JP2002222961A - Method for manufacturing vacuum container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve vacuum degree of a vacuum space 6 of a vacuum container 1. SOLUTION: A method for manufacturing the vacuum container comprises the steps of coupling a semiconductor substrate 3 to an upper side of a base 2, thinning the substrate 3, thereafter processing the substrate 3. The method further comprises the step of thereafter dipping a connector of the base 2 to the substrate 3 in a mixed aqueous solution of a hydrogen fluoride and a copper chloride. Thus, nonmetallic atoms such as oxygen atoms or the like coupled to the surface of the substrate 3 are removed by the hydrogen fluoride to expose the surface of the substrate 3, and the surface of the exposed substrate 3 is bonded to copper atoms in the mixed solution. The method also comprises the steps of anodizing a cover member 4 to the upper side of the substrate 3 in which the copper atoms are bonded. In this case, a generation of unnecessary gas from the anodized part is suppressed to a small value, and the vacuum space 6 can be hermetically sealed in a state in which the vacuum degree is good.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a vacuum container manufactured by using anodic bonding.

[0002]

2. Description of the Related Art FIG. 3 schematically shows an example of a vacuum vessel in a sectional view. The vacuum vessel 1 shown in FIG.
It is configured to include a base (for example, a glass substrate) 2, a semiconductor substrate 3 of silicon or the like, and a cover member (for example, a glass substrate) 4. The base 2, the semiconductor substrate 3, and the lid member 4 are sequentially laminated to form a laminate 5, and the base 2, the lid member 4,
Have recesses 2a, 4a formed at portions opposed to each other via the semiconductor substrate 3, respectively.
Thus, a vacuum space 6 is formed inside the laminate 5.

[0003] Inside the vacuum space 6, for example, a vibrating body 7 formed by processing the semiconductor substrate 3 is accommodated. The vibrating body 7 can be satisfactorily vibrated without being damped by being accommodated in the vacuum space 6.

FIG. 4 is a perspective view showing an example of a semiconductor substrate 3 on which a vibrating body is formed, together with a base 2.
The semiconductor substrate 3 shown in FIG. 4 is processed using a technique such as etching, and a sensor section 8 including the vibrating body 7 and a seal section 9 surrounding the sensor section 8 are formed on the semiconductor substrate 3. ing. The seal portion 9 includes the base 2 and the lid member 4.
And is anodically bonded to the base 2 and the lid member 4 from both the upper and lower sides shown in the figure to seal the vacuum space 6 for accommodating the sensor unit 8.

The sensor section 8 constitutes an angular velocity sensor, and has a rectangular vibrating body 7, a vibrating body supporting / fixing section 10 (10a, 10b, 10c, 10d), and an electrode supporting / fixing section 11 (11a, 11a, 11b). 11b), a detection electrode pad forming part 12, and a beam 13 (13a, 13b, 13c, 13).
d) and the comb-shaped movable electrode portion 14 (14a, 14b)
And a comb-shaped fixed electrode portion 15 (15a, 15b).

[0006] The vibrating body support fixing portion 10 (10a, 10a
b, 10c, 10d) and the electrode support fixing portion 11 (11a,
11b) and the detection electrode pad forming section 12 are anodically bonded to the base 2 and the lid member 4 and fixed. The vibrating body 7 is supported by the vibrating body supporting and fixing portions 10 (10a, 10b, 10b) by beams 13 (13a, 13b, 13c, 13d).
c, 10d). In addition, the comb-shaped movable electrode portion 14 extends from the edge of the vibrating body 7.
(14a, 14b) are formed so as to protrude along the X direction in FIG. 4. A comb-shaped fixed electrode portion 15 (15a, 15b) is supported and fixed to the movable electrode portion 14 with an interval therebetween. It extends from the portion 11 (11a, 11b) along the X direction.

The vibrating body 7 and the beam 13 (13a, 13b, 13c, 13c) are provided on the base 2 and the lid member 4, respectively.
Concave portions 2a and 4a as shown in FIG. 3 are formed in a portion facing d) and all of the movable electrode portions 14 (14a and 14b). The vibrating body 7 is formed by these recesses 2a and 4a.
The beam 13 (13a, 13b, 13c, 13d) and the movable electrode portion 14 (14a, 14b) are in a state of being floating with respect to the base 2 and the cover member 4 and are movable.

[0008] The vibrating body supporting and fixing portion 10 (10a, 10a
b, 10c, 10d) and the electrode support fixing portion 11 (11a,
An electrode pad (not shown), which is a metal film, is formed on each of the upper surfaces of the electrode pad forming portion 12b and the detection electrode pad forming portion 12. Through holes are respectively formed in the cover member 4 at portions facing the respective electrode pads, whereby the respective electrode pads are exposed to the outside, and are electrically connected to an external circuit by wire bonding or the like. Can be.

On the bottom surface of the concave portion 2a of the base 2, a detection electrode portion (not shown) is formed at a portion opposed to the vibrator 7 with a space therebetween. Further, a wiring pattern 16 for electrically connecting the detection electrode portion and the detection electrode pad forming portion 12 is formed on the base 2.

In the sensor section 8 shown in FIG. 4, for example, when a driving AC voltage is applied to the fixed electrode sections 15a and 15b from an external circuit, the fixed section between the fixed electrode section 15a and the movable electrode section 14a is fixed. Electrode 15b and movable electrode 14
The vibrating body 7 performs drive vibration in the X direction shown in FIG. 4 by changing the electrostatic force generated between the points b and b according to the AC voltage. When the vibrating body 7 is rotated around the Y axis in a state where the vibrating body 7 is vibrating, a Coriolis force in the Z direction is generated. This Coriolis force is applied to the vibrating body 7, which vibrates in the Z direction.

Due to the vibration of the vibrating body 7 in the Z direction, the distance between the vibrating body 7 and the detection electrode changes, and the capacitance between the vibrating body 7 and the detection electrode changes. This change in the capacitance is detected by the detection electrode section from the wiring pattern 16.
And the outside through the electrode pad, and the magnitude of the angular velocity of rotation around the Y axis can be detected based on the detected value.

A vibrating body 7 as shown in FIG.
An example of a manufacturing process of the vacuum vessel 1 containing the (sensor section 8) will be briefly described with reference to FIG. In FIG. 5, FIG.
The site | part corresponding to the AA part shown in FIG.

[0013] As shown in FIG.
a, and then, as shown in FIG. 5 (b), a semiconductor substrate 3 is arranged above the base 2 so as to cover the opening of the recess 2a. 3 is anodically bonded. Then, as shown in FIG. 5C, the semiconductor substrate 3 is thinned to a set thickness by, for example, surface grinding, and then the upper surface of the semiconductor substrate 3 is mirror-polished.

Thereafter, as shown in FIG. 5D, the semiconductor substrate 3 is processed into a pattern shape as shown in FIG. 4 by using a technique such as etching or photolithography.

Thereafter, the recess 4a and the plurality of through holes 1
The lid member 4 on which the substrate 8 is formed is disposed above the semiconductor substrate 3. At this time, the recess 4a faces the vibrator 7 with an interval therebetween, and the plurality of through holes 18 correspond to the corresponding vibrator support fixing portions 10 (10a, 10b,
10c, 10d) and the electrode support fixing portion 11 (11a, 11d).
b) and the lid member 4 so as to coincide with the formation position of the electrode pad formed on the upper surface of the detection electrode pad formation portion 12.
Is positioned above the semiconductor substrate 3. Then, the semiconductor substrate 3 and the cover member 4 are anodically bonded in a vacuum chamber in which vacuum evacuation is performed, and a vacuum space 6 is formed by the base 2, the semiconductor substrate 3 and the cover member 4. Is hermetically sealed.

Thus, the vacuum container 1 can be manufactured.

[0017]

By the way, when the lid member 4 is anodically bonded to the upper side of the semiconductor substrate 3 in the manufacturing process of the vacuum vessel 1 as described above, the anodic bonding of the semiconductor substrate 3 and the lid member 4 is performed. Unnecessary gas is generated from the portion, and the gas flows into the vacuum space 6, thus causing a problem that the vacuum state in the vacuum space 6 is deteriorated.

Further, since the amount of generation of the unnecessary gas varies, the degree of vacuum in the vacuum space 6 differs for each vacuum vessel 1. For example, in FIG. When the vibrating body 7 constituting the angular velocity sensor as shown in FIG. 1 is housed, the vibration state of the vibrating body 7 varies for each vacuum vessel 1 and the performance of the angular velocity sensor varies. Problems arise.

In order to solve such a problem, for example, a gas adsorbing substance is added together with the vibrator 7 to the vacuum space 6.
There has been proposed a method in which the unnecessary gas is adsorbed on the gas adsorbing material to avoid the deterioration of the vacuum degree and the variation in the vacuum degree of the vacuum space 6. However, the gas adsorbing material must be arranged for each vacuum space 6,
There is a problem that it takes time and effort. Further, in order to accommodate the gas adsorbing substance, the vacuum space 6 must be widened, which inevitably causes a problem that the vacuum vessel 1 becomes large.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to manufacture a small-sized vacuum vessel in which a vacuum space can be easily brought into a desired good vacuum state. To provide a manufacturing method.

[0021]

Means for Solving the Problems In order to achieve the above object, the present invention has the following structure to solve the above problems. That is, the first invention provides a vacuum vessel in which a vacuum space is formed inside a laminated body in which a semiconductor substrate is bonded to the upper side of a base and a lid member is anodically bonded to the upper side of the semiconductor substrate. A method of manufacturing,
After bonding the semiconductor substrate to the upper side of the base, non-metal atoms bonded to the surface of the semiconductor substrate are removed to expose the surface of the semiconductor substrate. In this state, the surface of the semiconductor substrate and the non-metallic surface are exposed. A metal atom having a higher degree of bonding with the surface of the semiconductor substrate than a degree of bonding with the metal atom is bonded to the exposed surface of the semiconductor substrate, and thereafter, the upper surface of the semiconductor substrate to which the metal atom is bonded. Anodic bonding of the lid member to the fin.

According to a second aspect of the present invention, there is provided the configuration of the first aspect, wherein the metal atom is a copper atom.

According to a third aspect of the present invention, there is provided the semiconductor device according to the first or second aspect, wherein the removing substance for removing nonmetallic atoms bonded to the surface of the semiconductor substrate is bonded to the surface of the semiconductor substrate. In a solution containing metal atoms for use, immersing the joined body of the base and the semiconductor substrate, removing the non-metallic atoms from the surface of the semiconductor substrate with the removing substance, and exposing the substrate by the processing. The process of bonding the metal atoms to the surface of the semiconductor substrate is performed in the same step.

According to a fourth aspect of the present invention, there is provided the configuration of the third aspect, wherein the removing substance is hydrogen fluoride.

In the invention having the above structure, for example, when the semiconductor substrate is a silicon substrate, the silicon atoms constituting the semiconductor substrate are very easily bonded to oxygen atoms (nonmetallic atoms). Without any special treatment,
Oxygen atoms are bonded to silicon atoms on the surface of the semiconductor substrate, and the upper portion of the semiconductor substrate is naturally oxidized.

In the present invention, after the semiconductor substrate is joined to the upper side of the base, the nonmetallic atoms such as the oxygen atoms bonded to the surface of the semiconductor substrate are removed to expose the surface of the semiconductor substrate. Then, in this state, metal atoms such as copper atoms are bonded to the surface of the semiconductor substrate. Thereafter, a lid member is anodically bonded to the upper surface of the semiconductor substrate to which the metal atom has been bonded. That is, the lid member is anodically bonded to the upper side of the semiconductor substrate in a state where non-metal atoms such as oxygen atoms are not bonded to the surface. Thus, a vacuum container is manufactured.

The vacuum state of the vacuum space in the vacuum container manufactured in this way is much better than the vacuum state in the vacuum space of the vacuum container manufactured by the conventional manufacturing method. Further, by manufacturing the vacuum container by the manufacturing method shown in the present invention, without containing the gas adsorbing substance in the vacuum space, it is possible to make the vacuum space a good vacuum state, Since the gas adsorbing substance does not need to be provided in the vacuum space, the labor and time required for manufacturing the vacuum container can be reduced, and the size of the vacuum container can be reduced. Note that, in this specification, an atom includes an ionized atom.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. In the description of this embodiment, the same reference numerals are given to the same parts as those in the conventional example, and the overlapping description of the common parts will be omitted.

In this embodiment, a vacuum container 1 for accommodating and sealing the vibrating body 7 (sensor section 8) as shown in FIG. 4 will be described as an example, and an example of a manufacturing process of the vacuum container 1 will be described. What is characteristic in this embodiment is that, after bonding the base 2 and the semiconductor substrate 3, a process for removing nonmetal atoms such as oxygen atoms from the surface of the semiconductor substrate 3 is performed, and the semiconductor exposed by the process is removed. After bonding copper atoms to the surface of the substrate 3, the lid member 4 is anodically bonded to the upper side of the semiconductor substrate 3 to which the copper atoms have been bonded. The other configuration is almost the same as the manufacturing process of the vacuum container shown in the conventional example.

That is, in this embodiment, first, as shown in FIG. 1A, a concave portion 2a is formed in the base 2 by using sandblasting, and then, as shown in FIG. Then, the semiconductor substrate 3 is anodically bonded to the upper side of the base 2. Then, as shown in FIG. 1C, the semiconductor substrate 3 is thinned to a predetermined thickness by, for example, surface grinding, and the surface of the thinned semiconductor substrate 3 is mirror-polished. Thereafter, as shown in FIG. 1D, the semiconductor substrate 3 is processed into a pattern shape as shown in FIG. 4 by using a technique such as etching or photolithography.

After that, the base 2 and the semiconductor are added to a cleaning liquid (for example, an aqueous solution in which 3 wt% of hydrogen peroxide and 3 wt% of ammonia are mixed) heated to a set temperature (for example, about 80 ° C.). The bonded body of the substrate 3 is immersed for a set time (for example, 10 minutes). Next, the joined body is removed from the cleaning liquid, and rinsed with running water for a set time (for example, about 5 minutes).

After the running water rinse, a mixed aqueous solution of hydrogen fluoride and copper chloride (for example, 1 wt% of hydrogen fluoride,
The above joined body is immersed in a mixed aqueous solution containing 0.3 ppm of copper chloride) for a set time (for example, 10 minutes).

Incidentally, for example, silicon atoms on the surface of the semiconductor substrate 3 are very easily bonded to oxygen atoms, which are nonmetallic atoms. I do. Thus, an oxide layer 3a is formed on the semiconductor substrate 3 as shown in FIG. Since the hydrogen fluoride is a substance capable of removing non-metal atoms such as the oxygen atoms from the upper surface of the semiconductor substrate 3, as described above, the joined body of the base 2 and the semiconductor substrate 3 is formed. By immersing in the mixed aqueous solution of hydrogen fluoride and copper chloride, oxygen atoms naturally bonded to the surface of the semiconductor substrate 3 are removed from the surface of the semiconductor substrate 3 and the surface of the semiconductor substrate 3 is exposed.

Before immersing the bonded body in the mixed aqueous solution of hydrogen fluoride and copper chloride, the surface of the semiconductor substrate 3 contains not only the above-mentioned oxygen atoms but also a small amount other than the oxygen atoms. Non-metal atoms such as hydrogen atoms are also bonded, but in the mixed aqueous solution, the non-metal atoms such as hydrogen atoms are also removed from the surface of the semiconductor substrate 3 in the same manner as the oxygen atoms.

The copper atoms, which are metal atoms in the mixed aqueous solution, have a stronger bond with the surface of the semiconductor substrate 3 than the bond between the surface of the semiconductor substrate 3 and the non-metal atoms such as oxygen atoms. As described above, by immersing the joined body of the base 2 and the semiconductor substrate 3 in the mixed aqueous solution of hydrogen fluoride and copper chloride, the copper atoms in the mixed aqueous solution are exposed to the surface of the exposed semiconductor substrate 3. Then, as shown in FIG. 1F, a copper-containing layer 20 is formed on the semiconductor substrate 3.

In this embodiment, as described above, a process of exposing the surface of the semiconductor substrate 3 by removing the non-metallic atoms such as the oxygen atoms from the surface of the semiconductor substrate 3, The process of bonding copper atoms to the surface is performed in the same step.

Thereafter, the joined body is taken out of the mixed aqueous solution and rinsed with running water for a set time (for example, about 5 minutes), and the joined body is dried using, for example, a spin drier.

Thereafter, the lid member 4 is anodically bonded to the upper side of the semiconductor substrate 3 to which the copper atoms have been bonded in a vacuum chamber in which evacuation is performed. FIG.
As shown in (g), a concave portion 4a is formed by sandblasting, and a through hole 18 is formed.
As in the conventional example, the semiconductor substrate 3 is positioned as described above with the recess 4a and the through hole 18 aligned.
And the lid member 4 are anodically bonded. Thus, the vacuum container 1 can be manufactured.

According to this embodiment, after the base 2 and the semiconductor substrate 3 are joined, non-metal atoms such as oxygen atoms bonded to the surface of the semiconductor substrate 3 are removed to remove the surface of the semiconductor substrate 3. Is exposed, and in this state, copper atoms which are metal atoms are bonded to the exposed surface of the semiconductor substrate 3, and then the lid member 4 is anodically bonded to the upper side of the semiconductor substrate 3. Thereby, the base 2, the semiconductor substrate 3, and the lid member 4 are formed.
The degree of vacuum in the vacuum space 6 in the vacuum vessel 1 can be made better than in the past. This has been confirmed by experiments performed by the present inventors.

The experiment means that a plurality of vacuum containers 1 are manufactured by the manufacturing process shown in the above embodiment, and a plurality of vacuum containers 1 are manufactured by the conventional manufacturing process. The degree of vacuum in the vacuum space 6 was examined, and each vacuum vessel 1 was classified based on the degree of vacuum in the vacuum space 6. FIG. 2A shows the distribution of the degree of vacuum in the vacuum vessel 1 when the plurality of vacuum vessels 1 manufactured in the manufacturing process shown in the above embodiment are classified based on the degree of vacuum in the vacuum space 6. FIG. 2 (b) shows a plurality of vacuum containers 1 manufactured by a conventional manufacturing process in a vacuum space 6 in the same manner as described above.
3 shows the state of distribution of the degree of vacuum of the vacuum vessel 1 when the classification is performed based on the degree of vacuum.

FIG. 2 shows a conventional manufacturing process.
As shown in (b), the degree of vacuum in the vacuum space 6 of each vacuum vessel 1 varies, and in this experimental result,
In about 40% of the plurality of vacuum vessels 1 manufactured by the conventional manufacturing process, the degree of vacuum of the vacuum space 6 is 64%.
It was 0 Pa or more. On the other hand, when manufactured in the manufacturing process of the above-described embodiment, as shown in FIG. 2A, the variation in the degree of vacuum in the vacuum space 6 of each vacuum vessel 1 is suppressed to be small. In all the vacuum vessels 1 manufactured in the embodiment, the degree of vacuum in the vacuum space 6 is 320 Pa or less, and the degree of vacuum in the vacuum space 6 is much higher than that in the conventional manufacturing process. It can be seen that it has improved.

As is clear from the above experimental results, the vacuum vessel 1 is manufactured by the manufacturing process shown in this embodiment.
By making the above, the degree of vacuum in the vacuum space 6 of the vacuum container 1 can be made much better than in the past.

The present inventor believes that good results can be obtained by the manufacturing process shown in this embodiment for the following reasons. For example, when the semiconductor substrate 3 and the cover member 4 are anodic-bonded, unnecessary gas generated from the anodic bonding portion between the semiconductor substrate 3 and the cover member 4 may include oxygen atoms naturally bonded to the surface of the semiconductor substrate 3 or It is speculated that the gas may be non-metallic atoms such as hydrogen atoms. In this embodiment, as described above,
Non-metallic atoms such as oxygen atoms and hydrogen atoms are removed from the surface of the semiconductor substrate 3 to expose the surface of the semiconductor substrate 3, and copper atoms are bonded to the exposed surface of the semiconductor substrate 3.
As described above, the degree of bonding between the copper atoms and the surface of the semiconductor substrate 3 is stronger than the degree of bonding between the surface of the semiconductor substrate 3 and the nonmetallic atoms. For this reason, by bonding copper atoms to the surface of the semiconductor substrate 3 as described above, a state where non-metal atoms such as oxygen atoms and hydrogen atoms cannot be bonded to the surface of the semiconductor substrate 3 can be obtained.

In the state where the non-metallic atoms are not bonded to the surface of the semiconductor substrate 3 due to the copper atoms on the surface of the semiconductor substrate 3, in other words, the anode of the semiconductor substrate 3 and the anode of the lid member 4. Since the anodic bonding of the semiconductor substrate 3 and the cover member 4 is performed in a state where the constituent atoms of the unnecessary gas generated at the time of bonding are not bonded to the surface of the semiconductor substrate 3, the generation of the unnecessary gas is suppressed. The vacuum space 6
The present inventor thinks that the degree of vacuum can be improved.

As described above, by manufacturing the vacuum vessel 1 in the manufacturing process shown in this embodiment, it is possible to make the vacuum state of the vacuum space 6 a good state as confirmed by the above experimental results. It becomes possible. From this, FIG.
When the vibrating body 7 of the angular velocity sensor is accommodated in the vacuum space 6, the vibration state of the vibrating body 7 of each vacuum vessel 1 becomes almost the same, and the sensitivity variation of the angular velocity sensor is suppressed very small. Therefore, the reliability of the performance of the angular velocity sensor can be improved.

In this embodiment, the vacuum state of the vacuum space 6 can be improved without disposing the gas adsorbing substance inside the vacuum space 6 of the vacuum vessel 1. The labor for installing the gas adsorbing substance is not required, and the vacuum space 6 can be reduced because the gas adsorbing substance does not need to be provided, which facilitates downsizing of the vacuum vessel 1.

Further, in this embodiment, the process of exposing the surface of the semiconductor substrate 3 by removing nonmetallic atoms such as oxygen atoms from the surface of the semiconductor substrate 3, Is performed in the same step, so that the manufacturing process can be simplified as compared with the case where each of the above-described steps is performed in a separate step.

Further, in this embodiment, since the concave portions 2a, 4a of the base 2 and the cover member 4 are formed by sandblasting, the following effects can be obtained. For example, since the front and back surfaces of the vibrating body 7 are very smooth surfaces, if the bottom surfaces of the recesses 2a and 4a of the base 2 and the cover member 4 are also smooth surfaces, the vacuum vessel 1 When the vibrating member 7 comes into contact with the bottom surface of the concave portion 2a or the concave portion 4a due to a cause such as dropping, the vibrating member 7 comes into close contact with the bottom surface of the concave portion 2a or the concave portion 4a, and the vibrating member 7 can move. And the angular velocity sensor stops functioning, for example.

Further, if the bottom surfaces of the concave portions 2a and 4a are smooth surfaces, there is a possibility that the above-mentioned problem of close contact of the vibrating body 7 may occur during the manufacturing process. For example, FIG.
As shown in (1), after the semiconductor substrate 3 is processed to form the vibrating body 7 in a floating state, the joined body of the base 2 and the semiconductor substrate 3 is washed and dried. In the washing step, liquid enters the gap between the vibrating body 7 and the bottom surface of the concave portion 2a. In the next drying step, as the liquid evaporates by drying, the vibrating body is caused by the surface tension of the liquid. When the liquid is completely evaporated and the drying is completed, the vibrating body 7 may be in a state of being in close contact with the bottom surface of the concave portion 2a. As a result, the vibrating body 7 cannot move.

On the other hand, in this embodiment, since the recesses 2a and 4a are formed by sandblasting as described above, the bottom surface of each of the recesses 2a and 4a has a roughness R of 0. It has a rough surface of 3 μm or more.
From this, it is possible to prevent the vibrating body 7 from being in close contact with the bottom surfaces of the concave portions 2a and 4a, and
Adhesion between the bottom surfaces of the recesses 2a and 4a and the vibrating body 7 as described above can be reliably prevented.

Note that the present invention is not limited to the above-described embodiment, but can adopt various embodiments. For example, in the above embodiment, the base 2 and the lid member 4 are glass substrates, but any material other than a glass substrate may be used as long as the base 2 and the lid member 4 can be anodic-bonded to the semiconductor substrate 3. The lid member 4 may be configured. In addition, the semiconductor substrate 3
May be constituted by a semiconductor other than silicon.

Further, in the above embodiment, after the surface of the semiconductor substrate 3 is exposed by removing non-metallic atoms such as oxygen atoms from the surface of the semiconductor substrate 3, the semiconductor substrate 3 is bonded to the exposed surface of the semiconductor substrate 3. Although a copper atom is shown as a metal atom, the metal atom may be any one as long as the degree of bonding with the surface of the semiconductor substrate 3 is stronger than the degree of bonding with the surface of the semiconductor substrate 3 and the nonmetallic atom. It is not limited to copper atoms.

Further, in the above embodiment, hydrogen fluoride was used as a removing substance for removing nonmetal atoms such as oxygen atoms from the surface of the semiconductor substrate 3, but the removing substance may be a material other than hydrogen fluoride. Good.

Further, in the above embodiment, the processing for removing the non-metallic atoms from the surface of the semiconductor substrate 3 and the processing for bonding the metal atoms to the surface of the semiconductor substrate 3 exposed by the processing are performed in the same step. However, these treatments may be performed in separate steps. When the process of removing the non-metallic atoms from the surface of the semiconductor substrate 3 and the process of bonding metal atoms to the surface of the semiconductor substrate 3 exposed by the process are performed in separate steps, When the process shifts from the process of removing non-metal atoms to the process of bonding metal atoms to the exposed surface of the semiconductor substrate 3, non-metal atoms such as oxygen atoms are bonded to the surface of the semiconductor substrate 3. Measures will be taken to prevent this from happening.

Further, in the above embodiment, the joined body of the base 2 and the semiconductor substrate 3 is immersed in a solution containing the above-mentioned substance for removal to remove non-metallic atoms from the surface of the semiconductor substrate 3. However, non-metallic atoms may be removed from the surface of the semiconductor substrate 3 by another method. In the above embodiment, the bonded body of the base 2 and the semiconductor substrate 3 is immersed in a solution containing a metal atom for bonding with a pure semiconductor atom, so that the exposed semiconductor substrate 3 Although the metal atoms are bonded to the surface, the metal atoms may be bonded to the surface of the semiconductor substrate 3 by another method.

Further, in the above embodiment, the recesses 2 are formed in the base 2 and the lid member 4 by utilizing sand blasting.
Although the recesses 2a and 4a are formed by other methods, the recesses 2a and 4a may be formed by other methods. Further, in the above-described embodiment, the example in which the vibrating body 7 (the sensor unit 8) as shown in FIG. 4 is housed inside the vacuum space 6 of the vacuum vessel 1 has been described. What is performed is not limited to the vibrator 7. Further, in the above embodiment, the vacuum space 6 is formed by forming the recesses 2a and 4a in the base 2 and the lid member 4 respectively. However, for example, one or both of the base 2 and the lid member 4 are formed. By forming the semiconductor substrate 3, for example, by making the central region thinner than the edge region without forming the concave portion, a gap is formed between the base 2 and the lid member 4 and the semiconductor substrate 3 to form the vacuum space 6. May be formed.

In the above embodiment, the semiconductor substrate 3
The description has been given by taking as an example the case where the nonmetal atom mainly bonded to the surface of the semiconductor substrate 3 is an oxygen atom. In the same manner as described above, the non-metal atoms such as hydrogen atoms are removed to expose the surface of the semiconductor substrate 3, and the metal surface such as copper atoms is exposed on the exposed surface of the semiconductor substrate 3. Then, the lid member 4 is bonded to the upper side of the semiconductor substrate 3 to which the metal atom has been bonded, whereby the same excellent effects as in the above embodiment can be obtained.

[0058]

According to the present invention, after joining a semiconductor substrate to the upper side of a base, nonmetallic atoms bonded to the surface of the semiconductor substrate are removed to expose the surface of the semiconductor substrate. Then, a metal atom having a higher degree of bonding with the surface of the semiconductor substrate than the degree of bonding between the surface of the semiconductor substrate and the non-metallic atom is bonded to the exposed surface of the semiconductor substrate. Since the lid member is anodic-bonded to the upper side of the semiconductor substrate to which the metal atoms are bonded, generation of unnecessary gas during the anodic bonding can be suppressed, and the vacuum space of the vacuum vessel is reduced in vacuum degree. It can be sealed in a state. Further, it is possible to suppress a variation in the degree of vacuum in the vacuum space of the vacuum container.

In the invention in which the metal atom is a copper atom, the copper atom has a high degree of bonding to the surface of the semiconductor substrate, and therefore can be bonded to the surface of the semiconductor substrate very stably. Generation of unnecessary gas during anodic bonding between the semiconductor substrate and the lid member can be more reliably suppressed.

In the invention in which the process of removing non-metal atoms from the surface of the semiconductor substrate and the process of bonding metal atoms to the surface of the semiconductor substrate exposed by the process are performed in the same step, the above-described processes are separately performed. The manufacturing process can be simplified as compared with the case of performing the above process.

In the invention in which the removing substance for removing nonmetal atoms from the surface of the semiconductor substrate is hydrogen fluoride, hydrogen fluoride is an easily available material and is inexpensive. The increase can be suppressed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a method for manufacturing a vacuum vessel according to the present invention.

FIG. 2 is a graph showing the results of an experiment performed by the present inventors.

FIG. 3 is a model diagram for explaining a vacuum container.

FIG. 4 is an explanatory view showing an example of a vibrating body accommodated in a vacuum container.

FIG. 5 is an explanatory view showing an example of a manufacturing process of a conventional vacuum vessel.

[Explanation of symbols]

 Reference Signs List 1 vacuum container 2 base 3 semiconductor substrate 4 lid member 6 vacuum space 20 copper-containing layer

Claims (4)

[Claims] 1. A method of manufacturing a vacuum vessel in which a semiconductor substrate is bonded to an upper side of a base and a vacuum space is formed inside a laminate formed by anodically bonding a lid member to the upper side of the semiconductor substrate. After bonding the semiconductor substrate to the upper side of the base, non-metal atoms bonded to the surface of the semiconductor substrate are removed to expose the surface of the semiconductor substrate, and in this state, the semiconductor substrate is exposed. Bonding a metal atom having a higher bonding degree between the surface and the surface of the semiconductor substrate than the bonding degree between the surface and the non-metallic atom to the exposed surface of the semiconductor substrate,
Thereafter, a lid member is anodically bonded to the upper surface of the semiconductor substrate to which the metal atoms are bonded, the method for manufacturing a vacuum container. 2. The method according to claim 1, wherein the metal atom is a copper atom. 3. The method according to claim 1, further comprising: removing the non-metallic atoms bonded to the surface of the semiconductor substrate from the base material; The same process of immersing the bonded body of the semiconductor substrate and removing the non-metallic atoms from the surface of the semiconductor substrate with the removing substance and bonding the metal atoms to the surface of the semiconductor substrate exposed by the processing is performed in the same step. The method for producing a vacuum vessel according to claim 1, wherein the method is performed. 4. The method according to claim 3, wherein the removing substance is hydrogen fluoride.