JP5530653B2 - Substrate holding jig and cleaning device - Google Patents

Description

  The present invention relates to a substrate holding jig for holding a substrate during cleaning in a cassetteless cleaning apparatus using a batch type megasonic.

Conventionally, cleaning of engineering parts and substrates has been generally performed using an ultrasonic cleaning apparatus.
FIG. 4 shows a schematic diagram of an example of a general ultrasonic cleaning apparatus.
As shown in FIG. 4, a general ultrasonic cleaning apparatus 101 includes a cleaning tank 102 that contains a cleaning liquid 107 for cleaning an object to be cleaned 104, and propagation water 108 for propagating ultrasonic waves to the cleaning tank 102. And a vibration for applying ultrasonic waves to the propagation water 108 by a vibrator 109 made of a piezoelectric element made of ceramic, for example, provided on the outer wall surface of the ultrasonic propagation tank 103. A plate 105 or the like is provided. Further, the object to be cleaned 104 is held in the cleaning tank 102 by the substrate holding jig 106 or the like, and is immersed in the cleaning liquid in the cleaning tank 102.

  Then, the ultrasonic wave applied by the diaphragm 105 is propagated to the cleaning tank 102 through the propagation water 108, and a standing wave is formed with the liquid surface of the cleaning liquid 107, the cleaning tank wall, and the like as a boundary. At this time, the cleaning liquid that hits the antinode of the standing wave vibrates greatly, and the object to be cleaned 104 is cleaned with the sound pressure generated by the vibration.

  In recent years, in ultrasonic cleaning of semiconductor parts and the like, a megasonic cleaning apparatus using high frequency ultrasonic waves such as 1 MHz has been used in terms of, for example, effective in removing particles from a wafer and improving particle quality. Yes. Megasonic has the advantage that it is difficult to generate standing waves like those in the wavelength range of ultrasonic waves used in the past.

JP-A-6-204197

  In a batch type megasonic cleaning apparatus, a resin member is generally used as a substrate holding jig for holding a substrate during cleaning so as not to cause damage to the substrate. However, since the resin tends to absorb ultrasonic waves, the cleaning effect by the megasonic is reduced, and the resin itself is also exposed to damage by ultrasonic waves, resulting in a problem of particle generation. Further, as a characteristic of the resin, the substrate holding jig is displaced due to a temperature change, thereby causing a shift in the holding position of the substrate, which causes problems such as conveyance trouble and concern about damage to the substrate.

  For example, Patent Document 1 discloses a wafer boat that holds a substrate during cleaning. However, when this wafer boat is used in a megasonic cleaning device, the area of the resin part exposed to ultrasonic waves is large and is insufficient for reducing damage. Since it is necessary to change the groove pitch depending on the temperature, it is difficult to actually adjust the problem and the cleaning efficiency is not good.

  The present invention has been made in view of the above problems, and is resistant to damage by ultrasonic waves in substrate cleaning in a megasonic cleaning apparatus, can prevent a substrate transport trouble due to displacement of the substrate holding position, and is excellent. An object is to provide a substrate holding jig capable of performing cleaning.

  In order to achieve the above object, according to the present invention, in a batch-type megasonic cleaning apparatus, a substrate holding jig for holding a substrate in a cleaning tank at the time of cleaning, at least holding the substrate in the cleaning tank. And two or more quartz support members having both ends connected to the side plate, and a resin holding member having one holding groove and attached to the quartz support member. The resin holding member is attached to the quartz support member so as not to come into contact with other resin holding members, and the peripheral edge of the substrate is fitted into the holding groove of the resin holding member. The substrate holding jig is characterized in that the substrate is held.

As described above, the substrate holding jig of the present invention is made of resin as the holding member that directly contacts the substrate, and made of quartz as the supporting member that supports the holding member. The ultrasonic wave is reduced, the generation of particles is reduced, the substrate cleaning effect is increased, and the jig is also resistant to ultrasonic damage to the jig, thereby preventing deterioration and extending the jig replacement cycle. And since a holding part is resin, generation | occurrence | production of the damage | wound to the board | substrate to hold | maintain is prevented. In addition, since the area of the resin holding member exposed to ultrasonic waves is reduced, damage to the resin part is reduced, the replacement cycle is longer than when the entire jig is made of resin, and only the holding member is replaced. This can reduce costs. Furthermore, heat generation by the ultrasonic waves of the resin holding member is also suppressed. In addition, by attaching the holding groove of the resin holding member to one and not attaching the other resin holding member to the quartz support member, the quartz portion hardly expands due to temperature change, and the resin Even if the holding member is thermally expanded, there is one holding groove and there is no influence between the adjacent members. Therefore, the position of the holding groove is not substantially changed, and the substrate holding position is hardly displaced. Accordingly, troubles in substrate transportation are less likely to occur.
As described above, with the substrate holding jig of the present invention, in the megasonic cleaning, there is no trouble in transporting the substrate, and there is no worry about damage to the substrate or particles, and good cleaning is efficiently performed at a low cost. be able to.

At this time, the resin holding member is preferably made of a fluororesin.
Thus, a fluororesin is suitable because it has high strength and high resistance to cleaning liquid.

At this time, it is preferable that the resin-made holding member is cylindrical, and the resin-made holding member is attached by being fitted into a hole provided in the quartz-made support member.
Thus, if the resin-made holding member is cylindrical, it is easy to manufacture, and it is easy to mount and replace by fitting into the hole of the quartz support member. Therefore, it can be configured simply and inexpensively.

At this time, the resin holding member attached to the quartz support member is the quartz support member on the vibrator side that generates ultrasonic waves in the megasonic cleaning device, and the opposite side is the resin holding member. It is preferable that they are arranged in such a manner.
With such an arrangement, the ultrasonic wave from the vibrator hits the quartz support directly, and the resin holding member on the opposite side is not directly exposed to the ultrasonic wave, so the absorption of ultrasonic waves is further reduced and the cleaning effect Is even higher. Furthermore, since the ultrasonic wave is shielded by the quartz support member, damage to the resin holding member and heat generation are further suppressed as compared with the case of direct exposure.

The present invention is also a megasonic cleaning apparatus for cleaning a substrate, comprising at least the substrate holding jig of the present invention, and vibrating the substrate held in the cleaning tank by the substrate holding jig. Provided is a megasonic cleaning apparatus that performs cleaning while applying ultrasonic waves generated by a child.
With such a megasonic cleaning apparatus, in the megasonic cleaning, there is no trouble in transporting the substrate, and there is no fear of damage to the substrate or particles, and good cleaning can be performed efficiently at a low cost.

  As described above, with the substrate holding jig of the present invention, in the megasonic cleaning, there is no trouble in transporting the substrate, and there is no worry about damage to the substrate or particles, and good cleaning is efficiently performed at a low cost. be able to.

It is a schematic enlarged view of the resin-made holding member attached to the quartz support member of the board | substrate holding jig of this invention. It is a schematic sectional drawing which shows the state which attached the board | substrate holding jig of this invention to the megasonic cleaning apparatus. It is a schematic plan view which shows the state which attached the board | substrate holding jig of this invention to the megasonic cleaning apparatus. It is the schematic of the conventional common ultrasonic cleaning apparatus. It is the figure which observed the particle number of the board | substrate after washing | cleaning in an Example and a comparative example, and the particle | grains of the board | substrate after washing | cleaning. It is the graph which shows the difference by the output of the ultrasonic wave of the particle number of the board | substrate after washing | cleaning, and the figure which observed the particle | grains of the board | substrate after washing | cleaning. It is a figure which shows the washing | cleaning process in an Example and a comparative example.

  A substrate holding jig that holds a substrate during cleaning using a megasonic cleaning device is thermally expanded due to damage caused by ultrasonic waves, generation of particles based on the damage, temperature of the cleaning liquid, and heat generated by the jig itself due to ultrasonic waves. There have been problems such as substrate transport troubles due to displacement of the holding position and reduction in cleaning effect due to resin megasonic absorption.

As a result of intensive studies by the present inventors on the above problems, quartz having a very low thermal expansion coefficient of 5.5 × 10 ⁻⁷ / ° C. and high strength is used as a support member, Furthermore, it was conceived that resin is used only for the holding member of the substrate and this is attached to the quartz support member. Further, by forming one holding groove in one resin holding member and attaching each resin holding member so as not to contact each other, the displacement of the holding groove due to the thermal expansion of the resin and the adjacent The present invention has been completed by finding that the influence is eliminated and displacement of the substrate holding position can be prevented.

Hereinafter, the substrate holding jig of the present invention will be described in detail as an example of an embodiment with reference to the drawings. However, the present invention is not limited to this.
FIG. 1 is a schematic enlarged view of a resin holding member attached to a quartz support member of a substrate holding jig of the present invention. FIG. 2 is a schematic sectional view showing a state in which the substrate holding jig of the present invention is attached to a megasonic cleaning apparatus, and FIG. 3 is a schematic plan view thereof.

As shown in FIGS. 2 and 3, the megasonic cleaning apparatus 10 to which the substrate holding jig 11 of the present invention can be applied includes a cleaning liquid 16 for immersing and cleaning a substrate W such as a silicon single crystal wafer. The cleaning tank 14 to be stored, the ultrasonic propagation tank 18 to store the propagation water 19 for propagating the ultrasonic waves to the cleaning tank 14, and the ultrasonic wave transmitted by the vibrator 17 disposed below the ultrasonic propagation tank 18. A diaphragm 20 to be applied to 19 is provided.
Here, as the cleaning liquid 16, for example, a chemical liquid such as SC-1 solution (a mixture of ammonia water, hydrogen peroxide water and pure water) can be used, or pure water can also be used. it can. Moreover, the liquid temperature of the washing | cleaning liquid 16 can be 5-90 degreeC, for example.

In the megasonic cleaning device 10, a vibrator 17 and a diaphragm 20 are disposed below the ultrasonic wave propagation tank 18. The vibration plate 20 can apply ultrasonic vibration from the vibrator 17 to the propagation water 19 and apply ultrasonic vibration from below the substrate W to be cleaned.
Here, the natural frequency of the vibrator 17 can be set to, for example, 500 KHz to 5 MHz, particularly 750 KHz to 1.5 MHz. These conditions may be determined according to the purpose of cleaning, and are not particularly limited. However, the use of high-frequency ultrasonic waves of about 1 MHz can enhance the particle removal effect.

  As shown in FIGS. 1 to 3, the substrate holding jig 11 of the present invention includes an opposing side plate 15 for holding the substrate W in the cleaning tank 14, and two or more side plates 15 having both ends connected to the side plate 15. A quartz support member 12 and a resin holding member 13 having one holding groove 21 and attached to the quartz support member 12 are provided. The resin holding member 13 is connected to the other resin holding members 13. The substrate W is attached to the quartz support member 12 so as not to make contact, and the substrate W is held by fitting the peripheral portion of one substrate W into one holding groove 21 of the resin holding member 13. .

  As described above, the substrate holding jig of the present invention is made of resin, and the support member to which the holding member is attached is made of quartz, so that the resin portion as a whole is small, so that it is absorbed during cleaning. The sound wave is reduced, the substrate cleaning effect is enhanced, and the jig is also resistant to ultrasonic damage, so that deterioration is prevented and the jig replacement cycle is extended. And since a holding part is resin, generation | occurrence | production of the crack to the board | substrate to hold | maintain is prevented. In addition, since the area of the resin holding member exposed to ultrasonic waves is reduced, damage to the resin part is reduced, the replacement cycle is longer than when the entire jig is made of resin, and only the holding member is replaced. This can reduce costs. Furthermore, heat generation by the ultrasonic waves of the resin holding member is also suppressed. In addition, by attaching the holding groove of the resin holding member to one and not attaching the other resin holding member to the quartz support member, the quartz portion hardly expands due to temperature change, and the resin Even if the holding member is thermally expanded, there is one holding groove and there is no influence between the adjacent members. Therefore, the position of the holding groove is not substantially changed, and the substrate holding position is hardly displaced. Therefore, when the substrate is held or taken out from the substrate holding jig by the robot arm or the like, there is almost no conveyance trouble because the substrate is at the correct position of the jig in the present invention.

  For example, as shown in FIG. 2, the side plate 15 can be attached to the upper part of the cleaning tank 14, and the material is not particularly limited. Is also preferable because it has a sufficient amount. Further, the side plate 15 may be fixed, or may be attached so as to be movable during and before and after cleaning.

At this time, the resin holding member 13 is preferably made of a fluororesin such as Teflon (registered trademark), for example.
A fluororesin is preferred because of its high strength and strong resistance to cleaning liquid.

At this time, as shown in FIGS. 1 to 3, the resin holding member 13 is cylindrical, and the resin holding member 13 is attached by being fitted into a hole provided in the quartz support member 12. It is preferable.
Thus, if the resin-made holding member is cylindrical, it is easy to manufacture, and it is easy to mount and replace by fitting into the hole of the quartz support member.
In addition, the interval between the resin holding members is not particularly limited, but if the interval is increased more than necessary, the number of substrates to be cleaned is reduced, so that the adjacent resin holding members are also at the temperature of the cleaning liquid. It only has to swell and contact.

At this time, as shown in FIGS. 2 and 3, the resin holding member 13 attached to the quartz support member 12 has the quartz support member 12 on the vibrator 17 side that generates ultrasonic waves in the megasonic cleaning apparatus 10. It is preferable that the other side is disposed so as to be the resin holding member 13.
With such an arrangement, the ultrasonic wave from the vibrator hits the quartz support directly, and the resin holding member on the opposite side is not directly exposed to the ultrasonic wave, so the absorption of ultrasonic waves is further reduced and the cleaning effect Is further increased, and damage to the resin holding member and heat generation are further suppressed.

  1 and 2 show a megasonic cleaning apparatus having a vibrator on the lower side. However, the megasonic cleaning apparatus in which the vibrator is installed beside the cleaning tank in order to apply ultrasonic waves from the lateral direction is also shown in FIG. The substrate holding jig of the invention can be applied, in which case the quartz support member can be arranged on the outside and the resin holding member can be arranged on the inside.

Further, when the quartz support member 12 and the resin holding member 13 are arranged as described above, the resin holding member is not completely hidden from the lower side (vibrator side) by the quartz support member. In order to prevent the resin-made holding member from being exposed to ultrasonic waves, it is preferable to adjust the width of the quartz support member to be wide.
In this way, the projection area of the resin holding member when viewed from the vibrator side is made as small as possible than the quartz support member, and most preferably is completely hidden (projection of the resin holding member with the quartz support member). Area ratio 0%).
Further, it is preferable to adjust the thickness of the quartz support member 12 as viewed from the vibrator side so as to be removed from the ultrasonic resonance conditions. Thereby, damage to the resin holding member attached to the quartz support member can be further reduced, and deterioration of the resin due to heat generation can be further suppressed.

  As described above, with the substrate holding jig of the present invention, in the megasonic cleaning, there is no trouble in transporting the substrate, and there is no worry about damage to the substrate or particles, and good cleaning is efficiently performed at a low cost. be able to.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these.
Example 1
Using a megasonic cleaning apparatus equipped with the substrate holding jig of the present invention as shown in FIGS. 1 to 3, five silicon substrates having a diameter of 300 mm after mirror polishing were subjected to megasonic cleaning for 10 minutes. The material of the holding member used was a fluororesin. The cleaning liquid used was a mixed liquid of ammonia, hydrogen peroxide and water (SC-1 solution), and the mixing ratio was 1: 1: 10. The temperature of the cleaning liquid was 50 ° C., and the frequency of ultrasonic waves was 1 MHz. A total of 200 washes were performed using the same jig under the same conditions.
As a result, no conveyance trouble occurred once, and neither the jig nor the substrate was damaged, and good cleaning was possible. Further, the number of particles on the substrate after the cleaning was reduced as compared with Comparative Example 1.

(Comparative Example 1)
Under the same conditions as in Example 1, however, the substrate holding jig was attached so that the resin holding member was a rectangular parallelepiped and was connected to the quartz support member by bringing adjacent resin holding members into contact with each other. A silicon substrate having a diameter of 300 mm after mirror polishing was cleaned using a polishing tool.
As a result, the conveyance trouble occurred three times, and the silicon substrate was also scratched.

(Example 2, comparative example 2)
A substrate holding jig (quartz stand) of the present invention as shown in FIGS. 1 to 3 is installed in each cleaning tank of a megasonic apparatus having five cleaning tanks (Example 2), and the whole is made of resin. A silicon substrate having a diameter of 300 mm after mirror polishing was cleaned using the prepared substrate holding jig (resin stand) (Comparative Example 2). At this time, the quartz stand has a quartz support member arranged on the vibrator side arranged below the apparatus, and the resin holding member is installed so as to be completely hidden from the vibrator side so that it is not directly exposed to the ultrasonic wave. did. The substrate was transported between these cleaning tanks by a robot arm to a stand.
Using the apparatus as described above, the substrate is cleaned by the cleaning process as shown in FIG. 7 in the order of steps 1-5, and the temperature of the solution at the time of cleaning with the SC-1 solution in step 2 is 70 ° C. Under the three conditions of (Condition 1), 60 ° C. (Condition 2), and 50 ° C. (Condition 3), cleaning was performed for five substrates under each condition. Except for step 2, washing was performed with DIW (pure water). Moreover, as shown in FIG. 7, in steps 2 and 3, megasonic was applied, but this output was set to 540W.

FIG. 5 shows the results of measuring the particles on the substrate surface cleaned as described above with a high-precision particle counter (manufactured by KLA Tencor, Surfscan SP2, High resolution mode, minimum measurement particle: ≧ 37 nm).
As shown in FIG. 5, the number of particles decreases as the substrate is cleaned under conditions where the solution temperature is high, but the particles are much larger when cleaned with the quartz stand of the present invention than with the resin stand. Has been reduced. This is because the resin absorbs the megasonic in the case of the resin stand, and the cleaning effect is reduced, whereas in the case of the quartz stand of the present invention, the quartz support member allows the megasonic to permeate better and the cleaning effect is reduced. This is considered to be because there was almost no reduction. Further, in the case of the comparative example using the resin stand, the conveyance trouble occurred more frequently as the solution temperature was higher. However, the conveyance trouble did not occur in the quartz stand of the present invention.
In addition, the quartz stand of the present invention has a great cleaning effect even at a low temperature such as 50 ° C., so the liquid temperature does not necessarily need to be as high as 70 ° C. Accordingly, scattering due to energy costs and liquid evaporation can be prevented, and the supply of new liquid can be suppressed. In this respect, the cost can be reduced. Furthermore, since the amount of etch-off can be reduced at a low temperature, deterioration of the surface roughness of the wafer can be prevented.

(Comparative Example 3)
Next, using a resin stand, the same cleaning conditions and conditions as in Condition 1 of Comparative Example 2 except that the output of Megasonic was 540 W (100%) and 270 W (50%), the same as Condition 1, respectively. went. FIG. 6 shows the result of measuring the substrate particles after the cleaning using the same apparatus and method as in Example 2 and Comparative Example 2.
As shown in FIG. 6, it can be seen that the higher the output of megasonic, the higher the cleaning effect, and the reduction of the particles on the substrate. However, since the cleaning was performed with a resin stand, in the case of cleaning performed at an output of 540 W (100%), when cleaning was performed a plurality of times, the resin was deteriorated and the number of particles increased again.

(Example 3, Comparative Example 4)
Next, using the cleaning device (Example 3) in which the quartz stand is installed and the cleaning device (Comparative Example 4) in which the resin stand is installed, the same conditions and the cleaning process as in Condition 3 of Example 2 and Comparative Example 2 However, in both cases, cleaning was performed with a megasonic output of 750 W, respectively.
Even in this case, in the case of the quartz stand, the cleaning can be performed satisfactorily, the cleaning effect is higher than the condition 3 of Example 2 in which only the output is different, and the particles are reduced. Further, in the case of the resin stand, the deterioration was quicker than the condition 3 of Comparative Example 2 in which only the output was different, and the particles increased significantly.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

10 ... Megasonic cleaning device, 11 ... Substrate holding jig,
12 ... Quartz support member, 13 ... Resin holding member, 14 ... Cleaning tank,
15 ... side plate, 16 ... cleaning liquid, 17 ... vibrator, 18 ... ultrasonic wave propagation tank,
19 ... Propagating water, 20 ... Diaphragm, 21 ... Holding groove, W ... Substrate.

Claims (3)

In a batch type megasonic cleaning apparatus, a substrate holding jig for holding a substrate in a cleaning tank at the time of cleaning, at least opposite side plates for holding the substrate in the cleaning tank, and both ends of the side plate Two or more quartz supporting members connected to each other and a resin holding member having one holding groove and attached to the quartz supporting member, the resin holding member holding another resin It is those attached to the quartz support member so as not to contact the member, which board by fitting the peripheral portion of the substrate to the holding groove of the resin holding member is held, the holding made the resin The member is cylindrical, and the resin holding member is attached by being fitted into a hole provided in the quartz support member, and the resin holding member attached to the quartz support member is The above The quartz support member vibrator-side for generating a ultrasonic wave in Gasonikku cleaning apparatus, the opposite side of Ri Do and the resin holding member, the projected area of the resin holding member as viewed from the vibrator side quartz A substrate holding jig which is arranged to be smaller than a support member .   The substrate holding jig according to claim 1, wherein the resin holding member is made of a fluororesin. A megasonic cleaning apparatus for cleaning a substrate, comprising at least the substrate holding jig according to claim 1 or 2 , wherein the substrate held in the cleaning tank by the substrate holding jig, A megasonic cleaning device for cleaning while applying ultrasonic waves generated by a vibrator.

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