JP2003270262A - Semiconductor acceleration sensor and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor acceleration sensor proper for small-sizing and to provide its production method. <P>SOLUTION: The semiconductor acceleration sensor comprises an acceleration sensor chip 4 constituted by having a frame 1 and a plummet 2, and hanging the plummet 2 to the frame 1 consisting of a semiconductor substrate, and at least a slab shape glass stopper facing to the plummet 2 in a state with a gap and connected and supported to the frame 1 by using anode junction. At least one side of the facing surface between the plummet 2 and the glass stopper, a contact prevention part 8 (8a, 8b) preventing the contact of the two is provided. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor acceleration sensor used in, for example, automobiles, airplanes and home electric appliances.

[0002]

2. Description of the Related Art As a conventional semiconductor acceleration sensor, for example, a so-called double-supported type shown in FIG.
A so-called cantilever system shown in FIG. 9B can be mentioned.

In these semiconductor acceleration sensors, an acceleration sensor chip having a frame 1, a weight 2 and a beam 3 in which a weight 2 is suspended and supported by a beam 3 at a substantially center of a frame 1 made of silicon. 4, the weight 2 and the gaps 7a, 7
It is provided with a flat upper glass stopper 5a and a lower glass stopper 5b which are opposed to each other with b provided and are connected and supported at a desired position of the frame 1 by anodic bonding. The beam portion 3 of the acceleration sensor chip 4 has
It has a sensitive resistance element (not shown) for detecting the movement of the weight portion 2.

Here, the gaps 7a and 7b are respectively formed between the upper glass stopper 5a and the acceleration sensor chip 4 and between the lower glass stopper 5b and the acceleration sensor chip 4, for example, Al for gap formation. It is formed by inserting the spacer 6 which becomes. These gaps 7a and 7b prevent the weight portion 2 which is a movable portion from colliding with the upper glass stopper 5a and the lower glass stopper 5b.

The anodic bonding means, for example, the frame 1 of the acceleration sensor chip 4 is brought into contact with the main surface of the upper glass stopper 5a, and the cathode conductor plate (not shown) is attached to the other main surface of the upper glass stopper 5a. Contact each other and apply a DC voltage with the frame 1 as the anode and the cathode conductor plate as the cathode, and at the same time 3
It is a method of heating at a heating temperature of about 50 to 500 ° C. and connecting a desired portion of the frame 1 and the upper glass stopper 5a.

[0006]

However, in the semiconductor acceleration sensor as described above, a DC voltage is applied when the upper glass stopper and the lower glass stopper are anodically bonded to the frame of the acceleration sensor chip made of silicon. An electric field is generated in the frame, but at this time, an electric field is also generated in the weight portion connected to the frame.

At this time, since the silicon ions in the weight portion move toward the upper glass stopper and the lower glass stopper due to the electric field generated in the weight portion, the weight portion and the upper glass stopper,
If the amount of the gap provided between the lower glass stopper and the lower glass stopper is small, there is a problem that the weight portion is bonded to the upper glass stopper and the lower glass stopper.

Therefore, in order to solve this problem, a gap amount with a sufficient margin has been conventionally designed in advance, but in this case, the semiconductor acceleration sensor becomes large in the height direction, and the semiconductor acceleration sensor becomes large. There is a problem that miniaturization of the acceleration sensor is hindered.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a semiconductor acceleration sensor suitable for miniaturization and a manufacturing method thereof.

[0010]

According to another aspect of the semiconductor acceleration sensor of the present invention, a gap is formed between an acceleration sensor chip 4 formed by suspending and supporting a weight portion 2 on a frame 1 made of a semiconductor substrate and the weight portion 2. Semiconductor acceleration including at least one flat glass stopper (upper glass stopper 5a, lower glass stopper 5b), which are opposed to each other with 7a and 7b provided and are connected and supported to the frame 1 by anodic bonding. In the sensor, an adhesion prevention part 8 (8a, 8a, 8a, 8a, 8a, 8a) for preventing the weight 2 and the glass stopper (upper glass stopper 5a, lower glass stopper 5b) facing each other from being adhered to at least one of the surfaces.
b) is provided.

A semiconductor acceleration sensor according to a second aspect of the present invention is the semiconductor acceleration sensor according to the first aspect of the present invention, wherein the glass stoppers (upper glass stopper 5a, lower glass stopper 5) are used.
At least the surface facing the weight portion 2 in b) is characterized in that a roughened portion 8a having a roughened surface is provided as the adhesion preventing portion 8.

The semiconductor acceleration sensor according to claim 3 is the semiconductor acceleration sensor according to claim 1 or 2, wherein at least the glass stoppers (upper glass stopper 5a, lower glass stopper 5b) of the weight 2 are provided. An insulating film 8b having heat resistance to the heating temperature at the time of anodic bonding is provided as the adhesion preventing portion 8 on the opposing surface.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a semiconductor acceleration sensor, wherein at least one flat plate-like shape is provided for an acceleration sensor chip 4 in which a weight portion 2 is suspended and supported by a frame 1 made of a semiconductor substrate. The glass stoppers (upper glass stopper 5a, lower glass stopper 5b) are opposed to each other with the weights provided with gaps 7a, 7b, and the frame 1 and the glass stopper (upper glass stopper 5a, In the method of manufacturing a semiconductor acceleration sensor for connecting and supporting a lower glass stopper 5b), the both are bonded to at least one of the facing surfaces of the weight portion 2 and the glass stopper (the upper glass stopper 5a, the lower glass stopper 5b). After performing an adhesion prevention treatment to prevent the above, the frame 1 and the glass stopper (upper Glass stopper 5a, and a lower glass stopper 5b) is characterized in that the anodic bonding.

Further, in the method of manufacturing a semiconductor acceleration sensor according to a fifth aspect, in the invention according to the fourth aspect, at least the weight portion 2 of the glass stopper (the upper glass stopper 5a and the lower glass stopper 5b) is formed. The opposite surface is provided with a roughened portion 8a to perform the adhesion prevention treatment.

The method of manufacturing a semiconductor acceleration sensor according to claim 6 is the method according to claim 4 or 5, wherein at least the glass stopper (upper glass stopper 5a, lower glass stopper) of the weight portion 2 is used. 5b)
The adhesion preventing treatment is performed by providing an insulating film 8b having heat resistance against the heating temperature at the time of anodic bonding on the surface facing to.

[0016]

DETAILED DESCRIPTION OF THE INVENTION A first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a sectional view showing a semiconductor acceleration sensor according to the first embodiment of the present invention. The first embodiment is an embodiment in which the adhesion preventing portion 8 is provided on the upper glass stopper 5a and the lower glass stopper 5b sides.

In the first embodiment, as shown in FIG. 1, the semiconductor acceleration sensor is of a double-supported type, in which a weight portion 2 is suspended and supported by a beam portion 3 at approximately the center of a frame 1 made of silicon. 1, the acceleration sensor chip 4 having the weight part 2, the weight part 2 and the beam part 3, and the weight part 2 have gaps 7a, 7a.
The upper glass stopper 5a and the lower glass stopper 5b are formed in a flat plate shape and are opposed to each other with b provided and are connected and supported at a desired position of the frame 1 by anodic bonding. The beam portion 3 supporting the weight portion 2 of the acceleration sensor chip 4 has a sensitive resistance element (not shown) for detecting the movement of the weight portion 2.

The gaps 7a and 7b are formed between the upper glass stopper 5a and the acceleration sensor chip 4, respectively.
A spacer 6 for forming a gap is provided between the lower glass stopper 5b and the acceleration sensor chip 4, for example, to prevent the weight portion 2 from being adhered to the upper glass stopper 5a and the lower glass stopper 5b.

Al is generally used for the spacer 6, but
Any metal such as Ni or Mo that can be joined to the upper glass stopper 5a and the lower glass stopper 5b may be used.

Here, the semiconductor acceleration sensor is provided with respect to the upper glass stopper 5a and the lower glass stopper 5b.
A roughened portion 8a having a roughened surface is provided as an adhesion prevention portion 8 on the surface facing the weight portion 2.

The method of manufacturing the semiconductor acceleration sensor will be briefly described below. First, wet etching with HF solution, sandblasting, and RIE (Reacti)
by subjecting the regions of the upper glass stopper 5a and the lower glass stopper 5b facing the weight portion 2 to a surface roughening treatment which is an adhesion preventing treatment by a dry etching treatment such as veIon Etching). To provide. Next, as shown in FIG. 1, the upper glass stopper 5a and the lower glass stopper 5b are connected and supported by the frame 1 by anodic bonding so that each roughened portion 8a faces the weight portion 2. The surface roughening process is terminated when the surface roughening portion 8a has a desired surface roughness.

In the anodic bonding, for example, a desired DC voltage that does not cause dielectric breakdown is applied to each part constituting the acceleration sensor chip 4 and at the same time, heating is performed at about 400 ° C., for example.

In the semiconductor acceleration sensor and the manufacturing method thereof, by providing the roughened portion 8a in the regions of the upper glass stopper 5a and the lower glass stopper 5b facing the weight portion 2, the weight portion 2 and the upper glass stopper 5a are provided. Since the contact area with the lower glass stopper 5b and the lower glass stopper 5b can be reduced, the upper glass stopper 5a can be formed by anodic bonding.
When the lower glass stopper 5b and the lower glass stopper 5b are connected and supported by the frame 1, the weight 2 can be prevented from adhering to the upper glass stopper 5a and the lower glass stopper 5b.

For this reason, the weight portion 2 has the upper glass stopper 5
Since the gaps 7a and 7b can be formed in accordance with design conditions that are determined by the characteristic surface of the weight portion 2 such as the acceleration when touching a or the lower glass stopper 5b and the resonance frequency of the weight portion 2, etc. in the height direction. It is not necessary to provide a large gap in advance, and a semiconductor acceleration sensor suitable for miniaturization can be provided.

That is, in the spacer 6 shown in FIG. 1, the adhesion preventing portion 8 is provided as described above, so that the spacer 6 shown in FIG.
It is possible to use a spacer having a height lower than the height of the spacer 6 at each corresponding position shown in (a).

Further, by providing the roughened portion 8a as described above, even when the weight portion 2 is displaced (swings) to contact the upper glass stopper 5a and the lower glass stopper 5b,
It is possible to prevent the weight 2 from being adhered to the upper glass stopper 5a and the lower glass stopper 5b.

Next, an embodiment in which the adhesion preventing portion 8 is provided on the acceleration sensor chip 4 side will be described as a second embodiment of the present invention with reference to FIG. FIG. 2 is a sectional view showing a semiconductor acceleration sensor according to the second embodiment of the present invention. The same parts as those in the first embodiment are designated by the same reference numerals,
Description of common parts is omitted.

The second embodiment differs from the first embodiment in that, as shown in FIG. 2, the upper glass stopper 5a.
And the lower glass stopper 5b is not provided with the adhesion preventing portion 8,
The insulating film 8b is provided as the adhesion preventing portion 8 on the lower surface of the weight 2 and the upper surface of the acceleration sensor chip 4 so as to include at least the upper surface of the weight 2.

Here, on the upper surface side of the acceleration sensor chip 4 including the lower surface portion of the weight portion 2 and the beam portion 3 and the upper surface portion of the weight portion 2, an insulating film 8b is provided as an adhesion preventing portion 8. The insulating film 8b may be, for example, an oxide film or a nitride film, but is not limited to these as long as it has heat resistance to a desired heating temperature applied at the time of anodic bonding and has insulating performance. Not a thing.

The method of manufacturing the semiconductor acceleration sensor will be briefly described below. First, the insulating film 8b as described above is provided on the lower surface portion of the weight portion 2 and the upper surface side of the acceleration sensor chip 4 including the beam portion 3 and the upper surface portion of the weight portion 2 to perform the adhesion prevention processing. . Next, as shown in FIG. 2, the upper glass stopper 5a and the lower glass stopper 5b are connected and supported by the frame 1 by anodic bonding. The insulating film 8
The adhesion prevention process of providing b is finished when the insulating film 8b has a desired thickness.

In the semiconductor acceleration sensor and the method of manufacturing the same, the insulating film 8b is provided on at least the upper surface portion and the lower surface portion of the weight portion 2, so that the upper glass stopper 5a and the lower glass portion 5a and the lower glass are attached to the frame 1 by anodic bonding. When the stopper 5b is connected and supported, the influence of the movement of ions due to the electric field generated in the weight portion 2 can be removed, so that the weight portion 2 can be prevented from adhering to the upper glass stopper 5a and the lower glass stopper 5b. it can.

Therefore, as in the first embodiment, the weight portion 2
Gap 7 according to the design conditions determined from the characteristics of
Since a and 7b can be formed, it is not necessary to previously provide a large gap in the height direction, and a semiconductor acceleration sensor suitable for miniaturization can be provided.

That is, in the spacer 6 shown in FIG. 2, the adhesion preventing portion 8 is provided as described above so that the spacer 6 shown in FIG.
It is possible to use a spacer having a height lower than the height of the spacer 6 at each corresponding position shown in (a).

Further, by providing the insulating film 8b as described above, even when the weight portion 2 touches the upper glass stopper 5a and the lower glass stopper 5b due to displacement (swing), the weight portion 2 and the upper glass stopper 5b. It is possible to prevent the adhesion between 5a and the lower glass stopper 5b.

Next, an embodiment in which the adhesion preventing portion 8 is provided on the acceleration sensor chip 4 side and the upper glass stopper 5a will be described.
A third embodiment of the present invention will be described with reference to FIG.
FIG. 3 is a sectional view showing a semiconductor acceleration sensor according to the third embodiment of the present invention. The same parts as those in the first and second embodiments are designated by the same reference numerals, and the description of common parts will be omitted.

In the third embodiment, as shown in FIG. 3, in the semiconductor acceleration sensor, an insulating film 8b is provided as an adhesion preventing portion 8 on the lower surface of the weight portion 2 and the weight portion 2 of the upper glass stopper 5a is provided. A roughened portion 8a is provided as an adhesion preventing portion 8 in the opposing area.

The method of manufacturing the semiconductor acceleration sensor will be briefly described below. Similar to the second embodiment, the adhesion preventing process is performed by previously providing the insulating film 8b on the lower surface portion of the weight portion 2. Further, similarly to the first embodiment, the region facing the weight portion 2 of the upper glass stopper 5a is subjected to a roughening treatment as an adhesion preventing treatment to provide a roughening portion 8a. Then, as shown in FIG. 3, the frame 1 is formed using anodic bonding.
Upper glass stopper 5a and lower glass stopper 5b
To support.

In the semiconductor acceleration sensor and the manufacturing method thereof, the insulating film 8b is provided on the lower surface of the weight portion 2, and the roughened portion 8a is provided in the region of the upper glass stopper 5a on the side facing the weight portion 2. By providing the above, when the upper glass stopper 5a and the lower glass stopper 5b are connected and supported by the frame 1 by anodic bonding, it is possible to prevent the weight portion 2 from being adhered to the upper glass stopper 5a and the lower glass stopper 5b. it can.

For this reason, similarly to the first and second embodiments, the weight portion 2 such as the acceleration when the weight portion 2 touches the upper glass stopper 5a and the lower glass stopper 5b, the resonance frequency of the weight portion 2 and the like. Since the gaps 7a and 7b can be formed in accordance with the design condition determined from the characteristic aspect of (1), it is not necessary to previously provide a large gap in the height direction, and a semiconductor acceleration sensor suitable for miniaturization can be provided. it can.

Further, by providing the roughened portion 8a and the insulating film 8b respectively as described above, even when the weight portion 2 is displaced (swings) to touch the upper glass stopper 5a and the lower glass stopper 5b, It is possible to prevent the weight 2 from being adhered to the upper glass stopper 5a and the lower glass stopper 5b.

Next, an embodiment in which the adhesion preventing portion 8 is provided on the acceleration sensor chip 4 side and the lower glass stopper 5b will be described.
A fourth embodiment of the present invention will be described with reference to FIG.
FIG. 4 is a sectional view showing a semiconductor acceleration sensor according to the fourth embodiment of the present invention. The same parts as those in the first and second embodiments are designated by the same reference numerals, and the description of common parts will be omitted.

In the fourth embodiment, the semiconductor acceleration sensor has the insulating film 8b as the adhesion preventing portion 8 on the upper surface side of the acceleration sensor chip 4 including the beam 3 and the upper surface of the weight 2.
And a roughened portion 8a is provided as an adhesion preventing portion 8 in a region of the lower glass stopper 5b facing the weight portion 2.

The method of manufacturing the semiconductor acceleration sensor will be briefly described below. Similar to the first embodiment, the surface of the lower glass stopper 5b facing the weight 2 is subjected to a surface roughening treatment, which is an adhesion preventing treatment, to provide the roughening portion 8a. Further, similarly to the second embodiment, the adhesion preventing process is performed by providing the insulating film 8b on the upper surface side of the acceleration sensor chip 4 including the upper surfaces of the beam portion 3 and the weight portion 2. Then, as shown in FIG. 4, the upper glass stopper 5a and the lower glass stopper 5b are formed on the frame 1 by anodic bonding.
To support.

In the semiconductor acceleration sensor and the manufacturing method thereof, the insulating film 8b is provided so as to include at least the upper surface portion of the weight portion 2, and the lower glass stopper 5b is provided.
By providing the roughened portion 8a in the region on the side opposite to the weight portion 2, the weight portion 2 and the upper portion when the upper glass stopper 5a and the lower glass stopper 5b are connected and supported by the frame 1 by anodic bonding. Adhesion between the glass stopper 5a and the lower glass stopper 5b can be prevented.

Therefore, similarly to the first and second embodiments, the weight portion 2 such as the acceleration when the weight portion 2 touches the upper glass stopper 5a and the lower glass stopper 5b, the resonance frequency of the weight portion 2, and the like. Since the gaps 7a and 7b can be formed in accordance with the design condition determined from the characteristic aspect of (1), it is not necessary to previously provide a large gap in the height direction, and a semiconductor acceleration sensor suitable for miniaturization can be provided. it can.

Further, by providing the roughened portion 8a and the insulating film 8b respectively as described above, even when the weight portion 2 is displaced (swings) to contact the upper glass stopper 5a and the lower glass stopper 5b, It is possible to prevent the weight 2 from being adhered to the upper glass stopper 5a and the lower glass stopper 5b.

Next, an embodiment in which the adhesion preventing portion 8 is provided on the acceleration sensor chip 4 side and the upper glass stopper 5a and the lower glass stopper 5b will be described as a fifth embodiment of the present invention with reference to FIGS. To do. 5 and 6 show
It is sectional drawing which shows the semiconductor acceleration sensor which concerns on 5th Embodiment of this invention, FIG. 5 is a both-ends type semiconductor acceleration sensor, and FIG. 6 shows a cantilever type semiconductor acceleration sensor.

First, in the fifth embodiment, as shown in FIG. 5, the semiconductor acceleration sensor is a double-sided type,
Roughening portions 8a are provided as adhesion preventing portions 8 in regions of the upper glass stopper 5a and the lower glass stopper 5b that face the weight portion 2. Further, an insulating film 8b is provided as an adhesion preventing portion 8 on the upper surface side of the acceleration sensor chip 4 including the lower surface portion of the weight portion 2 and the beam portion 3 and the upper surface portion of the weight portion 2.

Here, in the semiconductor acceleration sensor of the cantilever system, as shown in FIG. 6, a weight portion 2 is suspended and supported by a beam portion 3 at approximately the center of a frame 1 made of silicon.
The acceleration sensor chip 4 having the frame 1, the weight portion 2 and the beam portion 3 and the weight portion 2 face each other with the gaps 7a and 7b provided, and a desired position of the frame 1 is obtained by anodic bonding. It comprises a flat plate-shaped upper glass stopper 5a and a lower glass stopper 5b which are connected to and supported by. Note that, similarly to the double-support type, the beam portion 3 supporting the weight portion 2 of the acceleration sensor chip has a sensitive resistance element (not shown) that detects the movement of the weight portion 2.

Also in the cantilever type semiconductor acceleration sensor, as in the case of the both-end type shown in FIG. 5, the adhesion preventing portion 8 is provided in the regions of the upper glass stopper 5a and the lower glass stopper 5b facing the weight portion 2. The roughened portion 8a is provided, and the insulating film 8b is provided as the adhesion preventing portion 8 on the lower surface portion of the weight portion 2 and the upper surface portion of the weight portion 2.

The method of manufacturing the semiconductor acceleration sensor is a combination of the manufacturing methods of the first to fourth embodiments, and therefore the description thereof is omitted.

In the semiconductor acceleration sensor and the method of manufacturing the same, the insulating film 8b is provided so as to include at least the upper surface portion and the lower surface portion of the weight portion 2 and faces the weight portions 2 of the upper glass stopper 5a and the lower glass stopper 5b. By providing the roughened portion 8a in the region on the side to be connected, when the upper glass stopper 5a and the lower glass stopper 5b are connected and supported by the frame 1 by anodic bonding, the weight portion 2, the upper glass stopper 5a and the lower glass stopper 5a are connected. Adhesion with the stopper 5b can be prevented.

In the spacer 6 shown in FIG. 5, the adhesion preventing portion 8 is provided as described above, so that the spacer 6 shown in FIG.
A height lower than the height of the spacer 6 at each corresponding position shown in (a) can be used, and the spacer 6 shown in FIG. 6 is the spacer 6 at each corresponding position shown in FIG. 9 (b) of the conventional example. Lower than the height of can be used.

For this reason, the weight portion 2 has the upper glass stopper 5
Since the gaps 7a and 7b can be formed in accordance with design conditions that are determined by the characteristic surface of the weight portion 2 such as the acceleration when touching a or the lower glass stopper 5b and the resonance frequency of the weight portion 2, etc. in the height direction. It is not necessary to provide a large gap in advance, and a semiconductor acceleration sensor suitable for miniaturization can be provided.

Further, by providing each of the roughened portion 8a and the insulating film 8b as described above, the weight portion 2 is displaced (oscillated), whereby the upper glass stopper 5a and the lower glass stopper 5b are moved.
Even when touching, it is possible to prevent the weight 2 from being adhered to the upper glass stopper 5a and the lower glass stopper 5b.

Next, an embodiment in which the upper glass stopper 5a and the lower glass stopper 5b have been subjected to counterboring in advance will be described as a sixth embodiment of the present invention with reference to FIGS. 7 and 8 are sectional views showing a semiconductor acceleration sensor according to a sixth embodiment of the present invention.
Is a dual-supported semiconductor acceleration sensor.
1 shows a cantilever type semiconductor acceleration sensor.

First, in the sixth embodiment, as shown in FIG. 7 or 8, the semiconductor acceleration sensor is provided with a countersunk portion in each of the regions of the upper glass stopper 5a and the lower glass stopper 5b facing the weight portion 2. 9a and 9b are provided, and a roughened portion 8a is further provided as an adhesion preventing portion 8 over the spot facing portions 9a and 9b. In addition, the insulating film 8 is formed as an adhesion preventing portion 8 on the upper surface portion and the lower surface portion of the weight portion 2.
b is provided.

The method of manufacturing the semiconductor acceleration sensor will be briefly described below. First, the areas of the upper glass stopper 5a and the lower glass stopper 5b facing the weight portion 2 are countersunk by a desired method to form the countersunk portion 9 in advance.
a and 9b are formed. Next, the roughened portion 8a is provided by further subjecting the spot facing portions 9a and 9b to roughening treatment which is an adhesion preventing treatment.

Further, with respect to the upper surface portion and the lower surface portion of the weight portion 2,
Adhesion prevention treatment for providing the insulating film 8b as described above is performed.
Next, as shown in FIG. 7 or 8, the upper glass stopper 5a and the lower glass stopper 5b are connected and supported on the frame 1 by anodic bonding.

In the sixth embodiment, since the countersunk portion 9b is provided on the lower glass stopper 5b, no spacer is provided between the lower glass stopper 5b and the acceleration sensor chip 4. In addition, a spacer 6 between the upper glass stopper 5a and the acceleration sensor chip 4
Uses a lower height than the spacer 6 between the upper glass stopper 5a and the acceleration sensor chip 4 of the fifth embodiment. This is because in the sixth embodiment, the upper glass stopper 5a is provided with a countersunk portion 9b.

In the semiconductor acceleration sensor and the method of manufacturing the same, the insulating film 8b is provided so as to include at least the upper surface portion and the lower surface portion of the weight portion 2 and faces the weight portions 2 of the upper glass stopper 5a and the lower glass stopper 5b. By providing the roughened portion 8a in the region on the side to be connected, when the upper glass stopper 5a and the lower glass stopper 5b are connected and supported by the frame 1 by anodic bonding, the weight portion 2, the upper glass stopper 5a and the lower glass stopper 5a are connected. Adhesion with the stopper 5b can be prevented.

Further, since the upper glass stopper 5a and the lower glass stopper 5b are provided with counterbores 9a and 9b, respectively, the height of the spacer 6 can be further reduced. Further, it is possible to provide a semiconductor acceleration sensor suitable for miniaturization.

Further, by providing the roughened portion 8a and the insulating film 8b as described above, even when the weight portion 2 is displaced (swinged) to contact the upper glass stopper 5a and the lower glass stopper 5b, the weight is reduced. It is possible to prevent the portion 2 from being adhered to the upper glass stopper 5a and the lower glass stopper 5b.

[0064]

As described above, in the semiconductor acceleration sensor of the invention according to claim 1 of the present application, the weight portion of the acceleration sensor chip in which the weight portion is suspended and supported by the frame made of the semiconductor substrate, and the acceleration When the frame and the glass stopper are connected and supported by using anodic bonding, the adhesion preventing portion is provided on at least one of the surfaces of the sensor chip facing the at least one flat plate-shaped glass stopper connected and supported by the frame. In addition, since it is possible to prevent the weight portion and the glass stopper from adhering to each other, it is possible to form a gap between the weight portion and the glass stopper in accordance with the design condition determined from the characteristic surface of the weight portion, and to adjust the height direction. It is not necessary to provide a large gap in advance, and the semiconductor acceleration sensor can be downsized.

Further, in the semiconductor acceleration sensor of the invention according to claim 2, in the invention according to claim 1, the surface of the glass stopper facing at least the weight portion is roughened as an adhesion preventing portion. By providing the roughened portion, it is possible to reduce the contact area between the weight portion and the glass stopper, so that the weight portion and the glass stopper can be prevented from adhering to each other, and a large gap in the height direction can be prevented in advance. Since it is not necessary to provide the semiconductor acceleration sensor, the semiconductor acceleration sensor can be downsized.

Further, in the semiconductor acceleration sensor of the invention according to claim 3, in the invention according to claim 1 or 2, anodic bonding is performed as an adhesion preventing portion on at least a surface of the weight portion facing the glass stopper. By providing an insulating film having heat resistance to the heating temperature at the time, when connecting and supporting the frame and the glass stopper by anodic bonding,
Since it is possible to remove the influence of ion movement caused by the electric field generated in the weight portion, it is possible to prevent the weight portion and the glass stopper from adhering to each other, and it is not necessary to preliminarily provide a large gap in the height direction. This has the effect of realizing miniaturization of the acceleration sensor.

In the method of manufacturing a semiconductor acceleration sensor according to the fourth aspect of the present invention, at least one flat plate shape is provided for the acceleration sensor chip in which a weight portion is suspended and supported by a frame made of a semiconductor substrate. The glass stopper is subjected to an adhesion preventing treatment for preventing the weight and the glass stopper from adhering to at least one of the facing surfaces of the weight and the glass stopper, and then the frame of the acceleration sensor chip and the glass stopper are attached. Since the weight and the gap are opposed to each other for anodic bonding, the weight and the glass stopper can be prevented from adhering to each other when the frame and the glass stopper are connected and supported by anodic bonding, and the size can be reduced. There is an effect that it is possible to provide a semiconductor acceleration sensor manufacturing method suitable for the above.

In the method of manufacturing a semiconductor acceleration sensor according to the fifth aspect of the invention, in the invention of the fourth aspect, it is easy to perform the roughening treatment on the flat glass stopper. Therefore, it is possible to easily provide a method of manufacturing a semiconductor acceleration sensor suitable for miniaturization.

Further, in the method of manufacturing a semiconductor acceleration sensor of the invention according to claim 6, in the invention according to claim 4 or 5, the weight portion made of a semiconductor substrate is
Since it is easy to provide an insulating film having heat resistance against the heating temperature at the time of anodic bonding, it is possible to easily provide a method for manufacturing a semiconductor acceleration sensor suitable for miniaturization.

[Brief description of drawings]

FIG. 1 is a sectional view showing a semiconductor acceleration sensor according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a semiconductor acceleration sensor according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing a semiconductor acceleration sensor according to a third embodiment of the present invention.

FIG. 4 is a sectional view showing a semiconductor acceleration sensor according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing a semiconductor acceleration sensor according to a fifth embodiment of the present invention.

FIG. 6 is a sectional view showing another semiconductor acceleration sensor according to the fifth embodiment of the present invention.

FIG. 7 is a sectional view showing a semiconductor acceleration sensor according to a sixth embodiment of the present invention.

FIG. 8 is a sectional view showing another semiconductor acceleration sensor according to the sixth embodiment of the present invention.

FIG. 9 is a sectional view showing a semiconductor acceleration sensor according to a conventional example.

[Explanation of symbols]

1 frame 2 Weight part 3 beams 4 Acceleration sensor chip 5a, 5b Glass stopper 6 spacers 7a, 7b Gap 8 Adhesion prevention part 8a Roughening section 8b insulating film 9a, 9b Search part

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Saijo             1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd.             Inside the company (72) Inventor Ryo Aoki             1048, Kadoma, Kadoma-shi, Osaka Matsushita Electric Works Co., Ltd.             Inside the company F-term (reference) 4M112 AA02 BA01 CA21 CA23 CA24                       CA36 DA03 DA04 DA05 DA18                       EA06 EA07 EA11 EA13 FA05                       FA20

Claims (6)

[Claims] 1. An acceleration sensor chip in which a weight portion is suspended and supported by a frame made of a semiconductor substrate and the weight portion face each other with a gap provided therebetween, and are connected and supported to the frame by anodic bonding. In a semiconductor acceleration sensor including at least one flat glass stopper, an adhesion preventing portion that prevents the weight and the glass stopper from adhering to each other is provided on at least one of the opposing surfaces. A semiconductor acceleration sensor characterized by the above. 2. The semiconductor acceleration sensor according to claim 1, wherein a roughened portion having a roughened surface is provided as the adhesion preventing portion on at least a surface of the glass stopper facing the weight portion. 3. The insulating film having heat resistance against a heating temperature at the time of anodic bonding is provided as the adhesion preventing portion on at least a surface of the weight portion facing the glass stopper. The semiconductor acceleration sensor according to claim 2. 4. An acceleration sensor chip in which a weight portion is suspended and supported by a frame made of a semiconductor substrate, and at least one flat glass stopper is made to face the weight portion with a gap. In a method for manufacturing a semiconductor acceleration sensor in which the frame and the glass stopper are connected and supported by using anodic bonding, it is possible to prevent the both from adhering to at least one of the facing surfaces of the weight portion and the glass stopper. A method of manufacturing a semiconductor acceleration sensor, characterized in that the frame and the glass stopper are anodically bonded after an adhesion preventing treatment. 5. The semiconductor acceleration sensor according to claim 4, wherein at least a surface of the glass stopper facing the weight portion is provided with a roughened portion having a roughened surface to perform the adhesion prevention treatment. Manufacturing method. 6. The adhesion preventing treatment is performed by providing an insulating film having heat resistance against a heating temperature at the time of anodic bonding on at least a surface of the weight portion facing the glass stopper. 4. The method for manufacturing the semiconductor acceleration sensor according to claim 4 or claim 5.