JP6026869B2 - Workpiece mounting tray, wafer heat treatment tray using the same, and method for manufacturing workpiece mounting tray - Google Patents

Description

  The present invention relates to a workpiece mounting tray, a wafer heat treatment tray using the workpiece mounting tray, and a method for manufacturing the workpiece mounting tray.

  Conventionally, when heat-treating a workpiece such as a silicon wafer, it is known to use a tray made of ceramic having high heat resistance as a tray for individually placing the workpiece.

  For example, Patent Document 1 discloses a boat tray for wafer heat treatment in which a plurality of support columns made of ceramic are erected on the outer periphery of the boat tray.

JP 2008-21824

  However, in the tray described in Patent Document 1, when the support supporting the workpiece is made of ceramic, the ceramic molded body to be the support can be obtained by producing and firing by a powder extrusion molding method or a powder press molding method. If the fired struts are warped due to differences in the powder packing density and the degree of drying of the compact in the drying process, the mounting surface of the struts on which the work is placed to obtain flatness is obtained. Need to be polished. And the area of the workpiece mounting surface of the post after polishing becomes larger than the original area, and the defective part of the heat treatment of the workpiece supported by the column becomes wider by the amount of the wider workpiece mounting surface, and the yield There was a risk of lowering.

  The present invention has been devised to solve the above-described problems, and is a workpiece mounting tray capable of suppressing a decrease in workpiece yield, a wafer heat treatment tray, and a workpiece mounting tray using the same. An object of the present invention is to provide a manufacturing method.

The workpiece mounting tray of the present invention is a workpiece mounting tray that includes a bottom plate and a columnar support member provided on the bottom plate, and holds the workpiece by the support member, and the bottom plate and the support member Doo is Ri name than the ceramic, the support member is characterized in that together with formed by laminating a plurality of plate-like bodies, do not have a gap that communicates the outside between the plate-like body.

  The wafer heat-treating tray according to the present invention comprises the workpiece mounting tray having the above-described structure, and is used for heat-treating the work as a wafer.

According to the workpiece mounting tray of the present invention, since the support member that supports the workpiece is formed by laminating a plurality of plate-like bodies, the workpiece mounting tray has high heat resistance and suppresses warping of the support member. Can be a tray. Moreover, according to the workpiece mounting tray of the present invention, since the support member does not have a gap communicating with the outside between the plate-like bodies, even if the temperature rise and the temperature fall are repeated, The occurrence of peeling can be suppressed.

  In addition, the wafer heat treatment tray of the present invention comprises the workpiece mounting tray having the above-described configuration, and is used for heat treating the workpiece, which is a wafer, so that it is possible to suppress a decrease in wafer yield.

An example of the workpiece mounting tray of this embodiment is shown, (a) is a plan view of the workpiece mounting tray as viewed from the main surface side of the bottom plate, and (b) is a state in which a workpiece is mounted (a). It is sectional drawing of an AA 'line. The other example of the workpiece mounting tray of this embodiment is shown, (a) is a plan view of the workpiece mounting tray seen from the main surface side of the bottom plate, (b) in the state where the workpiece is mounted ( It is sectional drawing which expanded the CC 'line of a) partially. It is a top view of the square-shaped mounting surface which shows another example of the supporting member of the workpiece | work mounting tray of this embodiment. Sectional drawing which expanded the D section enclosed with the dotted line of FIG.1 (b), and the E section enclosed with the dotted line of FIG.2 (b) which show another example of the supporting member of the workpiece | work mounting tray of this embodiment. It is. It is sectional drawing which shows an example of the tray for wafer heat processing of this embodiment. It is a process flowchart which shows an example of the manufacturing method of the tray for workpiece | work mounting of this embodiment. An example of the manufacturing method of the workpiece | work mounting tray of this embodiment is shown, (a)-(f) is a perspective view of the processed goods in each process shown in FIG. 6, (g) is the ceramic green of (c). It is sectional drawing which expanded partially the process of forming the laminated body for support members from the laminated body of a sheet | seat.

  Embodiments of the present invention will be described below.

  An example of an embodiment of the workpiece mounting tray of the present invention will be described with reference to FIG.

  1A and 1B show an example of a workpiece placement tray according to the present embodiment. FIG. 1A is a plan view of the workpiece placement tray as viewed from the main surface side of the bottom plate, and FIG. 1B is a state where a workpiece is placed. It is sectional drawing of the AA 'line of (a) in FIG.

  A workpiece placement tray 1 shown in FIG. 1 includes a bottom plate 2 and a columnar support member 3 provided on the bottom plate 2, and is a workpiece placement tray 1 that holds a workpiece 15 by the support member 3. The bottom plate 2 and the support member 3 are made of ceramic, and the support member 3 is formed by laminating a plurality of plate-like bodies 4.

  The workpiece mounting tray 1 according to the present embodiment has high heat resistance and thermal conductivity because the bottom plate 2 and the support member 3 constituting the workpiece mounting tray 1 are made of ceramic. Can be used repeatedly. Furthermore, since the support member 3 is formed by laminating a plurality of plate-like bodies 4, the workpiece mounting tray 1 in which the warpage of the support member 3 in the height direction can be suppressed. Thereby, the positional accuracy of the mounting surface 3a of the support member 3 that supports the workpiece 15 can be increased, and when the workpiece 15 is used for heat treatment, the area that the support member 3 affects the heat treatment of the workpiece 15 increases. It is possible to suppress the occurrence of defects.

  Conventionally, when producing a large workpiece mounting tray with a support member standing upright with ceramic, the support member is formed by a powder extrusion molding method or a powder press molding method, and this molded body is dried. After that, the workpiece mounting tray is manufactured by bonding to a molded body to be a bottom plate individually manufactured by a powder press molding method or the like and firing them. However, the molded body serving as the support member is dried by causing a difference in packing density of the ceramic powder into the mold or by laying the rod-shaped body on a metal jig having a triangular cross-section during drying before firing. For this reason, there is a possibility that a difference in the degree of drying occurs and warping in the height direction occurs after firing. Further, after firing, the mounting surface of the support member is polished in order to increase the flatness of the workpiece mounting surface, but the area of the polished mounting surface is larger than the area of the original support member in the cross-sectional direction. .

  And if the workpiece is a product part of many pieces, the position of the workpiece supported by the mounting surface of the support member is adjusted to the disposal margin part, but the area of the mounting surface is increased because the mounting surface is the product There was concern that it would lead to a decrease in the yield of the work because it would extend to the sub-region.

  On the other hand, since the support member 3 of the workpiece mounting tray 1 of the present embodiment is a laminated body 3 ′ in which a plurality of plate-like bodies 4 are laminated, the density difference between the individual plate-like bodies 4 is in the width direction. Is difficult to appear, and the density difference in the width direction is small even in the laminated body 3 ′ in which the plate-like bodies 4 are laminated, and the occurrence of warpage in the height direction of the support member 3 after firing can be suppressed. Therefore, it is possible to suppress an increase in the area of the mounting surface 3a from the original area.

  As the ceramic that is the material of the work mounting tray 1 of the present embodiment, alumina, silicon nitride, aluminum nitride, zirconia, mullite, and a composite material thereof can be used.

  In FIG. 1, four support members 3 are arranged at equal intervals on the outer edge of the bottom plate 2, but depending on the size and thickness of the work 15, the position and number of the support members 3 may be appropriately selected. Good.

  The laminated body 3 ′ of the plate-like body 4 constituting the support member 3 can be produced by forming a ceramic green sheet to be the plate-like body 4 from a tape-like ceramic green sheet, laminating, joining, and firing later. .

  The bottom plate 2 can be produced in the same manner as the support member 3. When a heavy workpiece 15 is placed or when a plurality of workpiece placement trays 1 are stacked, the laminate may be formed by laminating a plurality of ceramic green sheets to give strength.

  As described above, since the surface of the support member 3 and the bottom surface 2 produced from the tape-shaped ceramic grease sheet has a small surface roughness, it is sufficient to polish the edge surface after firing, and the work placement with reduced manufacturing cost is possible. Tray 1 can be provided.

2A and 2B show another example of the workpiece mounting tray according to the present embodiment. FIG. 2A is a plan view of the workpiece mounting tray as viewed from the main surface side of the bottom plate, and FIG. It is sectional drawing which expanded the CC 'line | wire of (a) in the state which carried out partially.

  The workpiece mounting tray 11 of the present embodiment preferably has a convex portion 5 extending along the height direction on the side surface portion 3 b of the support member 3.

  The support member 3 of the workpiece mounting tray 11 shown in FIG. 2 has a substantially circular shape in which the cross-sectional shape repeats corrugated irregularities, and the convex portions 5 and the concave portions (valley portions) 6 are arranged in the height direction of the support member 3. It stretches along. As described above, when the side surface portion 3b of the support member 3 of the workpiece placement tray 11 has the convex portion 5 extending along the height direction of the support member 3, the workpiece placement tray 11 is used for heat treatment of the workpiece 15. Since the surface area of the support member 3 is large, the temperature of the support member 3 can follow the temperature rise and fall of the heat treatment without much delay, so that the support surface is supported by the mounting surface 3a. The occurrence of defects in the heat treatment of the workpiece 15 can be suppressed.

  FIG. 3 is a plan view of a rectangular placement surface showing another example of the support member of the workpiece placement tray of the present embodiment.

  The support member 3 of the workpiece mounting tray 11 shown in FIG. 2 is provided with seven convex portions 5 along the outer periphery having a substantially circular cross section, but the workpiece mounting tray 12 shown in FIG. The support member 3 has a substantially quadrangular cross-sectional shape and is provided with eight convex portions that repeat wave-shaped irregularities.

  As described above, the shape of the support member 3 may be either a circular shape or a square shape including a quadrangular cross-sectional shape, and the convex portion 5 to the side surface portion 3b includes one or more, and the unevenness is repeated. May be rectangular in addition to the wave shape.

  Furthermore, when the support member 3 is composed of a plurality of laminates 3 ′, it is preferable that the convex portions 5 are provided at least on the side surface portions 3b of the laminate 3 ′ close to the placement surface 3a of the workpiece 15, Thereby, at least the follow-up delay of the temperature of the heat treatment of the mounting surface 3a can be reduced.

  FIG. 4 shows another example of the support member for the workpiece mounting tray of the present embodiment, and enlarges the D portion surrounded by the dotted line in FIG. 1B and the E portion surrounded by the dotted line in FIG. FIG.

  The workpiece placement trays 1, 11, and 12 of this embodiment preferably do not have a gap 7 that communicates with the outside between the plate-like bodies 4 constituting the support member 3 (laminated body 3 ′).

  In FIG. 4, the D and E parts surrounded by dotted lines are indicated by dotted lines assuming that there is a gap 7 communicating with the outside at the joint of the plate-like body 4.

  In producing the workpiece mounting trays 1, 11, and 12 described above, the column member 3 can be a laminated body 3 ′ formed by laminating a plurality of plate-like bodies 4 from the viewpoint of the degree of freedom in design and the like. .

  However, in the laminated body 3 ′ formed by laminating a plurality of plate-like bodies 4, a gap 7 communicating with the outside may be generated between the respective plate-like bodies 4, and the gap 7 between the respective plate-like bodies 4. If the workpiece mounting tray in which the occurrence of this occurs is repeatedly used as a heat treatment tray, the plate-like body 4 may be peeled off from the gap 7 as the temperature rise and fall are repeated. In the workpiece mounting trays 1, 11, and 12 according to the present embodiment, since there is no gap 7 communicating with the outside at the joint of the plate-like body 4, the occurrence of peeling between the plate-like bodies 4 is suppressed. it can.

In the present embodiment, the fact that the gap 7 communicating with the outside is not provided between the plate-like bodies 4 of the support member 3 means that the size of the ceramic particles is reduced in the side surface portion 3 b of the joint between the plate-like bodies 4. Excluded are gaps 7 caused by level degranulation or voids, and depths d of 15 μm or less are not considered gaps 7.

  FIG. 5 is a cross-sectional view showing an example of a wafer heat treatment tray according to the present embodiment.

  A wafer heat treatment tray 21 according to the present embodiment shown in FIG. 5 uses the workpiece placement trays 1, 11, and 12 according to the present embodiment, and is used for heat treating the work 15 that is the wafer 22. .

  It is known that the semiconductor silicon wafer 22 is heat-treated in advance at a temperature of 1000 ° C. or higher in order to form a defect-free layer with a reduced oxygen concentration. A large number of product parts are produced from such a wafer 22. In order to suppress the occurrence of a heat treatment failure at a location that becomes the product part of the wafer 22, the mounting surface 3 a of the support member 3 that supports the wafer 22 is formed. It is important that the positional accuracy including the area is high.

  The workpiece mounting trays 1, 11, and 12 used for the wafer heat treatment tray 21 of the present embodiment have high heat resistance and heat conductivity because the bottom plate 2 and the support member 3 are made of ceramic, and the heat treatment temperature is 1000. Even when the temperature is higher than or equal to ° C., it can be used repeatedly.

  Furthermore, since the support member 3 is composed of a laminated body 3 ′ of a plurality of plate-like bodies 4, warpage in the height direction of the support member 3 can be suppressed, and the placement surface 3a regardless of whether or not the placement surface 3a is polished. The positional accuracy including the area can be improved. As a result, an increase in the area that affects the heat treatment of the wafer 22 can be suppressed, and the occurrence of defects can be suppressed.

  Further, when the side surface portion 3b of the support member 3 has the convex portion 5 extending along the height direction, the temperature of the support member 3 is not greatly delayed by the temperature increase and decrease of the heat treatment because the surface area of the support member 3 is large. In order to follow up, it is possible to suppress the occurrence of defects in the heat treatment of the wafer 22 supported by the mounting surface 3a of the support member 15, and it is possible to widen the region of the product portion in the wafer 22.

  Further, when the gap 7 communicating with the outside is not provided between the plate-like bodies 4 constituting the support member 3, the gap 7 is formed between the plate-like bodies 4 even if the temperature rise / fall by heat treatment is repeated. It is possible to suppress the occurrence of peeling.

  As described above, since the wafer heat treatment tray 21 of the present embodiment is composed of the workpiece placement trays 1, 11, and 12 of the present embodiment, it can be used repeatedly and the yield of the wafers 22 can be improved. Can contribute.

  Next, the manufacturing method of the workpiece | work mounting tray of this embodiment is demonstrated using FIG. 6 and FIG.

  FIG. 6 is a process flow diagram illustrating an example of a method for manufacturing a workpiece mounting tray according to the present embodiment. FIG. 7 illustrates an example of a method for manufacturing a workpiece mounting tray according to the present embodiment. (F) is a perspective view of the processed product in each step shown in FIG. 6, and (g) is a partially enlarged view of the step of forming a laminate for a support member from the laminate of ceramic green sheets in (f). FIG.

Note that FIG. 7 illustrates the columnar support member of the workpiece mounting tray, but the case where the support member is prismatic will also be described in conjunction with this drawing. 6 and 7 show a process of cutting out a part of the laminated body to produce a laminated body for the supporting member when producing the supporting member. In the case of producing a laminated body for a support member by laminating the state bodies, a part of the steps shown in FIGS. 6 and 7 can be omitted. In FIGS. 6 and 7, the production of the laminated body for the support member is illustrated by the wire method. However, the case of using the band saw will be described with reference to this drawing.

  In the manufacturing method of the workpiece mounting tray 1 of the present embodiment, first, as shown in FIG. 6A and FIG. 7A, there is a step of preparing a plurality of ceramic green sheets 8.

  The step of preparing a plurality of ceramic green sheets 8 is made into a tape shape by a doctor blade method using a known ceramic slurry or a roll compaction method using ceramic powder, and an arbitrary ceramic green sheet 8 is formed by punching or laser processing. Prepare multiple moldings.

  Next, as shown in FIG. 6B and FIG. 7B, the prepared plurality of ceramic green sheets 8 are laminated and pressed to produce a laminated body 9 '. When the ceramic green sheets 8 are laminated, a slurry composed of substantially the same components as the ceramic slurry used when preparing the ceramic green sheets 8 is applied to the laminated surface of the ceramic green sheets 8. After laminating 8, a laminated body 9 ′ is produced by applying pressure so that the entire bonding surface of the ceramic green sheet 8 is uniformly applied.

Next, as shown in F of FIG. 6 and FIG. 7 (f), a laminated body 9 for a support member is produced from a laminated body 9 ′ of ceramic green sheets 8.

  Here, the wire 17 provided in the wire cutting machine is used to rotate the ceramic green sheet 8 in the thickness t direction and move along the width w direction of the ceramic green sheet 8 (in the drawing, in the width w direction). The laminated body 9 of the ceramic green sheets 8 can be produced. The tool for producing the laminated body 9 'is not limited to the wire 17, but may be a band saw provided in a band saw machine.

  Furthermore, when the laminated body 9 has a quadrangular cross section, the portion of the ceramic green sheet 8 to be discarded can be minimized, regardless of whether the wire 17 or the band saw is used.

  The wire 17 is used for a common name wire saw, and is usually a loose abrasive in which a slurry containing diamond abrasive grains is blown by a nozzle onto an endless thread-like wire 17 made of carbon steel or the like, or a similar abrasive. Fixed abrasive grains provided with grains can be used.

  Band saw refers to the popular name band saw, which is usually an endless thin plate made of carbon steel, stainless steel, etc., and is equipped with fixed abrasive grains such as diamond. Can be selected and used as appropriate.

  Next, as shown in C of FIG. 6 and FIG. 7C, a ceramic green sheet 8 having a predetermined flat plate shape (circular in this figure) serving as a bottom plate is prepared. This ceramic green sheet 8 can be produced by using the same ceramic green sheet 8 as a supporting member and processing it into a predetermined shape by laser processing or press molding.

  In addition, when there is a weight such as when a work to be placed is large, the strength of the bottom plate is also required, and therefore the ceramic green sheet 8 serving as the bottom plate can also be a laminate.

  Next, as shown in FIG. 6D and FIG. 7 (d), a plurality of laminated bodies 9 of ceramic green sheets 8 serving as support members are placed on a main surface of a flat ceramic green sheet 8 serving as a bottom plate. The molded body 10 is produced by placing it at the position, pressurizing and joining. The ceramic green sheets 8 are preferably made of the same material in order to match the shrinkage ratio when the molded body 10 is fired. A tape-shaped ceramic green sheet 8 is formed on at least one of the laminated ceramic green sheets 8. The molded body 10 can be produced by applying substantially the same slurry as the ceramic slurry used for molding to the joint surfaces, laminating them, and then applying pressure.

  Next, as shown to E of FIG. 6, the molded object 10 obtained at the said process is baked. The molded body 10 is fired by a known tunnel-type continuous furnace, batch-type furnace, or the like, but if it is an alumina ceramic, it may be fired at a maximum temperature of about 1400 to 1600 ° C. Thereby, the workpiece mounting trays 1 and 11 of the present embodiment shown in FIG.

Thus, according to the manufacturing method of the workpiece mounting trays 1 and 11 of the present embodiment, the bottom plate 2 and the support member 3 are made of ceramic, and the support member 3 is formed by laminating a plurality of plate-like bodies 4. The workpiece mounting trays 1 and 11 can be easily manufactured.

  When the laminate of the support member 3 is obtained using the wire 17 or the band saw, the wire 17 or the band saw rotates in the thickness t direction of the laminate 9 of the ceramic green sheet 8 and the width w direction. The workpiece mounting trays 1 and 11 in which the convex portions 5 are formed on the side surface portion 3b of the support member 3 can be easily manufactured.

  At the same time, when the laminate 9 serving as the support member 3 is produced from the laminate 9 ′ of the ceramic green sheets 8, there are gaps 7 communicating with the outside between the plurality of plate-like bodies 4 constituting the support member 3. It is possible to easily produce the workpiece loading trays 1 and 11 that are not present.

  Next, adjustment of the height of the convex portion 5 extending along the height direction on the side surface portion 3b of the support member 3 of the workpiece mounting trays 1 and 11 will be described with reference to FIGS. 7 (f) and 7 (g). To do.

  FIG. 7G shows the laminate 9 of the ceramic green sheets 8 by cutting the laminate 9 ′ of the ceramic green sheets 8 of FIG. To do.

  In this process, the laminated body 9 ′, which is a workpiece, is placed on the processing table 18 and cut by hitting the laminated body 9 ′ with a wire 17 or a band saw, but the lower part of the processing table 18 through which the wire 17 or the band saw passes. Is provided with a deflection width regulating member 19 for regulating the deflection width r in the width w direction. Thereby, the height of the convex part 5 extended along the height direction of the laminated body 9 for support members can be adjusted. For example, by increasing the setting of the swing width r, the height of the convex portion 5 extending in the thickness t direction of the ceramic green sheet 8 can be increased.

  In addition, when the height of the convex portion 5 is set more strictly, and when the height of the convex portion 5 is lowered, if the wire 17 is a wire 17, the height of the abrasive grains of the fixed abrasive grains is small. In the case of a band saw, it is preferable to use a continuous blade to which abrasive grains are continuously fixed.

  Thus, in the manufacturing process of the laminated body 9 which becomes the support member 3, the height 17 is formed on the side surface portion 3a of the support member 3 by regulating the deflection width r in the width w direction of the ceramic green sheet 8 of the wire 17 or the band saw. The height of the convex portion 5 extending along the direction can be easily adjusted.

1, 11, 12: Workpiece mounting tray 2: Bottom plate, 2a: Main surface 3: Support member, 3a: Mounting surface, 3b: Side surface portion, 3 ': Laminated body 4: Plate-like body 5: Convex portion 7 : Clearance 8: Ceramic green sheet 9, 9 ': Laminate
10: Molded body
15: Work
17: Wire
19: Swing width regulating member
21: Tray for wafer heat treatment
22: Wafer

Claims (3)

A bottom plate, and a columnar support member provided on the bottom plate, the support member a workpiece mounting tray for holding a workpiece, the Ri and the bottom plate and the support member the name of ceramic, the support member Is a tray for laminating a plurality of plates, and does not have a gap communicating with the outside between the plates.   The workpiece mounting tray according to claim 1, wherein a convex portion extending along a height direction is provided on a side surface portion of the support member. A wafer heat treatment tray comprising the work mounting tray according to claim 1 or 2 and used for heat treating the work as a wafer.

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