 are prepared, and thereafter, the bonding step, the selective removing step, and the diffusion step (FIGS. 8D, 8E,
(Refer to (f)), and the like, and then dicing is performed to complete the basic structure of the semiconductor pressure sensor.

Incidentally, also in this embodiment, the structure for executing the epitaxial growth step as described above may be adopted.
Further, the bonding step may be performed by a method of irradiating with inert gas ions as in the second embodiment on the assumption that the silicon oxide film 27 is not provided on the silicon wafer 28.

(Eighth Embodiment) FIG. 9 shows an eighth embodiment of the present invention.
Only parts different from the embodiment will be described. First, as shown in FIG. 9A, a single crystal silicon wafer 30 (corresponding to a second semiconductor substrate) is prepared, and a SIMOX technique is used at a position at a predetermined depth from the surface side of the single crystal silicon wafer 30. To form a buried oxide film 31. Next, as shown in FIG. 9B, an ion implantation step of forming a hydrogen ion implantation layer 32 for forming crystal defects reaching a predetermined depth from the surface side of the single crystal silicon wafer 30 is performed. in this case,
Hydrogen ion implanted layer 3 in single crystal silicon wafer 30
The thin film region existing between the second oxide film 31 and the buried oxide film 31 functions as a single crystal silicon layer 30a corresponding to the semiconductor layer in the present invention. The ion implantation depth at this time is set so that the thickness of the single crystal silicon layer 30a has a value corresponding to the thickness of the diaphragm. The dose of hydrogen ions in the ion implantation step may be set in the same manner as in the fifth embodiment.

Next, as shown in FIG. 9C, a recess forming step of forming a recess 33 reaching the buried oxide film 31 is performed on the single crystal silicon wafer 30 and a silicon film having a predetermined thickness is formed on the surface. A silicon wafer 28 having an oxide film 27 formed by thermal oxidation is prepared.

Next, by performing a bonding step, processing is performed to a state shown in FIG. 9D. This bonding step is performed by the same direct bonding method as in the first embodiment. First, the first surface of the single crystal silicon wafer 30 on the side of the concave portion 33 and the surface of the silicon wafer 28 on the side of the silicon oxide film 27 are firstly bonded. After performing the same hydrophilic treatment as that of the embodiment, the silicon wafers 30 and 28 are adhered to each other by being brought into close contact with the hydrophilic treatment surface. This bonding is performed in a vacuum atmosphere while applying a relatively low temperature to the work. However, even in this case, the heat treatment temperature in the bonding step is set to a temperature higher than the actual maximum use temperature of the semiconductor pressure sensor (for example, 200 ° C. for an automobile). This is performed at a temperature lower than the temperature (about 400 ° C.) at which the separation phenomenon starts in the hydrogen ion implanted layer 32. .

After the pressure reference chamber 6 is formed in accordance with the execution of the above-described bonding step, a selective removal step is performed. Specifically, in this selective removal step, a single crystal silicon wafer 30 is formed by the hydrogen ion implanted layer 32 by performing a heat treatment at about 400 ° C. to 600 ° C. on the integrated body of the silicon wafers 30 and 28. The single crystal silicon layer 30a is exposed by peeling off at the defective layer portion, thereby forming the diaphragm 5. Note that the surface of the single crystal silicon layer 30a is subjected to a flattening process such as polishing if necessary.

Then, after performing the selective removal step,
After sequentially performing a diffusion step (see FIG. 9F) for forming the gauge resistor 7 similar to that of the first embodiment,
The basic structure of the semiconductor pressure sensor is completed by performing dicing.

Therefore, according to the manufacturing method of this embodiment,
As in the first embodiment, at the time of execution of the bonding step, water molecules attached or absorbed in the pressure reference chamber 6 and the like are expelled, and the diaphragm 5
The thickness dimension of the diaphragm 5 is strictly dependent on the depth position of the hydrogen ion implanted layer 32, and the thickness dimension of the diaphragm 5 can be controlled with high accuracy. Improvements can be realized.
In this embodiment, the epitaxial growth step may be performed as described above. The bonding step may include the step of forming the silicon oxide film 2 on the silicon wafer 28.
7 may be performed by a method of irradiating with inert gas ions as in the second embodiment on the premise that no 7 is provided.

(Ninth Embodiment) FIG. 10 shows a ninth embodiment of the present invention in which the above-described eighth embodiment is partially modified, and only different portions will be described below. . That is, in this embodiment, the buried oxide film 34 is partially formed at a predetermined depth position in the single crystal silicon wafer 30 by using the SIMOX technique instead of the buried oxide film 31 in the eighth embodiment. (See FIG. 8A). Then, as shown in FIG. 10B, an ion implantation step of forming a hydrogen ion implantation layer 32 for forming a crystal defect reaching a predetermined depth from the surface side of the single crystal silicon wafer 30 is similarly performed. Also in this case, the thin film region existing between the hydrogen ion implanted layer 32 and the buried oxide film 34 in the single crystal silicon wafer 30 functions as the single crystal silicon layer 30a that finally becomes the diaphragm 5. I have. Further, as shown in FIG. 10C, the buried oxide film 3
4 and a silicon wafer 28 having a silicon oxide film 27 formed on the surface by thermal oxidation is prepared, and thereafter, a bonding step similar to that of the eighth embodiment is performed. After the removal step and the diffusion step (see FIGS. 10D, 10E, and 10F) are sequentially performed, dicing is performed to complete the basic structure of the semiconductor pressure sensor.

Incidentally, also in this embodiment, the structure for executing the epitaxial growth step as described above may be adopted.
Further, the bonding step may be performed by a method of irradiating with inert gas ions as in the second embodiment on the assumption that the silicon oxide film 27 is not provided on the silicon wafer 28.

(Other Embodiments) The present invention is not limited to the above-described embodiment, but can be modified or expanded as follows. In each embodiment, after the execution of the bonding step, a heat treatment step (for example, a high temperature (about 1100 ° C. to 1200 ° C. or more) in an atmosphere of an inert gas such as nitrogen) is applied as necessary to increase the bonding strength. Heat treatment). The silicon oxide film for functioning as a stopper during polishing or etching can be replaced with a polycrystalline silicon film. The technique for obtaining the buried oxide film in each embodiment is not limited to the SIMOX technique, and various other techniques such as a bonding technique, a lateral epitaxial growth technique, and a laser recrystallization technique can be used.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a manufacturing method according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a basic structure of a semiconductor pressure sensor.

FIG. 3 is a sectional view schematically showing a manufacturing method according to a second embodiment of the present invention.

FIG. 4 is a sectional view schematically showing a manufacturing method according to a third embodiment of the present invention.

FIG. 5 is a sectional view schematically showing a manufacturing method according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view schematically showing a manufacturing method according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view schematically showing a manufacturing method according to a sixth embodiment of the present invention.

FIG. 8 is a sectional view schematically showing a manufacturing method according to a seventh embodiment of the present invention.

FIG. 9 is a sectional view schematically showing a manufacturing method according to an eighth embodiment of the present invention.

FIG. 10 is a sectional view schematically showing a manufacturing method according to a ninth embodiment of the present invention.

[Explanation of symbols]

1 is a semiconductor pressure sensor, 2 is a silicon substrate, 3 is a silicon oxide film, 4 is a single crystal silicon layer, 5 is a diaphragm,
6 is a pressure reference chamber, 7 is a gauge resistor, 8 is a silicon wafer (support substrate), 9 is a single crystal silicon layer (semiconductor layer), 1
0 is an insulating separation film, 11 is an SOI substrate (second semiconductor substrate), 12 is a silicon wafer (first semiconductor substrate), 13
Is a recess, 14 is a silicon oxide film, 15 is a buried oxide film, 1
6 is a single crystal silicon wafer (second semiconductor substrate), 16a
Is a single crystal silicon layer (semiconductor layer), 17 is an impurity diffusion layer, 18 is a single crystal silicon wafer 18 (second semiconductor substrate), 19 is a hydrogen ion implanted layer, 20 is a single crystal silicon wafer (second semiconductor substrate), 20a is a single crystal silicon layer (semiconductor layer), 21 is a silicon wafer (support substrate), 2
2 is a single crystal silicon layer (semiconductor layer), 23 is an insulating separation film, 24 is an SOI substrate (second semiconductor substrate), 25 is a buried oxide film, 26 is a concave portion, 27 is a silicon oxide film, and 28 is a silicon wafer ( A first semiconductor substrate), 29 is a buried oxide film,
30 is a single crystal silicon wafer (second semiconductor substrate), 30
a indicates a single crystal silicon layer (semiconductor layer), 31 indicates a buried oxide film, 32 indicates a hydrogen ion implanted layer, 33 indicates a concave portion, and 34 indicates a buried oxide film.

Claims (11)

[Claims] 1. A method for manufacturing a semiconductor pressure sensor comprising a depressurized pressure reference chamber on the back side of a diaphragm, wherein a first concave portion for forming the pressure reference chamber is provided.
After preparing a semiconductor substrate and a second semiconductor substrate provided with a semiconductor layer for forming the diaphragm on the front side, a surface of the first semiconductor substrate on the concave side and a semiconductor of the second semiconductor substrate After subjecting the layer side surface to hydrophilic treatment,
A bonding step of bonding them to each other on the hydrophilized surface is performed in a vacuum atmosphere while applying a temperature equal to or higher than the actual maximum use temperature of the semiconductor pressure sensor. A method for manufacturing a semiconductor pressure sensor, comprising: performing a selective removal step of selectively removing a portion other than a semiconductor layer to expose the semiconductor layer and form the diaphragm. 2. The method for manufacturing a semiconductor pressure sensor according to claim 1, wherein an oxide film is formed with a predetermined thickness on the surface of the first semiconductor substrate on the side of the concave portion. 3. A method of manufacturing a semiconductor pressure sensor comprising a depressurized pressure reference chamber on the back side of a diaphragm, wherein a first concave portion for forming the pressure reference chamber is provided.
After preparing a semiconductor substrate and a second semiconductor substrate provided with a semiconductor layer for forming the diaphragm on the front side, a surface of the first semiconductor substrate on the concave side and a semiconductor of the second semiconductor substrate After performing an activation process of irradiating the layer side surface with negative active gas ions, a bonding step of bonding them to each other on the activation processing surface is performed in an atmosphere in a vacuum state. A method for manufacturing a semiconductor pressure sensor, comprising: performing a selective removal step of selectively removing a portion of a semiconductor substrate other than the semiconductor layer to expose the semiconductor layer and form the diaphragm. 4. The second semiconductor substrate is formed by an SOI substrate having a semiconductor layer formed on a supporting substrate via an insulating separation film, and in the selective removing step, the supporting substrate is formed by using the insulating separating film as a stopper. 4. The method according to claim 1, wherein said insulating separation film is removed by a selective etching process after removing by said grinding, polishing or etching process.
The method for manufacturing a semiconductor pressure sensor according to any one of the above. 5. A state in which the buried oxide film is formed at a position at a predetermined depth from the surface side of the second semiconductor substrate, so that the surface of the second semiconductor substrate is divided by the buried oxide film. In the selective removal step, the second semiconductor substrate is subjected to a grinding or polishing process from the back side using the buried oxide film as a stopper, and then the buried oxide film is formed. 4. The method of manufacturing a semiconductor pressure sensor according to claim 1, wherein the semiconductor layer is removed by selective etching. 6. The second semiconductor substrate has a structure in which an impurity diffusion layer reaching a depth corresponding to a thickness of the semiconductor layer is formed from a surface side of the second semiconductor substrate. The semiconductor pressure sensor according to any one of claims 1 to 3, wherein the impurity diffusion layer is exposed as the semiconductor layer by performing an etching process on the back surface side using the impurity diffusion layer as a stopper. Manufacturing method. 7. The second semiconductor substrate, wherein an ion implantation layer for forming a crystal defect is formed at a position at a predetermined depth from the surface side, and a region located at a position shallower than the ion implantation layer is formed as the semiconductor layer. In the selective removal step, the second semiconductor substrate is peeled at a defect layer portion formed by the ion implantation layer to expose the semiconductor layer by performing a heat treatment. Item 4. The method for manufacturing a semiconductor pressure sensor according to any one of Items 1 to 3. 8. A method for manufacturing a semiconductor pressure sensor comprising a depressurized pressure reference chamber on the back side of a diaphragm, wherein a semiconductor layer is formed on a first semiconductor substrate and a support substrate via an insulating separation film. An oxide film forming step of preparing a buried oxide film at a position at a predetermined depth from the surface side of the semiconductor layer of the second semiconductor substrate after preparing a second semiconductor substrate made of the SOI substrate described above; A recess forming step of forming a recess reaching the buried oxide film is sequentially performed on the semiconductor layer of the second semiconductor substrate, and the recess is formed on the surface of the first semiconductor substrate and the surface of the second semiconductor substrate on the recess side. After performing the hydrophilic treatment, a bonding step of bonding them together on the hydrophilic treatment surface,
The process is performed in a vacuum atmosphere while applying a temperature equal to or higher than the actual maximum operating temperature of the semiconductor pressure sensor. Thereafter, the supporting substrate of the second semiconductor substrate is ground, polished or etched using the buried oxide film as a stopper. Forming a diaphragm by exposing the semiconductor layer by performing a selective removal step of removing the buried oxide film by a selective etching process after the removal by the treatment. . 9. A method of manufacturing a semiconductor pressure sensor comprising a depressurized pressure reference chamber on the back side of a diaphragm, wherein a first semiconductor substrate and a buried oxide film are formed at a predetermined depth position. After preparing the second semiconductor substrate, an ion implantation layer for forming a crystal defect is formed at a position deeper than the buried oxide film by ion-implanting the second semiconductor substrate from the surface side thereof. An ion implantation step in which a region between the ion implantation layer and the buried oxide film is used as a semiconductor layer; and a recess forming step of forming a recess reaching the buried oxide film from the surface side of the second semiconductor substrate. Performing a hydrophilizing process on the surface of the first semiconductor substrate and the concave-side surface of the second semiconductor substrate, and then laminating them on the hydrophilizing surface,
The process is performed in a vacuum atmosphere while applying a temperature equal to or higher than the actual maximum use temperature of the semiconductor pressure sensor, and thereafter, a heat treatment is performed to thereby convert the second semiconductor substrate into a defect layer portion formed by the ion implantation layer. A method for manufacturing a semiconductor pressure sensor, wherein the semiconductor layer is exposed to form the diaphragm by performing a selective removing step of peeling off the semiconductor layer. 10. The method of manufacturing a semiconductor pressure sensor according to claim 8, wherein the surface of the first semiconductor substrate and the surface of the second semiconductor substrate on the concave side are replaced with a negative active gas instead of the bonding step. After performing an activation process of irradiating ions, a bonding step of bonding the first semiconductor substrate and the second semiconductor substrate to each other on the activation processing surface in a vacuum atmosphere is performed. Manufacturing method of pressure sensor. 11. The method according to claim 11, further comprising:
The semiconductor pressure according to any one of claims 1 to 10, wherein after exposing the semiconductor layer of the semiconductor substrate, the semiconductor layer is epitaxially grown to perform an epitaxial growth step of controlling a thickness dimension of the diaphragm. Manufacturing method of sensor.