JP2008112804A - Wafer cassette - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer cassette for enabling automatic transfer or the like by controlling fluctuation among a plurality of semiconductor wafers. <P>SOLUTION: A wafer cassette 1 is soaked into liquid under the condition that a semiconductor wafer W accommodated through an input/output aperture 8 is set in the upright state by providing a pair of side plates 2 opposed with each other, bridging a bottom plate 5 and a ceiling plate 6 between the upper and lower end portions of the pair of side plates 2 to form a pair of openings, with the opening at the front surface serving as the input/output aperture 8 for the semiconductor wafer W, and also with the opening at the rear surface serving as a delivery opening 9. This wafer cassette is provided with a plurality of teeth 3 formed in a certain arrangement to the pair of side plates 2 to support both sides of the circumferential edge of the semiconductor wafer W and a holding groove 10 for holding the lower end of the circumferential edge of the semiconductor wafer W in the upright state. Moreover, a linear line passing the point where the pair of opposite teeth 3 and the semiconductor wafer W in the upright state are in the contact state is positioned at the lower location than the center of semiconductor wafer W and each holding groove 10 is formed in an asymmetrical cross-sectionally near V shape so that the lower end part of the circumferential edge of semiconductor wafer W in the upright state is in contact with a sloping surface having a large sloping angle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer cassette that is immersed in a liquid in a state where a stored semiconductor wafer is vertically erected.

  The thinly sliced semiconductor wafer is immersed in a liquid consisting of a wet securing solution in the water tank until the end of the edge chamfering process, the double-side polishing process, and the cleaning process is completed. Is immersed in a stored state. Although not shown, this type of wafer cassette includes a pair of opposing side plates, a front plate laid between the front end portions of the pair of side plates, and a back plate laid between the rear end portions of the pair of side plates, The open upper part is used as an inlet / outlet port for semiconductor wafers, and the narrow open lower part is used as a liquid outlet port, and a plurality of semiconductor wafers are placed in a horizontal row in a standing state. And immersed in a liquid (see Patent Document 1).

Each of the pair of side plates is bent and formed in a substantially rectangular shape that gradually narrows inward as it goes from the top to the bottom, and a plurality of teeth that contact and support both sides of the periphery of the semiconductor wafer are formed on the inner surface at a predetermined pitch in the front-rear direction. The teeth are bent and formed along the side of the periphery of the semiconductor wafer. The loading / unloading port is formed in a size that allows the semiconductor wafer to be loaded and unloaded, and the distribution port is formed in a size that the semiconductor wafer cannot be loaded / unloaded.
JP 2005-64530 A

  The conventional wafer cassette is configured as described above, and a plurality of teeth are simply arranged in parallel at a predetermined pitch on the inner surfaces of a pair of side plates. When the wafers are inclined in the alignment direction, there is a problem in that the intervals between the upper portions of the plurality of semiconductor wafers vary greatly, making it difficult to perform automatic conveyance after immersion.

  The present invention has been made in view of the above, and an object of the present invention is to provide a wafer cassette that suppresses variations among a plurality of semiconductor wafers and enables conveyance such as automatic conveyance.

In the present invention, in order to solve the above-described problem, a pair of side plates are opposed to each other with a space capable of accommodating a semiconductor wafer, and first and second opposing plates are respectively installed between both ends of the pair of side plates. A pair of opposed openings are formed, and one of the pair of openings is used as a loading / unloading opening that allows a semiconductor wafer to be taken in and out, and the other opening is formed to a size that prevents the semiconductor wafer from being taken in and out. As a circulation port for the liquid, it is immersed in the liquid in a state where a plurality of semiconductor wafers stored from the inlet / outlet are upright,
Each of the pair of side plates includes a plurality of teeth that support both sides of the peripheral edge of the semiconductor wafer, and a holding groove that holds a lower end of the peripheral edge of the semiconductor wafer, and the plurality of teeth contact the rising semiconductor wafer. A straight line passing through the point is positioned below the center of the semiconductor wafer, and the holding groove is formed in a substantially V-shaped asymmetric cross section so that the lower end of the peripheral edge of the semiconductor wafer standing on the inclined surface having a large inclination angle is brought into contact It is characterized by that.

  A first counter plate is installed between the lower ends of the pair of side plates as a bottom plate, a second counter plate is installed between the upper ends of the pair of side plates as a top plate, and the front is used as the entrance / exit. The back can be used as a distribution port.

Further, each of the pair of side plates is formed in a substantially rectangular shape in cross section, and a first counter plate is installed between the front end portions of the pair of side plates as a front plate, and a second counter plate is disposed between the rear end portions of the pair of side plates. A plate can be installed to form a back plate, the opened upper part can be used as a loading / unloading port, the opened lower part can be used as a circulation port, and a holding groove can be formed between the lower parts of the plurality of teeth.
In addition, a restricting plate that divides the other opening may be installed between the first and second opposing plates to form a circulation port, and a plurality of holding grooves may be formed side by side on the inner surface of the restricting plate.

  Here, the semiconductor wafer in the claims includes at least 150 mm type, 200 mm type, 300 mm type, 450 mm type and the like. This semiconductor wafer may stand upright when standing, but may stand up while tilting at a slight tilt angle, for example, 1 ° to 5 °. Further, the liquid includes at least a wet ensuring liquid, a cleaning liquid, and the like. There is no particular limitation on the number of restriction plates.

  The plurality of teeth and the holding groove are in a relationship in which the central portion in the thickness direction of the semiconductor wafer held by the plurality of teeth is shifted to the inclined surface side having a smaller inclination angle than the vertical line passing through the valley portion of the holding groove. Is preferred. Further, the wafer cassette is not particularly required to be transparent, translucent, or opaque, and may be of a type that is tilted sideways when immersed in a liquid, or not.

According to the present invention, when a semiconductor wafer is immersed in a liquid, each semiconductor wafer is erected vertically with the orientation of a plurality of semiconductor wafers in a horizontal row, and the wafer cassette is submerged in the liquid. The liquid flows in from the inlet / outlet of the cassette and the distribution port, and each semiconductor wafer can be immersed in the liquid.
At this time, the standing semiconductor wafer may be tilted by swinging in the alignment direction, but the lower end portion is not in contact with the gently inclined surface but the asymmetrically inclined surface having a substantially V-shaped holding groove. Since the wafer cassette is held, the wafer cassette is supported substantially vertically by the stationary wafer cassette.

  According to the present invention, a plurality of teeth formed on a pair of side plates and supporting both sides of the peripheral edge of the semiconductor wafer, and a holding groove for holding the lower end of the peripheral edge of the upstanding semiconductor wafer are provided. The semiconductor wafer has a straight line passing through the contact point with the semiconductor wafer positioned below the center of the semiconductor wafer, and the holding groove is formed in a substantially V-shaped asymmetric cross section so that the peripheral edge of the semiconductor wafer stands on the inclined surface having a large inclination angle. Since the lower ends are brought into contact with each other, there is an effect that it is possible to provide a wafer cassette that suppresses variations among a plurality of semiconductor wafers and enables transfer such as automatic transfer.

  In addition, if a distribution port is formed by laying a regulating plate that divides the other opening between the first and second opposing plates, the ejecting jig for taking out without causing the semiconductor wafer to fall off by the regulating plate Can be allowed to enter, contributing to automation of semiconductor manufacturing.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 10, a plurality of wafer cassettes 1 (for example, 13, 25, 26) are used in this embodiment. A pair of left and right side plates 2 facing each other with an interval capable of aligning and storing the semiconductor wafers W, a bottom plate 5 installed between the lower ends of the pair of side plates 2, and an upper end of the pair of side plates 2. A pair of openings facing each other in the front-rear direction is formed, and the front opening of the pair of openings is used as a loading / unloading opening 8 through which the semiconductor wafer W can be loaded and unloaded, and the back opening is a liquid. When it is immersed in the liquid in the water tank, it is tilted sideways and the front loading / unloading port 8 is directed upward so that a plurality of stored semiconductor wafers W are erected.

  As shown in FIG. 1 and FIG. 7 to FIG. 9, the semiconductor wafer W is of, for example, a 200 mm or 300 mm diameter sliced thinly and rounded, and the peripheral edge is rounded and chamfered. Until the polishing step and the cleaning step are completed, the substrate is immersed in a liquid stored in the water tank, for example, a wet securing liquid.

  As shown in FIGS. 1, 2, and 6, the pair of side plates 2 is provided with a pair of left and right teeth 3 that support both sides of the periphery of the semiconductor wafer W in a substantially horizontal point contact manner. A pair of teeth 3 are arranged in parallel in the vertical direction of the side plate 2 at a predetermined pitch, and each side plate 2 is formed in a substantially circular arc shape in cross section. A plurality of teeth 3 in each side plate 2 are formed in an alignment groove 4 having an inclined bottom surface between them, and each tooth 3 is formed in a substantially triangular shape having an elongated and tapered shape.

  A straight line SL passing through the contact point between the pair of teeth 3 and the standing semiconductor wafer W is located below the center Wc of the semiconductor wafer W as shown in FIG. However, it is easy to slide or swing in the thickness direction, in other words, the alignment direction of the plurality of semiconductor wafers W.

  Between the bottom plate 5 and the top plate 6, as shown in FIGS. 1, 2, 5, and 6, a pair of elongate regulating plates 7 that divide the opening on the back surface in the circumferential direction are arranged side by side and are installed vertically. A plurality of flow ports 9 through which the semiconductor wafer W cannot be taken in and out are formed by installing the pair of regulating plates 7. The plurality of flow ports 9 allow the liquid in the water tank to flow inside and outside the wafer cassette 1, It functions to allow the protrusion jig for taking out the wafer W to enter.

  Each regulating plate 7 is formed in a vertically long shape having a substantially arc-shaped cross section, and a plurality of holding grooves 10 corresponding to the pair of teeth 3 are formed side by side in the vertical direction of the inner surface. Functions to fit and hold the lower end of the peripheral edge of the semiconductor wafer W, in other words, the lower end of the peripheral edge of the semiconductor wafer W standing up.

  As shown in FIG. 8 and FIG. 9, the holding groove 10 is not a simple U-shaped section or a substantially V-shaped section, but a pair of inclined surfaces 10 a and 10 b are asymmetrical sectional V-shapes. The lower end of the peripheral edge of the semiconductor wafer W that stands up while tilting at a slight tilt angle makes point contact with the inclined surface 10a that is formed in an L shape and has a large tilt angle.

  The plurality of holding grooves 10 correspond in position to the pair of teeth 3, but the pair of teeth 3 and the plurality of holding grooves 10 are paired when the wafer cassette 1 is placed horizontally as shown in FIG. 8. The center portion CL in the thickness direction of the semiconductor wafer W held by the teeth 3 is slightly smaller in inclination angle than the vertical line PL passing through the trough portion 10c below the holding groove 10 and is shifted toward the steep inclined surface 10b side. A good positional relationship.

  The bottom plate 5 and the top plate 6 are formed in a substantially disc shape having a thickness slightly larger than the semiconductor wafer W, and a plurality of positioning tools 11 are integrally formed on the bottom plate 5 so as to draw a substantially Y-shaped plane. The recessed V-grooves of the plurality of positioning tools 11 are fitted and supported from above on the positioning pins of the processing apparatus for manufacturing semiconductors, whereby the wafer cassette 1 is positioned and fixed on the processing apparatus (FIGS. 1 and 2). 4).

  In the above, when the semiconductor wafer W is stored in the wafer cassette 1, the semiconductor wafer W is inserted into the loading / unloading port 8 of the wafer cassette 1 of FIG. The semiconductor wafer W can be stored in the wafer cassette 1 by fitting and holding the rear side of the periphery of the semiconductor wafer W (the lower end of the periphery when the semiconductor wafer W stands up) in each holding groove 10. By repeating this operation, a plurality of semiconductor wafers W can be aligned and stored in the wafer cassette 1 in a vertical row.

  When the semiconductor wafer W is immersed in the liquid in the water tank as shown in FIG. 10, the wafer cassette 1 shown in FIG. If the postures of a plurality of aligned semiconductor wafers W are changed to a horizontal row, each semiconductor wafer W is raised vertically, and the wafer cassette 1 is transported and submerged in a water tank. A liquid flows in from the circulation port 9, and each semiconductor wafer W can be immersed in the liquid.

  When the wafer cassette 1 is transported or settled, the standing semiconductor wafer W may be greatly tilted by shaking in the alignment direction due to vibration or liquid flow, but is supported vertically as the wafer cassette 1 is left standing. It will be. Explaining this point, the positional relationship between the pair of teeth 3 and the plurality of holding grooves 10 corresponding to these three is the thickness of the semiconductor wafer W held by the pair of teeth 3 when the wafer cassette 1 is placed horizontally. The center portion CL in the vertical direction is shifted to the inclined surface 10b side steeper than the vertical line PL passing through the valley portion 10c of each holding groove 10.

  Due to such a relationship, the semiconductor wafer W inclined in the alignment direction has its lower end naturally deviated from the steep inclined surface 10b of the holding groove 10 to the gentle inclined surface 10a (see the arrow in FIG. 8), and is in point contact and smoothly. Since the positioning is guided, the wafer cassette 1 is supported vertically as the wafer cassette 1 is left stationary.

  According to the above configuration, since the inclined surface 10a of the holding groove 10 exhibits a positioning function, the interval between the upper portions of the plurality of semiconductor wafers W may vary greatly, or the upper portions of adjacent semiconductor wafers W may contact each other. Absent. Therefore, it is possible to greatly improve the pitch accuracy when the semiconductor wafer W is vertically placed, and automatic conveyance after immersion is actually facilitated. Further, since the space between the plurality of teeth 3 in each side plate 2 is not a simple U-shaped groove, but is formed in an alignment groove 4 having an inclined bottom surface, a plurality of sheets are utilized by using the bottom surface inclined in the thickness direction of the side plate 2. The semiconductor wafers W can be aligned in an orderly manner.

  Furthermore, since the wafer cassette 1 is configured in a structure that can be used vertically and horizontally and a plurality of positioning tools 11 are disposed on the bottom plate 5, the versatility of the wafer cassette 1 can be improved, and the wafer cassette 1 can be simplified in a processing apparatus. Can be positioned and fixed.

  In the above-described embodiment, the wafer cassette 1 is injection-molded using a molding material such as PBT. However, the present invention is not limited to this, and may be an assembly type, for example. Further, an RFID tag of the RFID system may be attached to the wafer cassette 1 to contribute to automatic identification of the semiconductor wafer W.

  Further, both sides of the peripheral portion of the semiconductor wafer W may be supported by point contact between the pair of left and right teeth 3, but if the lower end of the peripheral portion of the standing semiconductor wafer W can be easily slid, the semiconductor wafer W You may support the peripheral part both sides by line contact. In addition, although a pair of restriction plates 7 are arranged side by side between the bottom plate 5 and the top plate 6 of the wafer cassette 1, the invention is not limited to this, and the restriction plates 7 can be increased or decreased as necessary. It is. For example, it is possible to use one restriction plate 7.

  Further, in the above embodiment, the front and rear opened wafer cassettes 1 are shown, but the present invention is not necessarily limited to this, and upper and lower opened wafer cassettes 1 may be used. In this case, a pair of left and right side plates 2 facing each other, a front plate constructed between the front end portions of the pair of side plates 2, and a back plate constructed between the rear end portions of the pair of side plates 2 are provided. The upper part of the opening is used as a loading / unloading port 8 for the semiconductor wafer W, and the pair of side plates 2 are bent in a substantially rectangular shape that gradually narrows inwardly from the upper side to the lower side. A plurality of teeth 3 that are positioned on the lower side and are in contact with and supported on the inner surface of each side plate 2 along both sides of the peripheral edge of the semiconductor wafer W are arranged in parallel at a predetermined pitch in the front-rear direction, and between the lower portions of the plurality of teeth 3 Can be a holding groove 10 having an asymmetric cross-section and a substantially V-shaped cross section.

It is a perspective explanatory view showing typically an embodiment of a wafer cassette concerning the present invention. It is front explanatory drawing which shows typically embodiment of the wafer cassette which concerns on this invention. It is a plane explanatory view showing typically an embodiment of a wafer cassette concerning the present invention. It is bottom explanatory drawing which shows typically embodiment of the wafer cassette which concerns on this invention. It is back explanatory drawing which shows typically embodiment of the wafer cassette which concerns on this invention. It is a section explanatory view showing typically an embodiment of a wafer cassette concerning the present invention. It is explanatory drawing which shows typically the accommodation state of the standing semiconductor wafer in embodiment of the wafer cassette which concerns on this invention. It is explanatory drawing which shows typically the relationship between the teeth in the embodiment of the wafer cassette which concerns on this invention, a holding groove, and the standing semiconductor wafer. It is explanatory drawing which shows typically the relationship between the holding groove | channel and the standing semiconductor wafer in embodiment of the wafer cassette which concerns on this invention. It is explanatory drawing which shows typically the alignment accommodation state of the several semiconductor wafer which stood up in embodiment of the wafer cassette which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer cassette 2 Side plate 3 Teeth 4 Alignment groove 5 Bottom plate 6 Top plate 7 Restriction plate 8 Inlet / outlet 9 Distribution port 10 Holding groove 10a Inclined surface 10b Inclined surface 10c Valley 11 Positioning tool CL Center part PL of semiconductor wafer thickness direction Vertical line SL passing through trough of holding groove Straight line W Semiconductor wafer Wc Center of semiconductor wafer

Claims (3)

A pair of side plates are opposed to each other with an interval capable of accommodating a semiconductor wafer, and first and second opposing plates are respectively installed between both ends of the pair of side plates to form a pair of opposed openings. One of the openings is used as a loading / unloading port where a semiconductor wafer can be taken in and out, and the other opening is formed into a size that prevents the semiconductor wafer from being taken in and out to serve as a liquid circulation port, and is stored from the loading / unloading port. A wafer cassette immersed in a liquid in a state where a plurality of semiconductor wafers are erected,
Each of the pair of side plates includes a plurality of teeth that support both sides of the peripheral edge of the semiconductor wafer and a holding groove that holds a lower end of the peripheral edge of the semiconductor wafer, and the contact between the plurality of teeth and the semiconductor wafer rising A straight line passing through the point is positioned below the center of the semiconductor wafer, and the holding groove is formed in a substantially V-shaped asymmetric cross section so that the lower end of the peripheral edge of the semiconductor wafer standing on the inclined surface having a large inclination angle is brought into contact A wafer cassette characterized by that.   A first counter plate is installed between the lower ends of the pair of side plates as a bottom plate, a second counter plate is installed between the upper ends of the pair of side plates as a top plate, and the front is used as the entrance and exit. The wafer cassette according to claim 1, wherein the outlet is a distribution port.   The wafer according to claim 1 or 2, wherein a flow opening is formed by laying a restriction plate that divides the other opening between the first and second opposing plates, and a plurality of holding grooves are arranged on the inner surface of the restriction plate. cassette.

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