JP2008004875A - Wafer edge face protective device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer edge protective device for processing two or more wafers efficiently while preventing processing failure, such as wafer peeling. <P>SOLUTION: By operating a pushing mechanism 43; a wafer pushing unit 25 and a wafer mounting unit 23 are approached, and two wafers W between the wafer pushing unit 25 and the wafer mounting unit 23 are pinched each by seal members 9, 33 so that two wafers W mounted on the wafer mounting unit 23 are put in a pushed state by the wafer pushing unit 25. In this way, processing failure, such as processing of the edge face of the wafer W by potassium hydroxide, and corroding of wax or the like which bonds the wafer W to a base member, by potassium hydroxide, can be prevented. In addition, if each wafer W is mounted on plural-wafer mounting plate 3, the edge face of two or more wafers W can be protected easily and thereby two or more wafers W are processed effectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer end surface protection device that protects a non-processed surface and an end surface of a wafer when a predetermined process is performed by immersing a wafer such as a silicon semiconductor or a compound semiconductor in a processing solution.

Conventionally, as this type of wafer processing, there is processing for reducing the thickness of the wafer (referred to as thinning or thinning processing). In this case, for example, a wax is first applied and melted on the base member, and then placed on the non-processed surface on which the circuit of the wafer or the like is formed facing downward. Then, by cooling the wafer and the base member, the wafer is fixed to the base member, and the wafer is stored together with the base member in a processing tank stored as an etching solution containing potassium hydroxide (KOH). Immerse in a wafer. As a result, the processing surface of the wafer is chemically polished to reduce the thickness of the wafer (see, for example, Patent Document 1).
JP 2003-347254 A

However, the conventional example having such a configuration has the following problems.
That is, in the conventional apparatus, since it is difficult to make the wax resistant to potassium hydroxide in the conventional wafer processing, the wax is dissolved in the etching solution, and the wafer is peeled off from the base member in the etching solution. Or a part of the peripheral edge portion of the wafer corresponding to the non-processed surface side is etched.

  In addition, the operation of attaching the wafer to the base member is complicated, and there is a problem that it takes a long time to start the etching process for a plurality of wafers.

  The present invention has been made in view of such circumstances, and structurally protects an end face of a wafer, and enables protection from a plurality of wafers in a lump so that the wafer can be protected from the base member. It is an object of the present invention to provide a wafer edge protection device that can prevent processing defects such as wafer peeling and can efficiently process a plurality of wafers.

In order to achieve such an object, the present invention has the following configuration.
That is, the invention according to claim 1 is a wafer end surface protection device for protecting a non-processed surface and an end surface of a wafer when a wafer is immersed in a processing solution to process the processed surface of the wafer. A plurality of wafer mounting plates for mounting the first wafer with the processing surface facing the mounting surface, and a processing circle formed on the wafer mounting plate and having a substantially circular shape among the processing surfaces of the first wafer A first opening that is disposed on the mounting surface of the corresponding wafer opening plate and the wafer mounting plate and includes an end surface of the first wafer and prevents a portion of the first wafer excluding the processing circle from touching the processing liquid. A wafer mounting portion having a sealing member, a wafer mounted on the non-processed surface of the first wafer and a second wafer mounted thereon, the wafer having substantially the same shape as the first wafer and the second wafer. Press the second wafer with the protective plate and the pressing surface facing the processing surface of the second wafer A plurality of wafer pressing plates, an opening corresponding to a processing circle having a substantially circular shape among the processing surfaces of the second wafer formed on the pressing plate, and a pressing surface of the pressing plate, A wafer pressing portion having a second seal member including an end surface of the second wafer and preventing a portion of the second wafer excluding the processing circle from touching the processing liquid; and a mounting surface of the wafer mounting portion And a pressing mechanism for bringing the pressing surface of the wafer pressing plate close to each other.

  [Operation / Effect] According to the invention described in claim 1, the first wafer is placed with the processing surface facing the mounting surface of the wafer mounting plate, and the non-processing surface of the first wafer is placed. The wafer protection plate is placed on the second wafer, and the second wafer is placed with the non-processing surface facing the wafer protection plate, and then the pressing mechanism is operated. Thereby, the mounting surface of the wafer mounting portion and the pressing surface of the wafer pressing plate are brought close to each other, and the two wafers sandwiched between the pressing surface and the mounting surface are respectively the first seal member and the second seal. The two wafers sandwiched between the members and placed on the wafer placement unit are pressed by the wafer pressing unit. At this time, the processing liquid is made to touch the processing circle of the wafer through the opening, but the processing liquid is not touched to other portions. Therefore, it is possible to prevent processing defects such as processing of the end surface of the wafer with the processing liquid or erosion of the wax or the like adhering the wafer to the base member by the processing liquid. Further, if the wafers are placed on the plurality of wafer placement plates, respectively, the end faces of the plurality of wafers can be easily protected, so that the plurality of wafers can be processed efficiently.

  In the present invention, the wafer mounting portion is disposed apart from a wafer mounting plate located at an end of the plurality of wafer mounting plates, and is connected to all the wafer mounting plates. The wafer pressing portion is spaced apart from a wafer pressing plate located at an end of the plurality of wafer pressing plates, and is disposed outward from the ceiling plate, and is connected to all the wafer pressing plates. Preferably, the pressing mechanism includes a pressing bolt screwed to the ceiling surface and having an end connected to the upper plate. When the pressing bolt is rotated, the upper plate and the ceiling plate can be brought close to or separated from each other, so that the wafer mounting plate and the wafer pressing plate can be brought close to or separated from each other. Therefore, a plurality of wafers placed on the wafer placement unit can be pressed by a simple operation of rotating the pressing bolt.

  Also, in the present invention, the first seal member is disposed along the opening of the wafer mounting plate, and contacts an inner seal member that contacts the processing surface side of the first wafer. It is preferable to include an outer seal member disposed outward from the end surface. The inner sealing member can prevent the processing liquid from entering from the processing circle of the first wafer, and the outer sealing member can prevent the processing liquid from entering from the outer peripheral surface of the first wafer.

  Further, in the present invention, the second seal member is disposed along the opening of the wafer pressing plate and is in contact with the processing surface side of the second wafer, and the end surface of the second wafer. It is preferable to further include an outer seal member disposed outward. The inner sealing member can prevent the processing liquid from entering from the processing circle of the second wafer, and the outer sealing member can prevent the processing liquid from entering from the outer peripheral surface of the second wafer.

  In the present invention, the wafer mounting plate may move the first wafer, the second wafer, and the wafer protection plate in the horizontal direction along the outer diameters of the first wafer and the second wafer. It is preferable to provide a plurality of alignment pins to be regulated. Since the first wafer, the wafer protection plate, and the second wafer are stacked in this order on the wafer mounting plate, horizontal displacement is likely to occur. However, since a plurality of alignment pins are provided, the positional displacement is performed. Can be prevented, and the first and second wafers can be easily mounted.

  According to the wafer end surface protection device of the present invention, by operating the pressing mechanism, the mounting surface of the wafer mounting portion and the pressing surface of the wafer pressing plate are brought close to each other and sandwiched between the pressing surface and the mounting surface. The two wafers are sandwiched between the first seal member and the second seal member, respectively, and the two wafers placed on the wafer placement unit are pressed by the wafer pressing unit. At this time, the processing liquid is made to touch the processing circle of the wafer through the opening, but the processing liquid is not touched to other portions. Therefore, it is possible to prevent processing defects such as processing of the end surface of the wafer with the processing liquid or erosion of the wax or the like adhering the wafer to the base member by the processing liquid. Further, if the wafers are placed on the plurality of wafer placement plates, respectively, the end faces of the plurality of wafers can be easily protected, so that the plurality of wafers can be processed efficiently.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is an external perspective view showing a schematic configuration of a wafer end surface protection device according to an embodiment, and FIG. 2 is a longitudinal sectional view showing a main part of the wafer end surface protection device. FIG. 3 is an explanatory view showing a state where a wafer is set, and FIG. 4 is an explanatory view showing an operation when pressing the wafer.

  The wafer end surface protection device 1 protects the non-processed surface S1 and the end surface of the wafer W when the wafer W is immersed in a processing solution and thinned. As the treatment liquid, for example, an etching liquid containing potassium hydroxide is used, which is heated to a temperature of 70 ° C. and used. In the wafer W, a surface on which a circuit or the like is formed is a non-processed surface S1, and the opposite surface is a processed surface S2 to be etched. In the thinning process, for example, the wafer W is immersed in a potassium hydroxide solution heated to 70 ° C., and the thickness of the 200 mm diameter wafer W is reduced to 50 μm or less. The wafer end surface protection device 1 described below is made of a stainless steel plate or a fluororesin having resistance to high-temperature potassium hydroxide.

  The wafer mounting plate 3 has a square shape in plan view, and a mounting surface 5 on which the first wafer W1 is mounted in a horizontal posture with the processing surface S2 facing is formed on the upper surface thereof. A penetrating opening 7 is formed at the center of the wafer mounting plate 3. The diameter of the opening 7 is slightly smaller than the diameter of the first wafer W1 and has a size corresponding to a processing circle C described later.

  On the mounting surface 5 of the wafer mounting plate 3, a seal member 9 having an annular shape in plan view is disposed. The seal member 9 includes an inner seal member 11 erected along the opening 7 and an outer seal member 13 erected outside the end surface of the first wafer W1. A plurality of alignment pins 15 are provided outside the inner seal member 11 and inside the outer seal member 13. The alignment pins 15 are arranged along the outer shape of the first wafer W <b> 1. When the wafer W or the like is stacked on the mounting surface 5, movement in the horizontal direction is restricted.

  In addition, it is preferable that the said sealing member 9 is comprised with the material provided with tolerance to the potassium hydroxide which is an example of a process liquid. For example, polymer materials classified into perfluoroelastomer (having the same chemical structural formula as fluororesin) are preferable. Specifically, Kalrez (registered trademark: DuPont Dow Elastomer Co., Ltd.), Perflo (registered trademark: Daikin Industries), EPDM (ethylene propylene rubber) and the like are exemplified.

  For example, five wafer mounting plates 3 are provided, and each wafer mounting plate 3 is disposed with a predetermined distance between them. Four support plates 17 are attached to each wafer placement plate 3. Each support plate 17 is attached to only two opposite sides of the four sides of each wafer mounting plate 3 so as not to interfere with loading and unloading of the wafer W and the like. A ceiling plate 19 is attached to the uppermost portion of the four support plates 17, and a bottom plate 21 is attached to the lowermost portion.

  The five wafer mounting plates 3, the seal member 9, the alignment pins 15, the four support plates 17, the ceiling plate 19, and the bottom plate 21 constitute a wafer mounting portion 23. Yes.

A wafer pressing portion 25 is disposed inside the wafer placement portion 23 so as to be movable up and down.
The wafer pressing unit 25 includes a wafer pressing plate 27. The wafer pressing plate 27 has a square shape in a plan view, and a lower surface of the wafer pressing plate 27 presses the processing surface S2 of the second wafer W2, and the pressing surface faces the surface facing the mounting surface 5 of the wafer mounting plate 3. 29 is formed. Five wafer pressing plates 27 are provided above the above-described wafer mounting plates 3 so that the mounting surfaces 5 and the pressing surfaces 29 face each other. A through opening 31 is formed in the center of the wafer pressing plate 27. The diameter of the opening 31 is slightly smaller than the diameter of the second wafer W2, and corresponds to a processing circle C described later.

  A seal member 33 is disposed on the pressing surface 29 of the wafer pressing plate 27. The seal member 33 includes an inner seal member 35 and an outer seal member 37. These materials and sizes are the same as those of the sealing member 9 described above.

  Four support plates 39 are attached to each wafer pressing plate 27. Each support plate 39 is attached to only two opposite sides of the four sides of each wafer pressing plate 27 and is attached to the side where the support plate 17 that supports the wafer placement plate 3 is not provided. An upper plate 41 is attached to the uppermost part of the four support plates 39.

  A pressing mechanism 43 is disposed on the ceiling plate 19 of the wafer placement unit 23 and the upper plate 41 of the wafer pressing unit 25.

  A penetrating female screw portion 45 is disposed in the central portion of the ceiling plate 19, and a through hole 47 is formed in the central portion of the upper plate 41. A press bolt 49 is screwed into the female screw portion 45, and a set screw 51 that is loosely inserted into the through hole 47 is attached to a tip portion (lower end portion) thereof. Since the set screw 51 is loosely inserted into the through hole 47, the set screw 51 rotates idly with respect to the upper plate 41 even when the pressing bolt 49 rotates.

  In order to set the wafer W, first, the pressing bolt 49 is rotated and pulled up from the ceiling plate 19. Then, the upper plate 41 of the wafer pressing unit 25 is pulled up to the ceiling plate 19 side, and each wafer pressing plate 27 is brought into a “loading / unloading position” separated from the wafer mounting plate 3. In this state, as shown in FIG. 3, the first wafer W1 is placed with the processing surface S2 of the wafer W facing the placement surface 5, and the wafer protection plate 53 is placed thereon. . The wafer protection plate 53 is for preventing a circuit or the like formed on the non-processing surface S1 of the first wafer W1 from being damaged by sliding between the wafers W. The material is preferably softer than the first wafer W1 and less likely to generate particles, and examples thereof include a fluororesin sheet and a polyimide sheet. Then, the second wafer W2 is placed thereon with the processing surface S2 facing the wafer protection plate 53 side. In this manner, two wafers W and one wafer protection plate 53 are stacked and placed on each wafer placement plate 3. At this time, the horizontal positions of the first and second wafers W1 and W2 and the wafer protection member 53 are regulated by the alignment pins 15, so that they can be accurately aligned without shifting.

  Next, as shown in FIG. 4, the pressing bolt 49 is rotated and screwed into the ceiling plate 19. As a result, the wafer pressing plate 27 is lowered toward the mounting surface 5 of the wafer mounting plate 3 to be a “processing position”. In this processing position, the inner sealing members 11 and 35 and the outer sealing members 13 and 37 include the end faces of the first and second wafers W1 and W2, and the processing circle C of the first and second wafers W1 and W2. The part except for is prevented from touching the processing liquid.

  After setting 10 wafers W as described above, the wafer end face protection device 1 is immersed in a potassium hydroxide solution heated to a high temperature. Then, the potassium hydroxide solution enters from the openings 7 and 31, and only the processing circle C of the processing surface S2 of the wafer W is etched. And after predetermined time passes, the wafer end surface protection apparatus 1 is pulled up from a potassium hydroxide solution, and a rinse process is performed with a pure water. Thereafter, the pressing bolt 49 is rotated to move to the “loading / unloading position”, and then ten wafers W are unloaded. Although each wafer W is very thinned by the thinning process, the peripheral portion of the wafer W excluding the processing circle C of the wafer W is maintained at its original thickness. Therefore, it is possible to prevent the wafer W from being damaged by handling or the like.

  According to this embodiment, by operating the pressing mechanism 43, the wafer pressing unit 25 and the wafer mounting unit 23 are brought close to each other, and the two wafers W sandwiched between the wafer pressing unit 25 and the wafer mounting unit 23. Are sandwiched between the seal members 9 and 33, and the two wafers W placed on the wafer placement unit 23 are pressed by the wafer pressing unit 25. At this time, the processing circle C of the wafer is contacted with the potassium hydroxide solution through the openings 7 and 31, but the other portions are sealed so as not to touch the potassium hydroxide solution. Accordingly, it is possible to prevent processing defects such as the end face of the wafer W being treated with the potassium hydroxide solution, or the wax or the like adhering the wafer W to the base member being eroded by the potassium hydroxide solution. In addition, since the wafers W are respectively mounted on the plurality of wafer mounting plates 3, the end surfaces of the plurality of wafers W can be easily protected, so that the plurality of wafers W can be processed efficiently.

  In addition, since the pressing mechanism 43 is provided, the plurality of wafers W can be pressed by a simple operation of screwing the pressing bolt 49.

  Next, a modification of the present invention will be described with reference to FIG. FIG. 5 is a longitudinal sectional view showing a main part of the wafer end surface protection device.

  The wafer end surface protection device 1A is different from the wafer end surface protection device 1 described above in the pressing mechanism 43.

  Specifically, the pressing mechanism 43 </ b> A includes a compression coil spring 55 disposed between the wafer mounting plate 3 and the wafer pressing plate 27 and a pressing lever 57 disposed on the ceiling plate 19. The compression coil spring 55 urges the wafer mounting plate 3 and the wafer pressing plate 27 in a direction away from each other. The pressing lever 57 has a fulcrum P in a through hole 59 formed in the central portion of the ceiling plate 19, a pressing piece 61 disposed between the ceiling plate 19 and the upper plate 41, and a tip portion of the pressing lever 57. Is provided with a locking piece 63. The ceiling plate 19 is provided with a restricting portion 65 that engages with the locking piece 63 and restricts the return of the pressing lever 57.

  In the above configuration, after placing the wafer W or the like without operating the pressing lever 57, the pressing lever 57 is operated to lock the locking piece 63 to the restricting portion 65. Then, the compression coil spring 55 is contracted, and the wafer W and the like are sealed. According to this modification, the wafer W or the like can be sealed simply by operating the pressing lever 57, and sealing can be performed in a short time.

  The present invention is not limited to the above embodiment, and can be modified as follows.

  (1) In the above description, the example in which the five wafer mounting plates 3 and the five wafer pressing plates 27 are provided has been described. However, the configuration may be less than five or six or more.

  (2) In the configuration described above, the alignment pins 15 are provided on the wafer mounting plate 3. However, if the wafer W and the wafer protection plate 53 can be accurately positioned and mounted, the alignment pins 15 need not be provided. Absent.

  (3) In the above-described embodiment, the inner seal member 11 (35) and the outer seal member 13 (37) are configured separately, but they may be integrated.

  (4) In the above-described embodiments, the thinning process of the wafer W using a solution containing potassium hydroxide as the processing liquid has been described. However, the present invention is, for example, a wafer made of hydrofluoric acid, sulfuric acid, aqua regia, etc. Even the processing of W can be applied.

It is an external appearance perspective view which shows schematic structure of the wafer end surface protection apparatus which concerns on an Example. It is a longitudinal cross-sectional view which shows the principal part of a wafer end surface protection apparatus. It is explanatory drawing which shows the state which sets a wafer. It is explanatory drawing which shows the operation | movement at the time of pressing a wafer. It is a longitudinal cross-sectional view which shows the principal part of the wafer end surface protection apparatus which concerns on a modification.

Explanation of symbols

W ... Wafer W1 ... First wafer W2 ... Second wafer S1 ... Non-processed surface S2 ... Processed surface 1 ... Wafer end face protection device 3 ... Wafer mounting plate 5 ... Mounting surface 7, 31 ... Opening 9,33 ... Seal member 11, 35 ... Inner seal member 13, 37 ... Outer seal member 19 ... Ceiling plate 23 ... Wafer mounting portion 25 ... Wafer pressing portion 27 ... Wafer pressing plate 29 ... Pressing surface 41 ... Upper plate 43 ... Pressing mechanism 49 … Pressing bolt 53… Wafer protection plate

Claims (5)

In the wafer end surface protection device that protects the non-processed surface and the end surface of the wafer when the wafer is immersed in the processing liquid to process the processed surface of the wafer,
A plurality of wafer mounting plates for mounting the first wafer with the processing surface of the first wafer facing the mounting surface, and a substantially circular shape of the processing surfaces of the first wafer formed on the wafer mounting plate. An opening corresponding to a processing circle exhibiting the above and a mounting surface of the wafer mounting plate are disposed on the mounting surface of the wafer mounting plate, and the portion excluding the processing circle of the first wafer touches the processing liquid. A wafer mounting portion having a first seal member for preventing
A wafer protection plate mounted on the non-processed surface of the first wafer and mounting the second wafer; a wafer protection plate having substantially the same shape as the first wafer and the second wafer;
A plurality of wafer pressing plates for pressing the second wafer with the pressing surface facing the processing surface side of the second wafer, and the pressing plate are formed in a substantially circular shape among the processing surfaces of the second wafer. A second opening disposed on the pressing surface of the pressing plate corresponding to a processing circle and the pressing plate, including an end surface of the second wafer, and prevents a portion of the second wafer excluding the processing circle from touching the processing liquid. A wafer pressing portion having a sealing member of
A pressing mechanism for bringing the mounting surface of the wafer mounting portion and the pressing surface of the wafer pressing plate close to each other;
A wafer end face protection device comprising: The wafer end surface protection device according to claim 1,
The wafer mounting unit is disposed apart from a wafer mounting plate located at an end of a plurality of wafer mounting plates, and includes a ceiling plate connected to all the wafer mounting plates.
The wafer pressing portion is spaced apart from a wafer pressing plate located at an end of the plurality of wafer pressing plates, and is disposed outward from the ceiling plate and is connected to all the wafer pressing plates. With a plate,
The wafer end surface protection device according to claim 1, wherein the pressing mechanism includes a pressing bolt screwed into the ceiling surface and having an end connected to the upper plate. The wafer end surface protection device according to claim 1 or 2,
The first seal member is disposed along the opening of the wafer mounting plate, and is disposed outside the end surface of the first wafer and an inner seal member that contacts the processing surface side of the first wafer. A wafer end surface protection device comprising: an outer seal member provided. In the wafer end surface protection device according to any one of claims 1 to 3,
The second seal member is disposed along the opening of the wafer pressing plate, and is disposed outside the end surface of the second wafer and an inner seal member that contacts the processing surface side of the second wafer. And a wafer end face protection device, comprising: In the wafer end surface protection device according to any one of claims 1 to 4,
The wafer mounting plate has a plurality of positions for restricting horizontal movement of the first wafer, the second wafer, and the wafer protection plate along the outer diameters of the first wafer and the second wafer. A wafer end face protection device comprising an alignment pin.

Images