JP3402168B2 - Surface processing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface processing apparatus for processing a surface of a wafer, and more particularly to a surface processing apparatus for performing a plating process or an etching process on the surface of a wafer.

[0002]

2. Description of the Related Art Conventionally, in a chip forming region 70a of a semiconductor wafer 70 as shown in FIG. 15, a mask 71 is used as shown in FIG. 16 to form recesses 72 of about several hundred to 1000 chips in potassium hydroxide (KOH aqueous solution). Is formed by using an etching solution such as that for manufacturing a semiconductor sensor such as a pressure sensor or an acceleration sensor. When the acceleration sensor is used after FIG. 16, the through hole 76 is formed in the thin portion 75 between the thick square frame portion 73 and the weight portion 74 as shown in FIG. Thin part 75
A gauge (piezoresistive element or the like) 77 is arranged in the.

An immersion method has been generally used as an etching method. In this immersion method, for example, the masking jig shown in FIG. 18 is used. That is, the circuit surface and the edge of the wafer 70 are masked with the wax 79 on the highly corrosion-resistant plate 78 made of ceramic or the like so that only the surface to be etched is dissolved in the etching solution.

Then, as shown in FIG. 19, (i) plate 78 masked by adhering wafer 70 is arranged on carrier 80. (Ii) Carrier 80 for etching tank 8
It is immersed in the etching solution 82 in 1 to obtain a desired etching amount. (Iii) The carrier 80 is moved to a water washing tank 83 by a not-shown transporting device or the like and immersed in pure water 84 to stop the etching. (Iv) After sufficiently washing with water, the carrier 80 is taken out from the washing tank 83. (V) After the pure water used for cleaning is dried, the wax 79 of FIG. 18 is melted by a solvent cleaning device (not shown) or the like, and the wafer 70 is removed from the plate 78.

The dipping method consisting of such steps is shown in FIG.
Since the entire masking jig of No. 8 is soaked in the treatment liquid, impurities attached during the masking work may contaminate the treatment liquid, and masking materials such as wax may be eluted into the treatment liquid.
In the wafer manufacturing process that uses high-purity chemicals, it has been a problem that leads to chronic quality defects. Further, the masking work for protecting the wafer 70 is difficult to automate because it handles a fragile wafer, and the productivity is low including the solvent cleaning after etching.

In order to solve these problems, as shown in FIG. 20, a jig is used for masking the wafer 70 with a backup plate 86 and a mask ring 87 sandwiching a highly corrosion resistant rubber packing 88. However, since a fastening method such as fastening bolts or toggles that locally applies a weight is used to sandwich the wafer 70, a non-uniform weight is applied to the fragile wafer 70 during masking or removal, resulting in problems such as wafer splitting and masking failure. Yes, wax masking is still the mainstream.

In order to solve the problem of such a mechanical masking jig, the applicant of the present invention has disclosed in Japanese Unexamined Patent Publication No. 5-152278.
In the publication, as shown in FIG. 21, a wafer 70 is mounted on a base plate 89, and a vacuum chamber 90 provided on the outer peripheral portion of the base plate 89 is evacuated so that a sealing material 91 is provided on an edge portion of the wafer 70. A structure is proposed in which the ring body 92 is suction-supported and the vacuum chamber 90 uniformly masks the wafer 70.

However, this masking method is used for the wafer 7
0 and the vacuum chamber 90 of its supporting portion are evacuated to force the wafer 70 to closely contact the base plate 89 of the jig.
In recent years, there have been cases where it is not possible to cope with the increase in the diameter of wafers and the reduction in thickness of diaphragms. That is, FIG.
21. As shown in FIG. 21, since the warp of the wafer in the manufacturing process of the wafer 70 is brought into close contact with the base plate 89 by the vacuum of the vacuum chamber 90 of the masking jig shown in FIG.
Etching progresses under stress on the bottom surface of 0, and the diaphragm thickness is 10 μm or less (final thickness is 6 μm or less)
There was a problem that it would break. More specifically, since the wafer has a warp of about 200 μm, a stress is generated when the wafer is brought into close contact with the base plate 89, etching is completed, and pure water is injected to stop and clean the wafer, the temperature of the wafer sharply decreases. To do. At this time, the wafer shrinks, but since the wafer is pressed against the base plate 89 by the atmospheric pressure, the shrinkage cannot catch up and stress is generated. These stresses cause wafer cracking.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a surface processing apparatus which does not use a wax and is less likely to cause wafer cracking. is there.

[0010]

According to a first aspect of the present invention, there is provided a surface processing apparatus, wherein a substrate on which a wafer is placed is formed on a top surface of the substrate, and the substrate is formed in a tubular shape with an opening facing down. A wafer whose lower surface is opposed to the outer peripheral portion of the wafer mounting portion on the substrate, and a wafer disposed between the upper surface of the edge portion of the wafer and the cylindrical body, and for the processing liquid filled in the wafer. A sealing member which seals the edge portion, which is made of an elastic material, has a ring shape, is arranged between the base material and the cylindrical body, and has a V-shaped beam portion and a seal lip at the tip of the beam portion, The space formed by the beam portion, the seal lip, and the base material upper surface or the cylinder lower surface is evacuated to draw the base material and the cylindrical body together, and the seal lip is crushed and the beam portion is elastically deformed to separate the base material and the cylindrical body. And a drive cylinder for supporting suction.

Therefore, in the drive cylinder, the base material and the tubular body are attracted by the vacuumization of the space formed by the beam portion, the seal lip and the base material upper surface or the cylindrical lower surface, and the crushing margin of the seal lip and the elasticity of the beam portion. The base material and the cylindrical body are suction-supported by the deformation. In addition, the edge of the wafer is sealed with a sealing material in a part other than the drive cylinder.

As a result, in the conventional apparatus shown in FIG. 21, since the wafer 70 is brought into close contact with the base plate 89 by the vacuum of the vacuum chamber 90 of the masking jig to correct it, the space between the lower surface of the wafer 70 and the base plate 89 is reduced. When the vacuum is applied and the lower surface of the wafer 70 receives stress, etching proceeds, and the thickness is 10 μm.
Although it was feared that the wafer would be cracked when it was less than m, in the present invention, the mounting surface (back surface) on the wafer is not vacuumed, and the wafer is less likely to crack.

Here, as described in claim 2, the drive cylinder includes a main body, an upper beam portion extending upward from the main body, an upper seal lip at the tip of the beam portion, and a lower beam extending downward from the main body. And a lower seal lip at the tip of the beam portion, further comprising:
Like this, a through hole is provided in the main body of the drive cylinder, and through this through hole, an upper space formed by the upper beam portion and the lower surface of the cylinder, and a lower space formed by the lower beam portion and the upper surface of the base material. With the structure in which and are communicated with each other, the upper space and the lower space can have the same pressure.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is applied to an electrochemical stop etching apparatus, and assumes the case of manufacturing a semiconductor pressure sensor using a piezoresistive layer.

1 and 2 show an electrochemical stop etching apparatus. 1 is a plan view of the electrochemical stop etching apparatus, and FIG. 2 is a sectional view taken along line AA of FIG. Hereinafter, this electrochemical stop etching apparatus will be described in detail.

First, the masking pot 1 as an etching tank will be described with reference to FIG. Masking pot 1
Comprises a plate-shaped wafer base 2 as a base material and a tubular wafer pipe 3 as a tubular body. A silicon wafer 4 can be placed on the wafer base 2 and the wafer pipe 3 is provided on one side thereof. It is placed with its opening facing down. That is, the silicon wafer 4 is arranged so as to close the lower surface opening of the tubular wafer pipe 3. More specifically, the central portion of the wafer base 2 functions as a table on which the silicon wafer 4 is placed, and a communication hole 5 with the outside air is provided so that the masked surface of the silicon wafer 4 can keep its natural warp. . Further, a concave portion 6 is formed in an annular shape on the outer peripheral side of the wafer mounting portion of the wafer base 2, and the protruding portion 7 of the wafer pipe 3 is fitted into the concave portion 6. In this way, the recess 6 has a function of alignment. Further, on the outer peripheral side of the concave portion 6 in the wafer base 2 (around the wafer mounting portion)
Has a flat seal surface S1 formed in a ring shape, and the recess surface 8 is formed in a ring shape in the seal surface S1 to function as a vacuum pocket.

A wafer-shaped packing 9 is fixed to the inner peripheral portion of the lower surface of the wafer pipe 3, and the packing 9 is formed into a wafer shape so as to seal the upper surface of the edge portion of the silicon wafer 4. The wafer type packing 9 as a sealing member can seal against the etching liquid filled in the wafer pipe 3. A flat seal surface S2 is formed in an annular shape on the outer peripheral portion of the lower surface of the wafer pipe 3, and a concave portion 10 is formed in an annular shape in the seal surface S2 to function as a vacuum pocket. Here, the sealing surface S1 of the wafer base 2 and the sealing surface S2 of the wafer pipe 3
And are opposed to each other, and the recesses 8 and 10 are opposed to each other.

An X-shaped drive cylinder 11 is provided between the sealing surface S1 of the wafer base 2 and the sealing surface S2 of the wafer pipe 3.
Are arranged. The X-shaped drive cylinder 11 is made of an elastic material such as rubber. More specifically, 1 as an etching solution
In this example using an aqueous KOH solution at 10 ° C, EPDM is used.
Is used. FIG. 4 shows a plan view of the X-shaped drive cylinder 11. FIG. 5 is a sectional view taken along line BB of FIG. As shown in FIG. 5, the X-shaped drive cylinder 11 is a ring-shaped packing having an X-shaped cross section. More specifically, in FIG.
A beam portion 13 extends obliquely upward from the upper end of the cylinder body 12 on the inner peripheral side, and a beam portion 14 extends obliquely upward on the outer peripheral side from the upper end of the cylinder body 12. In addition, semicircular seal lips 15 and 16 are formed at the tips of the beam portions 13 and 14. Thus, the V-shaped beam portions 13 and 14 and the seal lip 1 at the tip of the beam portions
5 and 16. Similarly, a beam portion 17 extends obliquely downward from the lower end of the cylinder body 12 on the inner peripheral side, and a beam portion 18 extends obliquely downward from the lower end of the cylinder body 12 on the outer peripheral side. In addition, semicircular seal lips 19 and 20 are formed at the tips of the beam portions 17 and 18. Thus, the V-shaped beam portions 17 and 18 and the seal lips 19 and 20 at the tips of the beam portions are provided. And
With the X-shaped drive cylinder 11 arranged between the wafer base 2 and the wafer pipe 3, the upper beam portion 13,
An upper space (hereinafter, referred to as an upper vacuum chamber R1) is defined by the upper surface 14, the seal lips 15 and 16 and the lower surface S2 of the wafer pipe 3, and the lower beam portions 17 and 18, the seal lips 19 and 20, and the wafer base 2 are formed. A lower space (hereinafter referred to as a lower vacuum chamber R2) is defined by the upper surface S1. Further, as shown in FIG. 3, the wafer base 2 is provided with a vacuum exhaust port 22 communicating with the recess 8. An air venting device such as a vacuum pump is connected to the vacuum exhaust port 22.

Although the vacuum exhaust port 22 is provided on the wafer base 2 side in this example, the concave portion 1 is provided on the wafer pipe 3 side.
A vacuum exhaust port communicating with 0 may be provided, or both the wafer base 2 and the wafer pipe 3 may be provided with a vacuum exhaust port.

As shown in FIG. 4, the main body 12 of the X-shaped drive cylinder 11 is provided with through holes 21 at several intervals (eight in this example) on the circumference at equal intervals. As shown in FIG. 5, the upper and lower vacuum chambers R1 and R2 communicate with each other. With this through hole 21, a recess (vacuum pocket) 8,
The pressure of 10 is the same.

Further, the beam portions 13, 14, 1 projecting in four directions in the cross section of the X-shaped drive cylinder 11 of FIG.
Reference numerals 7 and 18 denote the insides of the recesses 8 and 10 (vacuum chambers R1 and R2).
At the time of non-drive at atmospheric pressure, the reaction force is sufficient to lift the wafer base 2 and the wafer pipe 3 (about 5K in this example).
g), and the wafer pipe 3 is supported on the wafer base 2 as shown in FIG. Further, when driving the inside of the recesses 8 and 10 (vacuum chambers R1 and R2) with a vacuum pump or the like to vacuum, the beam portions 13, 14, 17, and 18 are elastically deformed due to the pressure difference between the internal vacuum and the atmospheric pressure. 6, the wafer base 2 and the wafer pipe 3 are attracted and drawn to the wafer base 2 by the crushing margin of the seal lips 15, 16, 19, 20 and the elastic deformation of the beam portions 13, 14, 17, 18. The wafer pipe 3 is suction-supported. This driving force (about 40 kg in this example) acts as a sealing force for the silicon wafer 4. By the way, in this example, the silicon wafer 4
Unit seal length (in this case, the seal length refers to the length of the center of the ring-shaped seal surface) of 1.4 kg / c
A sealing force of m is obtained.

When the X-shaped drive cylinder 11 shown in FIG. 6 is driven, the wafer-shaped packing 9 for edge sealing provided on the wafer pipe 3 shown in FIG. 3 is used for sealing, and the electrode 25 provided on the wafer base 2 is removed. It is pressed against the silicon wafer 4.

The stroke for driving the X-shaped drive cylinder 11 is 0.5 mm. That is, the overall length of the X-shaped drive cylinder 11 is 0.5 mm shorter when driven in FIG. 6 than when not driven in FIG.

The masking pot 1 thus constructed is set in an etching apparatus provided with a swing mechanism as shown in FIG. 2, and an etching solution 23 is poured into the masking pot 1. In FIG. 2, the swing base 26 on which the pot 1 is placed and the swing cap 27 that closes the upper opening of the pot 1 are attached to the main body base 30 and the cap base 31 via the linear motion bearings 28 and 29 arranged at right angles. It is swingably supported in the horizontal direction (X-Y direction in FIG. 1).
Further, two columns 32 and 33 are interposed between the main body base 30 and the cap base 31. A liquid supply / drainage block 34 is fixed to the central portion of the cap base 31, and a liquid discharge pipe 35 hangs down from the central portion of the liquid supply / drainage block 34. A platinum diffusion plate 36 is fixed to the lower end of the drainage pipe 35. The diffusion plate 36 has a disc shape and is provided with a large number of holes. The plate 36 is immersed in the etching solution 23.

An injection port 37 is formed in the supply / drainage block 34, and the etching liquid can be injected into the masking pot 1 through the injection port 37. As shown in FIG. 1, the swing base 26 has rectangular holes 40a and 40b.
Is provided in the holes 40a and 40b.
a and 41b are rotatably fitted together. This eccentric cam 4
The drive shafts 42a and 42b of the drive shafts 1a and 41b are drivingly connected to a motor or the like, and the eccentric cam 41 is centered around the drive shafts 42a and 42b.
a and 41b rotate. Then, the eccentric cams 41a, 41
When b is rotated, the swing base 26 can be moved in the X and Y directions in FIG. More precisely, the swing base 26 moves in the X direction by the rotation of the eccentric cam 41a and in the Y direction by the rotation of the eccentric cam 41b.

FIG. 7 shows a cross section of a semiconductor pressure sensor to be processed using an electrochemical stop etching device. In FIG. 7, an N-type epitaxial layer 51 having a thickness of 10 μm is formed on one surface of a P-type silicon substrate 50 having a (110) plane orientation.
Is configured. The P-type silicon substrate 50 is formed with a recess 53 that is open on one surface, and the bottom surface 53 a of this recess 53 is
Constitutes a thin portion 54. This thin portion 54 serves as a sensor diaphragm. The recess 53 is formed by electrochemical etching.

[0027] The N-type epitaxial layer 51 is formed a P ⁺ -type impurity diffusion layer 55, the P ⁺ -type impurity diffusion layer 55
Becomes a piezoresistor for sensing strain. A silicon oxide film 56 is formed on the surface of the N-type epitaxial layer 51. The P ⁺ -type impurity diffusion layer 55 is electrically drawn out to the surface side of the silicon oxide film 56 by the aluminum wiring 57.

During the etching for forming the concave portion 53, the etching is performed in a state in which a predetermined region on the surface to be etched of the P-type silicon substrate 50 is covered with the mask material 58, and the region without the mask material 58 is removed. The silicon is etched to form the recess 53.

Next, an etching method using an electrochemical stop etching device will be described. First, as shown in FIG. 3, the silicon wafer 4 is set in the masking pot 1. At this time, instead of masking with the wax 79 shown in FIG. 18, it is masked with the wafer-type packing 9 for edge sealing shown in FIG. This masking action will be described in detail. Before the formation of the recess 53 in FIG. 7, the silicon wafer 4 on which the mask material 58 is arranged is prepared. The silicon wafer 4 is placed on the wafer base 2 of FIG. 3 so that the surface to be processed faces upward, and the wafer pipe 3 is covered with the X-shaped drive cylinder 11 interposed therebetween, and a recess (pocket) is formed by a vacuum pump (not shown) or the like. 8 and 10 are evacuated. When the X-shaped drive cylinder 11 is evacuated from the state shown in FIG.
As shown in FIG. 3, the wafer base 2 and the wafer pipe 3 are contracted vertically due to the atmospheric pressure difference, and the wafer base packing 9 provided for the wafer pipe 3 is used to seal the edge surface of the silicon wafer 4. As described above, in the masking mechanism of this example, since the fastening force at the time of masking is obtained by contracting the X-shaped drive cylinder 11 as described above, the sealing force is applied over the entire circumference as compared with the bolt fastening using the jig shown in FIG. It becomes uniform and preferable. Also, the silicon wafer 4
Since the sealing force is applied only to the edge surface of the wafer, the warp at the center of the wafer is not corrected as compared with the apparatus shown in FIG.
It is also possible to manufacture diaphragms of m or less.

During unmasking (non-driving), the vacuum of the concave portions (pockets) 8 and 10 is released, so that the X-shaped driving cylinder 11 is moved from the wafer base 2 while keeping the silicon wafer 4 horizontal. Since the wafer pipe 3 is separated, stress such as twisting is not applied to the silicon wafer 4.

Furthermore, by appropriately evacuating and opening the recesses (pockets) 8 and 10, the speed of 4 inches /
It is also possible to automatically mask a 200 μm thick wafer.
More specifically, the speed can be optimized by evacuating and opening the air at about 1 atmosphere / 30 seconds.

Further, since the treatment is carried out only in the masking pot 1, there is a high degree of freedom in designing the outer shape of the masking pot 1, and attachment of a feed electrode for electrochemical stop etching and attachment of the diaphragm thickness measuring sensor 47 shown in FIG. Will be easier.

Here, further mentioning the effect of using the X-shaped drive cylinder 11 as the packing, since the etching treatment tank is used under high temperature, the initial dimension changes due to the compression set of the packing and the thermal expansion of the constituent members. However, it is necessary to hold down with a force of 5 Kgf to 10 Kgf when assembling the pot. In order to absorb the dimensional change, there is a means to increase the tightening margin of the packing, but in the long term, compression set occurs and it is not a fundamental solution. This is because the packing sealing principle generates a sealing force by the reaction force due to compression. In the X-shaped drive cylinder 11 of this configuration, the seal lips 15, 16, 19, 20 at the four tip portions contact the wafer pipe 3 and the wafer base 2 to seal the recesses (vacuum pockets) 8, 10. If the concave portions 8 and 10 are evacuated in this state, the beam portions 13 and 1 of the X-shaped drive cylinder 11 are
4, 17 and 18 bend due to elastic deformation to draw the wafer pipe 3 and the wafer base 2 and the wafer type packing 9 comes into contact with the silicon wafer 4 to balance it. Since the vacuum pocket sealing force is generated by the reaction force of the elastic deformation of the beam portions 13, 14, 17, and 18, the sealing lips 15, 16, and 1 are generated.
Even if compression set occurs in 9, 20, it becomes possible to seal.
Also, with respect to the wafer type packing 9, it is possible to prevent a seal defect by making the pullable stroke between the wafer pipe 3 and the wafer base 2 sufficiently large with respect to the compression set.

Returning to the description of the etching method, the masking pot 1 shown in FIG. 3 is set in the electrochemical stop etching apparatus shown in FIG. 2, the swing cap 27 is mounted, and the clamp screws 43 and 44 can swing in the XY directions. To support. Then, the etching liquid 23 is injected into the masking pot 1 through the injection port 37 of the supply / drainage liquid block 34. At this time, the resistance measuring device 45 is used to move the electrode 25
It was confirmed that the silicon wafer 4 was immersed in the etching solution 23 by measuring the resistance between the electrodes 46 connected to
-Start Y swing. Etching liquid 23 due to this rocking
Immersion in the etching solution 23 with stirring is performed for a predetermined time.

Subsequently, the etching liquid 23 is drained from the drain pipe 35. The etching end time is determined by measuring the etching amount with the thickness measuring sensor 47 (see FIG. 2) provided on the wafer base 2. The sensor 47 of FIG. 2 shows an example of a measuring device that measures the thickness from one side by utilizing the double reflection of the etched surface of the silicon wafer 4 and the opposite surface.

In the apparatus shown in FIG. 2, the etching solution 23 is drained from the drainage pipe 35. However, without using the drainage pipe 35, the masking pot 1 is inverted by a reversing mechanism or the like to etch the etching solution 23. May be discharged.

When the etching is completed in this way, FIG.
As shown in FIG. 3, the masking pot 1 is inverted by an inverting mechanism (not shown) or the like, and in this state, the processed surface of the wafer 4 is shower-washed by the shower nozzle 60 for washing with water. The cleaning liquid is discharged through the water passage 61. In this cleaning process, the cleaning liquid sprayed from below is completely washed off on the wafer surface.

Then, the inside of the recesses 8 and 10 in FIG. Then, from the wafer base 2 to the wafer pipe 3 in FIG.
And the silicon wafer 4 is removed from the wafer base 2. At this time, since the atmospheric pressure is present between the back surface of the silicon wafer 4 and the wafer base 2, the silicon wafer 4 can be easily removed without sticking to the wafer base 2. That is, in the apparatus shown in FIG. 21, the air between the wafer 70 and the base plate 89 is decompressed and the wafer 70 is in close contact with the base plate 89.
Even if 0 becomes the atmospheric pressure, a depressurized minute space may remain between the wafer 70 and the base plate 89, and the wafer 70 may not be easily removed from the base plate 89. Without this, the silicon wafer 4 can be easily removed from the wafer base 2.

As a result, as shown in FIG. 7, a predetermined region of the silicon wafer (52) is etched to form a recess 53. As described above, the etching target surface of the silicon wafer 4 is supported upward on the bottom surface of the masking pot 1 of FIG. 2 and the force for masking the edge surface of the silicon wafer 4 by the X-shaped drive cylinder 11 is made uniform. It was possible to obtain a wafer-size processing tank (masking pot 1) that also doubled as masking.

Therefore, by making the surface of the silicon wafer 4 to be processed upward with respect to the etching liquid, it becomes easy to remove bubbles adhering during the supply of the processing chemicals and the reaction gas generated during the processing, and Unprocessed chips and defective shapes due to bubbles can be eliminated. In addition, since the treatment liquid can be treated in a small amount (internal volume of the masking pot 1), significant resource saving can be realized, and continuous washing is performed on the spot without taking out the silicon wafer 4 from the masking pot 1. This can be performed, and it is also possible to reduce the variation in thickness within the surface of the silicon wafer 4 caused by the progress of the reaction during transportation as in the conventional case.

Further, since the liquid contact part is limited to the inside of the masking pot 1, even if the masking work or contamination of the pot handling occurs on the outer surface of the masking pot 1,
The processing liquid is not contaminated at all, and work can be performed safely.

By using the masking pot 1 as described above, the conventional dipping treatment process can be easily reproduced, and the masking work and equipment scale can be greatly improved to realize a highly productive surface treatment process. it can.

As described above, this embodiment has the following features. (A) The X-shaped drive cylinder 11 shown in FIG.
1 and the sealing surface S2 of the wafer pipe 3,
The V-shaped beam portions 13, 14 and 17, 18 of FIG. 5 and the seal lips 15, 16, 19, 20 at the tip of the beam portions
And beam portions 13, 14 and 17, 18 and seal lips 15, 16 and 19, 20 and wafer base 2
The upper and lower vacuum chambers R1 and R2 formed by the sealing surface S1 of the wafer pipe 3 and the sealing surface S2 of the wafer pipe 3 to draw the wafer base 2 and the wafer pipe 3 together to crush the seal lips 15, 16, 19, 20. The wafer base 2 and the wafer pipe 3 are suction-supported by elastic deformation of the projections and the beam portions 13, 14, 17, and 18. Accordingly, the wafer base 2 and the wafer pipe 3 are suction-supported by the X-shaped drive cylinder 11 under vacuum, and the silicon wafer 4 is attached to the wafer-shaped packing 9 at a portion different from the X-shaped drive cylinder 11. The edges are sealed. As a result, in the conventional apparatus shown in FIG. 21, a vacuum is created between the lower surface of the wafer 70 and the base plate 89, etching progresses in a state where the lower surface of the wafer 70 is stressed, and cracks occur when the diaphragm thickness becomes 10 μm or less. Although there is a fear that it will happen, in the present embodiment,
The mounting surface (rear surface) of the silicon wafer 4 is not vacuumed and the wafer is not cracked. Specifically, silicon wafer 4
The backside of the wafer can be brought to atmospheric pressure, and the silicon wafer 4 is held against the wafer base 2 at atmospheric pressure with a slight gap on the backside of the wafer, making it easy even when the wafer temperature drops during etching stop / cleaning. No shrinkage occurs and no stress is generated, and wafer cracking is avoided. further,
Since the back surface of the wafer is at atmospheric pressure, the sensor 47 and the like can be easily provided without sealing. (B) The upper vacuum chamber R1 is attached to the X-shaped drive cylinder 11 in FIG.
Since the through hole 21 that connects the lower vacuum chamber R2 and the lower vacuum chamber R2 is provided, the upper vacuum chamber R1 and the lower vacuum chamber R2 can be set to the same pressure, which is practically preferable.

Besides the above-described embodiments, the following may be carried out. In FIG. 5, the X-shaped drive cylinder 11 includes a cylinder body 12 and beam portions 13, 1.
4,17,18 and seal lips 15,16,19,2
However, as shown in FIG. 9, the drive cylinder 11 includes a cylinder body 12 and beam portions 17, 1.
8 and the seal lips 19 and 20, and the cylinder body 12 is fixed to the wafer pipe 3 with bolts B1 and B2.
The lower surface of the wafer base 2 may be fastened and the wafer base 2 may be sucked by vacuuming as shown in FIG.

Alternatively, as shown in FIG. 11, the drive cylinder 11 includes a cylinder body 12 and beam portions 13 and 14.
And the seal lips 15 and 16 are provided, the cylinder body 12 is fastened to the upper surface of the wafer base 2 with bolts B3 and B4, and the wafer pipe 3 is sucked by vacuuming as shown in FIG. May be.

Further, instead of the electrochemical stop etching apparatus, as shown in FIG. 13, it may be applied to an immersion type plating apparatus which does not apply a voltage. Further, as shown in FIG. 14, it may be applied to a plating apparatus. That is, pot 1
The silicon wafer 4 is attached (masked) to the pot, the plating solution 63 is put into the pot 1, and power is supplied from the plating power supply 66 to the cathode electrode 64 provided on the wafer pipe 3 and the anode electrode 65 immersed in the plating solution 63. You may make it perform a plating process. An example of plating by this plating apparatus is a case where bumps (projection electrodes) having a diameter of about several tens to 100 μm are formed by electroplating to manufacture a flip chip.

In the above description, the case where the diaphragm of the semiconductor pressure sensor is formed as shown in FIG. 7 has been described. However, when the thin portion (beam portion) 75 of the semiconductor acceleration sensor as shown in FIG. 16 is formed. Etc. can be used.

[Brief description of drawings]

FIG. 1 is a plan view of an electrochemical etching apparatus according to an embodiment.

2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view of a masking pot.

FIG. 4 is a plan view of a drive cylinder.

FIG. 5 is a cross-sectional view of a driving cylinder in a non-driving state.

FIG. 6 is a plan view of the drive cylinder in a driven state.

FIG. 7 is a sectional view of a semiconductor pressure sensor.

FIG. 8 is a plan view of an electrochemical etching device.

FIG. 9 is a sectional view of a driving cylinder of another example in a non-driving state.

FIG. 10 is a sectional view of a driving cylinder of another example in a driven state.

FIG. 11 is a sectional view of a drive cylinder of another example in a non-driven state.

FIG. 12 is a sectional view of a drive cylinder of another example in a driven state.

FIG. 13 is a vertical sectional view of an etching apparatus.

FIG. 14 is a vertical cross-sectional view of the plating apparatus.

FIG. 15 is a plan view of a wafer.

FIG. 16 is a diagram showing a sensor chip.

FIG. 17 is a diagram showing a sensor chip.

FIG. 18 is a view for explaining masking of a wafer.

FIG. 19 is a diagram for explaining a wafer etching process.

FIG. 20 is a view for explaining a masking jig for a wafer.

FIG. 21 is a sectional view for explaining a conventional device.

FIG. 22 is a view for explaining the warp of the wafer.

[Explanation of symbols]

1 ... Masking pot, 2 ... Wafer base, 3 ... Wafer pipe, 4 ... Silicon wafer, 9 ... Wafer type packing,
11 ... X-shaped drive cylinder, 12 ... Cylinder body, 13 ...
Beam part, 14 ... Beam part, 15 ... Seal lip, 16
... Seal lip, 17 ... Beam part, 18 ... Beam part, 1
9 ... Seal lip, 20 ... Seal lip, S1, S2 ...
Sealing surface.

Continuation of front page (56) Reference JP-A-8-255780 (JP, A) JP-A-11-154663 (JP, A) JP-A-6-120204 (JP, A) JP-A-7-335610 (JP , A) Actual development Sho 63-89238 (JP, U) Actual development Sho 59-70336 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/304 H01L 21/306 H01L 21/308

Claims (3)

(57) [Claims] 1. A substrate on which an upper surface of a wafer is mounted, and a substrate which has a cylindrical shape and is placed on the substrate with an opening facing down, and the lower surface of which is mounted on the substrate. A cylindrical body facing the outer peripheral portion of the portion, a seal member arranged between the upper surface of the edge portion of the wafer and the cylindrical body, and sealing the wafer edge portion against the processing liquid filled in the cylindrical body; It is made of a material, has a ring shape, and is arranged between the substrate and the cylindrical body, and has a V-shaped beam portion and a seal lip at the tip of the beam portion, and the beam portion, the seal lip, and the upper surface of the substrate. Or a drive cylinder for attracting and supporting the base material and the tubular body by pulling the base material and the tubular body together by evacuating the space formed by the lower surface of the tubular body to crush the seal lip and elastically deforming the beam portion. A surface processing device characterized in that 2. The drive cylinder includes a main body, an upper beam portion extending upward from the main body, an upper seal lip at the tip of the beam portion, a lower beam portion extending downward from the main body, and a lower side of the tip portion of the beam portion. The surface processing apparatus according to claim 1, further comprising a seal lip. 3. A through hole is provided in the main body of the drive cylinder, and in the through hole, an upper space formed by the upper beam portion and the lower surface of the tubular body, and a lower side formed by the lower beam portion and the upper surface of the base material. The surface processing apparatus according to claim 2, which is in communication with a space.