JP2006224194A - Work carrier, its control method and manufacturing method of wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a work carrier capable of detecting peeling of a coating part of the work carrier, its control method and a manufacturing method of a wafer. <P>SOLUTION: This work carrier having the coating part provided by applying coating on an inner surface part of a work holding hole is devised so that the coating part emits fluorescence. It is favorable that the coating part contains a fluorescence material or is coated with it and that a material of the coating part is a material of lower hardness than that of a work. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a work carrier used when lapping a flat plate work such as a semiconductor silicon single crystal wafer (hereinafter sometimes simply referred to as a wafer or a silicon wafer), a management method thereof, and a wafer manufacturing method. It is.

  Conventionally, in general, a method for manufacturing a semiconductor silicon single crystal wafer includes a slicing step of slicing a single crystal rod manufactured by a single crystal manufacturing apparatus to obtain a thin disk-shaped wafer, and a cracking of the wafer obtained in the slicing step. In order to prevent chipping, the chamfering process of chamfering the outer peripheral edge portion, the lapping process of lapping the chamfered wafer and flattening it, and the etching process of removing chamfering and processing strain remaining on the surface of the lapped wafer are performed. And a polishing process for finishing the surface of the etched wafer in a mirror shape, and a cleaning process for cleaning the polished wafer.

  By the way, the purpose of the lapping process is to obtain the required shape accuracy such as flatness and parallelism at the same time as aligning the sliced wafer to a predetermined thickness. In general, it is known that the wafer after the lapping process has the best shape accuracy, and it is said that the shape of the final wafer is determined, and the shape accuracy in the lapping process is extremely important.

  In addition, as a lapping technique, a combination of three movements, a rotation movement of a concentric circular surface plate, a revolving movement of a disk-shaped wrapping carrier with respect to the main body of the apparatus, and a rotation movement of a disk-shaped wrapping carrier, is conventionally used. There is known a lapping apparatus that applies a relative motion to a workpiece to perform lap. This wrapping apparatus has a configuration as shown in FIGS.

  FIG. 3 is an exploded explanatory view of the wrapping apparatus, FIG. 4 is a sectional explanatory view of the wrapping apparatus, and FIG. 5 is a top explanatory view showing a state in which the upper surface plate of the wrapping apparatus is removed.

  3 to 5, the wrapping device 22 has a lower surface plate 24 and an upper surface plate 26 provided to face each other in the vertical direction. The lower surface plate 24 and / or the upper surface plate 26 are rotated by driving means (not shown).

  The lower surface plate 24 has a sun gear 28 on the upper surface of the central portion thereof, and an annular internal gear 30 is provided adjacent to the peripheral portion thereof.

  Reference numeral 32 denotes a disc-shaped wrapping carrier, and a gear portion that meshes with the sun gear 28 and the internal gear 30 is formed on the outer peripheral portion thereof, thus forming a gear structure as a whole. A plurality of work holding holes 34 are formed in the carrier 32. A workpiece W such as a wafer to be wrapped is disposed in the workpiece holding hole 34.

  A wrapping carrier 32 is placed between the upper and lower surface plates 26, 24, and a gear outside the wrapping carrier 32 is meshed between a sun gear 28 located in the center of the lower surface plate 24 and an internal gear 30 outside the lower surface plate 24. Then, the wrapping carrier 32 performs a planetary motion between the upper and lower surface plates 26 and 24 that rotate while lowering the upper surface plate 26. The work W is accommodated in a work holding hole 34 opened in the wrapping carrier 32, and the wrapping carrier 32 is given a rotation and revolving motion.

  In order to perform the lapping operation, a through hole provided in the upper surface plate 26 from a nozzle 36 with a turbid liquid A such as slurry, which is a slurry, such as aluminum oxide or silicon carbide, and a liquid such as water containing a surfactant. The abrasive grains are fed between the workpiece W and the upper and lower surface plates 26 and 24 by flowing through the gap between the upper and lower surface plates 26 and 24 via 38, and the shape of the upper and lower surface plates 26 and 24 is transferred to the workpiece W.

  At present, a metal wrapping carrier is mainly used as the wrapping carrier 32 used for wrapping a semiconductor wafer. This is because a wrapping carrier such as a synthetic resin cannot be applied with sufficient pressure, and the wrapping carrier itself has a short life.

  The main method for producing a metal wrapping carrier is to punch a metal plate with a press to form work holding holes in accordance with the outer diameter and various work dimensions. The wrapping carrier formed in this way was affected by the hardness and the shape of the inner peripheral cross section of the work holding hole due to press punching.

Therefore, as shown in Patent Document 1, a synthetic resin thin film is provided on the periphery of the work holding hole, or a synthetic resin guide member is provided on the periphery of the work holding hole as shown in Patent Document 2. And a method of chamfering and smoothing the inner peripheral surface of the work holding hole as shown in Patent Document 3.
Japanese Utility Model Publication No.59-36368 JP-A-5-177537 JP-A-7-156062

  However, if the inner peripheral surface of the workpiece holding hole is chamfered and smooth as in the conventional case, a minute scratch may occur on the outer periphery of the workpiece due to the relationship between the lapping carrier and the hardness of the workpiece. It is preferable to coat a soft resin. However, since the strength of the synthetic resin part is inferior to that of the metal wrapping carrier itself, the synthetic resin part at the peripheral part of the work holding hole may be peeled off during use, and the wrapping carrier is replaced each time. There is a need. In particular, this coating part is generally formed thin, it is difficult to see that the coating part has been peeled off from the wrapping carrier, and if the workpiece is processed with the coating part peeled off, scratches will also occur on the outer periphery of the work Leads to the occurrence of defects. Therefore, it is important to thoroughly manage the wrapping carrier, particularly whether or not the coating portion is peeled off. The problem in the lapping process is also caused in the double-side polishing process.

  An object of this invention is to provide the work carrier which can make it easy to manage the presence or absence of peeling of the coating part of a work carrier, its management method, and the manufacturing method of a wafer in view of the said problem.

  The work carrier of the present invention is characterized in that in the work carrier having a coating portion provided by coating the inner peripheral surface of the work holding hole, the coating portion emits fluorescence. That is, the work carrier is characterized in that the coating portion contains or is coated with a fluorescent agent. In this way, by causing the coating portion to emit fluorescent light, the operator can surely check the peeling of the coating portion visually.

  As the material of the coating portion provided on the inner peripheral surface of the work holding hole, a material having a lower hardness than the work hardness such as a wafer is used. Although not particularly limited, for example, a vinyl resin or other synthetic resin is used, and a silicone resin is particularly preferable.

  By using a material softer than the workpiece as the coating material, it is possible to prevent scratches on the outer periphery of the workpiece that may occur during lapping. In particular, since a vinyl-based resin or a silicone resin can be produced with an appropriate hardness, it is difficult for the outer periphery of the work to be scratched.

  The above-described coating of silicone resin or the like has a translucent color, and is particularly a material that is difficult to check for peeling of the coating portion. In the present invention, in a work carrier coated with such nearly transparent resin or the like, peeling of the coating portion can be surely found by containing or applying a fluorescent agent, and this is particularly effective.

  According to the work carrier management method of the present invention, a work is loaded into a plurality of work holding holes formed in the work carrier, and the lower surface plate and the upper surface plate are pressed and clamped between the lower surface plate and the upper surface plate. In a lapping process for lapping the work by rotating or a double-side polishing process for double-side polishing, the work carrier of the present invention is used as the work carrier, and then the work carrier is lapped or double-side polished. The work holding hole is irradiated with black light (invisible light such as ultraviolet light that emits visible light when it hits a fluorescent material), and the presence or absence of peeling of the coating portion is detected according to the state of fluorescence emission.

  By performing such a check operation, the work carrier can be easily managed, and it is possible to prevent the coating portion of the work holding hole from being missed.

  In the wafer manufacturing method of the present invention, a wafer is loaded into a plurality of workpiece holding holes formed in a workpiece carrier, and the lower surface plate and the upper surface plate are pressed and clamped, and the lower surface plate and / or the upper surface plate are rotated. In the wafer manufacturing method including a lapping step for lapping the wafer or a double-side polishing step for double-side polishing, the work carrier of the present invention described above is used as the work carrier.

  As described above, according to the present invention, the management of the work carrier is facilitated, the oversight of the peeling of the coating part of the work holding hole is prevented, and the defect of the outer periphery of the work caused by the peeling of the coating part is prevented. Can be prevented.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the illustrated examples are illustrative only, and various modifications can be made without departing from the technical idea of the present invention. . In the following description, a wrapping carrier will be described as a representative example of the work carrier of the present invention.

  FIG. 1 is an enlarged plan view of a wrapping carrier according to the present invention, and FIG. 2 is a cross-sectional explanatory view showing a state in which the wrapping carrier of the present invention is mounted on a wrapping apparatus. 1 and 2, the same or similar members as those shown in FIGS. 3 to 5 are denoted by the same reference numerals.

  The basic structure and operation of the wrapping apparatus to which the wrapping carrier according to the present invention is mounted are the same as those of the conventional structure and operation shown in FIGS. 3 to 5 and will not be described in detail again. Explained.

  In the wrapping apparatus 22a to which the wrapping carrier 32a of the present invention is mounted, as shown in FIG. 2, the wrapping process of a workpiece, for example, a wafer W, is performed on a plurality of workpiece holding holes 34 formed in the wrapping carrier 32a. W is loaded, and the wafer W is pressed between the lower surface plate 24 and the upper surface plate 26 and processed.

  Here, the gears formed on the outer periphery of the wrapping carrier 32a are configured to mesh with the internal gear 30 and the sun gear 28, respectively, so that the wrapping carrier 32a itself revolves on the lower surface plate 24 while rotating. You can wrap both sides of the wafer W by exercising.

  The wrapping carrier is made by punching a metal plate such as carbon tool steel with a press. Further, in the wrapping carrier 32a of the present invention, as shown in FIGS. 1 and 2, the inner surface of the work holding hole 34 is formed. The coating portion 35 is provided by coating a synthetic resin containing a fluorescent agent or applying a fluorescent agent (fluorescent paint). If configured in this manner, the coating portion 35 of the work holding hole 34 emits fluorescence, so that the peeling of the coating portion 35 can be definitely confirmed.

  As a fluorescent agent contained in or applied to the coating portion 35 of the work holding hole 34 of the wrapping carrier 32a of the present invention, a material generally called a phosphor, for example, a material containing fluorescein or the like may be used, but it is applied to the coating portion. In some cases, it is preferable to use a paint prepared as a fluorescent paint.

  As a material for the coating portion 35 provided on the inner peripheral surface of the workpiece holding hole 34, a material having a hardness lower than the hardness of the workpiece W such as a wafer is used. Although not particularly limited, for example, a vinyl resin or other synthetic resin is used, and a silicone resin is particularly preferable.

  By using a coating material softer than the workpiece W, it is possible to prevent scratches on the outer periphery of the workpiece W that may occur during lapping. In particular, since a vinyl-based resin or a silicone resin can be manufactured with an appropriate hardness, the outer peripheral portion of the workpiece W is hardly scratched.

  Moreover, the coating of silicone resin or the like is a translucent color, and is a material that is particularly difficult to check for peeling of the coating. In the present invention, when coating a work resin holding hole of a wrapping carrier with such a synthetic resin that is nearly transparent, the synthetic resin or the like contains a fluorescent agent or is applied to the surface of the synthetic resin. It is.

  In the wrapping carrier of the present invention, the coating portion of the work holding hole emits fluorescence, so that the operator can surely check the peeling of the coating portion visually.

  According to the wrapping carrier management method of the present invention, a work is loaded into a plurality of work holding holes formed in the wrapping carrier, and the lower surface plate and the upper surface plate are pressed and sandwiched between the lower surface plate and / or the upper surface plate. In wrapping the workpiece by rotating, after the workpiece is lapped using the wrapping carrier of the present invention as the wrapping carrier, the workpiece holding hole of the wrapping carrier is irradiated with black light to emit fluorescence. By observing, the presence or absence of peeling of the coating portion is detected.

  By performing such confirmation work, management of the wrapping carrier is facilitated and it is possible to prevent the coating portion of the workpiece holding hole from being missed. In the above description, the example in which the work carrier of the present invention is used for lapping processing has been described, but it can be similarly applied to double-side polishing processing.

  The present invention will be described more specifically with reference to the following examples. However, it is needless to say that these examples are shown by way of illustration and should not be construed in a limited manner.

Example 1
The silicon wafer was processed using a lapping carrier as shown in FIG. 1 and a lapping apparatus as shown in FIG. The silicon wafer is loaded into a plurality of (coated) work holding holes provided in the wrapping carrier, and while the wrapping slurry is added, it is clamped between the lower surface plate and the upper surface plate, and the surface plate is rotated. Was processed.

  After performing the lapping process described above, the workpiece holding hole portion was irradiated with black light, and peeling of the coating portion was confirmed.

  Usually, slurry or the like is present in the work holding hole portion after lapping. In addition, since there is a wrapping carrier between the upper and lower surface plates, it is shaded by the upper surface plate, so it is difficult to confirm the coating portion. Therefore, conventionally, in order to confirm the peeling of the coating portion, the carrier has to be once taken out from the lapping apparatus and confirmed, so that the workability is poor.

  However, when the wrapping carrier of the present invention is used, the workpiece holding hole coating portion emits fluorescent light when irradiated with black light, and when the coating portion is not peeled off, the workpiece holding hole portion emits light in an annular shape. Therefore, confirmation could be carried out smoothly without taking out from the wrapping device.

  Using this lapping carrier, lapping was performed continuously. Even when the lapping carrier of the present invention is used, if the lapping process is repeated, the coating portion of the workpiece holding hole portion is peeled off.

  However, by irradiating with black light after completion of the lapping process, the part where the coating was peeled off did not emit fluorescence, and the peeling of the coating part became clear and could be detected.

  Further, the coating member that has been peeled off may adversely affect the lapping process thereafter. If the peeled coating member remains on the surface plate, when the next batch is processed, the peeled coating member enters between the wrapping carrier and the surface plate, which creates a gap between the carrier and the surface plate. There were occasions when I fell under the wrapping carrier. In addition, the wafers of all the batches were cracked or scratched, resulting in a large number of defects.

  With the wrapping carrier of the present invention, not only the state of the coating portion of the workpiece holding hole can be confirmed, but also the peeled coating member can always be found, and the surface plate cleaning (removal of the peeled coating member) becomes easy. .

  As described above, by using the work carrier of the present invention, it is possible to thoroughly manage the coating portion of the work holding hole, and the occurrence of scratches on the outer periphery of the wafer in lapping or double-side polishing can be greatly reduced.

  According to the present invention, it is possible to easily find the peeling of the coating portion of the work holding hole of the work carrier, and it is possible to always find the peeled coating member, facilitating the cleaning of the surface plate, and the outer periphery of the work such as a wafer. It is possible to greatly reduce the occurrence of scratches on the part and the occurrence of defective products (work cracks and scratches) due to the peeled coating member.

It is an enlarged plan view of a wrapping carrier according to the present invention. It is sectional explanatory drawing which shows the state which mounted | wore the wrapping apparatus with the wrapping carrier of this invention. It is decomposition | disassembly explanatory drawing of the conventional wrapping apparatus. It is sectional drawing of the conventional wrapping apparatus. It is upper surface explanatory drawing which shows the state which removed the upper surface plate of the conventional wrapping apparatus.

Explanation of symbols

22, 22a: Lapping device, 24: Lower surface plate, 26: Upper surface plate, 28: Sun gear, 30: Internal gear, 32: Conventional lapping carrier, 32a: Lapping carrier of the present invention, 34: Workpiece holding hole, 35: Coating portion, 36: nozzle, 38: through hole, A: turbid liquid, W: work, wafer.

Claims (6)

  A work carrier having a coating portion provided by coating the inner peripheral surface of the work holding hole, wherein the coating portion emits fluorescence.   The work carrier according to claim 1, wherein a fluorescent agent is contained or applied to the coating portion.   The work carrier according to claim 1 or 2, wherein the material of the coating portion is a material having a hardness lower than that of the work.   4. The work carrier according to claim 3, wherein the material of the coating portion is a silicone resin.   Wrapping to load a workpiece into a plurality of workpiece holding holes formed in the workpiece carrier, press and hold it between the lower surface plate and the upper surface plate, and wrap the workpiece by rotating the lower surface plate and / or the upper surface plate In the double-side polishing process for processing or double-side polishing, the work carrier is held by performing lapping or double-side polishing using the work carrier according to any one of claims 1 to 4 as the work carrier. A method for managing a work carrier, comprising: irradiating a coating portion of a hole with black light and detecting the presence or absence of peeling of the coating portion based on a state of fluorescence emission.   Wrapping is performed by loading a wafer into a plurality of work holding holes formed in a work carrier, pressing and holding the wafer between the lower surface plate and the upper surface plate, and wrapping the wafer by rotating the lower surface plate and / or the upper surface plate. In the manufacturing method of the wafer including the double-side polishing process of carrying out a process or double-side polishing, The work carrier of any one of Claims 1-4 is used as the said work carrier, The manufacturing method of the wafer characterized by the above-mentioned.

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