JP2011108738A - Method for handling of semiconductor wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for handling of a semiconductor wafer, capable of handling even a thin semiconductor wafer with ease, with less aging which makes peeling difficult, reducing remaining adhesive and its movement, allowing repeated use, reducing environmental load, with simplified removal being expected. <P>SOLUTION: The method for handling of the semiconductor wafer 10 prevents damage on a semiconductor wafer 10 by causing an elastic sucker layer 3 stacked on at least a surface among both sides of a support layer 2 of a support jig 1 to suck and hold the thin semiconductor wafer in a detachable manner. The support layer 2 and the elastic sucker layer 3 are formed as the same size and shape of the semiconductor wafer 10. The support layer 2 and the elastic sucker layer 3 are flexible. On the surface of the elastic sucker layer 3, a plurality of pits 5 corresponding to the rough on a surface 11 of the semiconductor wafer 10 are formed. The semiconductor wafer 10 is sucked and held by the elastic sucker layer 3, so that no adhesive tape or adhesive agent is required to be used. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method of handling a semiconductor wafer that can easily handle a thin semiconductor wafer.

From the viewpoint of adapting to a thin semiconductor package, the semiconductor wafer is thinned by back grinding (see Patent Documents 1 and 2), but when thinned to a thickness of 100 μm or less, it is very brittle and easily cracked. Since it will be in the state which is easy to chip, there exists a possibility of damaging, if it accommodates in a crystal case etc. as it is and conveys.
In view of such adverse effects, a method has been proposed in which a semiconductor wafer is attached to an adhesive tape of a support jig before and after the semiconductor wafer is thinned to prevent cracking or chipping of the thinned semiconductor wafer.

  By the way, the adhesive tape of the support jig is also called a back grind tape or a surface protection tape, and is formed by laminating an adhesive on a base material layer (not shown). In order to prevent it and store it in a crystal case or the like, a relatively thick biaxially stretched PET or the like having a base layer thickness of approximately 188 μm or the like must be used.

  There are two types of adhesive for pressure-sensitive adhesive tapes: a pressure-sensitive adhesive type and a type that can be easily peeled off by UV irradiation. In the case of pressure-sensitive adhesive type, a circuit pattern is formed on the semiconductor wafer. When the solder bumps are formed, the adhesive tape cannot be adhered to the semiconductor wafer unless the adhesive strength is strong to some extent. On the other hand, if the adhesive strength is too strong, the adhesive may remain or the semiconductor wafer may break.

  On the other hand, in the case of a type that easily peels when exposed to ultraviolet rays, the adhesive tape can be used only once, resulting in a large amount of waste. Furthermore, in any type, if the adhesive tape is adhered to the semiconductor wafer and left for a long time, the adhesive strength becomes very high, so that the adhesive remains or moves near the solder bumps, and the adhesive tape There is a possibility that the semiconductor wafer may be cracked during peeling.

  Therefore, in the case of rough semiconductor wafers with solder bumps, a method has been proposed in which the back grind tape is adhered and back grinded, and then the back grind tape is peeled off quickly and held in close contact with the holding jig. (See Patent Document 3). However, when this method is adopted, good adhesion and retention can be expected for the back-grind surface of the semiconductor wafer, but there is a risk that adhesion and retention will be insufficient for rough surfaces such as solder bump surfaces of the semiconductor wafer. There can be a situation where the semiconductor wafer is warped and floated during handling.

JP 2009-164476 A JP 2005-191296 A JP 2007-73777 A

  In view of the above situation, a resist-based adhesive is applied on a glass substrate with a spin coater, etc., and a semiconductor wafer is laminated on the surface, and the semiconductor wafer is back-ground and thinned in the back-grinding process as it is for other processes. After that, a method is proposed in which the glass substrate and the semiconductor wafer are peeled off by immersing in a solvent in a solvent tank to dissolve the adhesive of the glass substrate. However, in this method, since the adhesive must be dissolved with the solvent in the solvent tank, the environmental load increases, and the adhesive may not completely dissolve and may remain on the semiconductor wafer. In addition, the amount of adhesive discarded increases, and there is a problem in terms of productivity.

  On the other hand, a method for supporting a thinned semiconductor wafer using a jig having a size larger than the size of the semiconductor wafer is also presented. For example, a method of attaching a thinned semiconductor wafer to a dicing tape frame via a dicing tape is applicable. However, in the case of this method, the tape frame cannot be inserted and held in a crystal case, a substrate storage container called FOUP or FOSB, and it becomes difficult to use the interface with the process apparatus.

  The present invention has been made in view of the above, and can be easily handled even with a thin semiconductor wafer, has little change with time, which makes peeling difficult, reduces the residual or migration of the adhesive, and can be used repeatedly, An object of the present invention is to provide a method of handling a semiconductor wafer that can reduce the load and can be easily attached and detached.

In the present invention, in order to solve the above-mentioned problem, a semiconductor wafer that prevents the damage by detachably holding a thinned semiconductor wafer on an elastic suction layer laminated on at least one side of both sides of a support layer of a support jig. The handling method of
The support layer and the elastic sucker layer are formed in substantially the same size and shape as the semiconductor wafer, and flexibility is imparted to the support layer and the elastic sucker layer, respectively. The surface of the elastic sucker layer is provided with a plurality of recessed holes corresponding to the unevenness of the held surface of the semiconductor wafer.

  In addition, the material for the elastic sucker layer is applied to the material for the support layer, the material for the elastic sucker layer is heated and foamed, and the size of the semiconductor wafer is set to the size of the semiconductor layer for the support layer and the material for the elastic sucker layer. A support jig can be manufactured by processing according to a shape.

  Here, the support jig in the claims is preferably the same size as the semiconductor wafer, but may be slightly wider than the semiconductor wafer from the viewpoint of easy removal of the semiconductor wafer. The elastic sucker layer of the support jig can be formed into an elastic layer using a predetermined foamed resin. This elastic suction layer is laminated and fixed on the front surface, back surface, or front and back surfaces of the support layer.

  Semiconductor wafers include at least φ200, 300, 450, and 600 mm types. Furthermore, the method for handling a semiconductor wafer according to the present invention is used in at least a crystal case, a process capable of handling a substrate storage container called FOUP or FOSB, and inserting the semiconductor wafer.

  According to the present invention, when the thinned semiconductor wafer is held on the support jig, the thinned semiconductor wafer may be pressed and held on the elastic sucker layer of the support jig. If the semiconductor wafer is held on the support jig in this way, the rigidity can be secured and lifted, and the semiconductor wafer integrated with the support jig can be safely stored, transported, and stored.

  On the other hand, when removing the thinned semiconductor wafer from the support jig, the support jig and the semiconductor wafer are separated by fixing the semiconductor wafer to a table or the like and bending and peeling the support jig. The semiconductor wafer can be removed.

  According to the present invention, even a thin semiconductor wafer can be handled easily, there is little change over time that makes it difficult to peel off, and there is an effect that adhesive residue and migration can be reduced. Moreover, the support jig can be used repeatedly, the environmental load can be reduced, and simplification of attachment / detachment can be expected.

  In addition, since a plurality of dent holes are provided on the surface of the elastic sucker layer, even if there are irregularities on the held surface of the semiconductor wafer in contact with the surface of the elastic sucker layer, a plurality of elastic sucker layers are formed on the irregularities of the semiconductor wafer. It is possible to effectively hold the recesses in correspondence. Furthermore, since the elastic sucker layer is formed into a thin film having bubbles with an acrylate resin, better holding and detachment of the semiconductor wafer can be expected than when the elastic sucker layer is formed of other materials.

It is a whole perspective explanatory view showing typically an embodiment of a handling method of a semiconductor wafer concerning the present invention. It is side surface explanatory drawing which shows typically the support jig | tool in embodiment of the handling method of the semiconductor wafer which concerns on this invention. FIG. 3 is an enlarged explanatory view showing a portion III of FIG. 2 in an enlarged manner.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A semiconductor wafer handling method in the present embodiment is a semiconductor wafer thinned on an elastic sucker layer 3 laminated on a support layer 2 of a support jig 1. This is a handling method in which 10 is adsorbed and held to give rigidity to the thin and fragile semiconductor wafer 10 to prevent its damage.

  As shown in FIGS. 1 to 3, the support jig 1 is laminated and bonded to at least the entire surface of the support layer 2 for the semiconductor wafer 10 and the front and back surfaces of the support layer 2 so that the semiconductor wafer 10 can be freely attached and detached. An elastic sucker layer 3 for adsorbing and holding is provided. The support layer 2 and the elastic sucker layer 3 are formed in a planar circle having the same size and shape as the semiconductor wafer 10 and are both flexible.

  The support layer 2 is thinly formed into a bendable rigid disk using, for example, a predetermined material, and is stored in a crystal case (not shown), a substrate storage container called FOUP or FOSB. The material of the support layer 2 is not particularly limited, but biaxially stretched PET, amorphous PET, polycarbonate, vinyl chloride resin, polypropylene, glass epoxy (glass fiber woven fabric hardened with epoxy resin), etc. A sheet is raised.

  Among these materials, it is optimal to use a biaxially stretched PET sheet having a high elastic modulus. When a biaxially stretched PET sheet having a thickness of 188 μm or 250 μm is used as the material of the support layer 2, it is preferable because there is no habit after bending and peeling the semiconductor wafer 10.

  The elastic sucker layer 3 is formed into an elastic thin film having a large number of foamed bubbles 4 using a predetermined material, for example, and a plurality of minute recesses 5 are randomly formed on the surface. Examples of the material of the elastic sucker layer 3 include various resin aqueous solutions and emulsions such as acrylate resin, polyester, polyvinyl chloride, polyethylene, polypropylene, nylon, and urethane. An acrylic ester resin that can be expected to be held and detached is most suitable.

  The material of the elastic sucker layer 3 is appropriately mixed with a plasticizer, a foaming agent, a foam stabilizer, and a thickener to adjust the foamed state of the elastic sucker layer 3. Further, as shown in FIG. 3, the plurality of recessed holes 5 are appropriately formed in, for example, a hemispherical shape or a semi-elliptical shape and exposed.

  The semiconductor wafer 10 is made of, for example, a silicon wafer having a diameter of 200 mm or 300 mm and is thinned to a thickness of 100 μm or less, specifically about 25 μm by back grinding, and is held to be in contact with the elastic sucker layer 3 of the support jig 1. In other words, a circuit pattern and necessary solder bumps are formed on the surface 11 so as to be uneven. A protective back grind tape (not shown) is detachably adhered to the surface 11 of the semiconductor wafer 10 during back grinding.

  In the above configuration, when the support jig 1 is manufactured, the material for the elastic sucker layer 3 is applied to the surface of the material for the support layer 2, and these are set in a drying furnace to foam the material for the elastic sucker layer 3. Then, after taking out from the drying furnace, the support jig 1 can be manufactured by cutting the material for the support layer 2 and the material for the elastic sucker layer 3 according to the size and shape of the semiconductor wafer 10.

  At this time, the elastic sucker layer 3 can be foamed with a foaming agent, but is not necessarily limited thereto. For example, air bubbles are mechanically mixed without using a foaming agent, and the material for the elastic sucker layer 3 is coated on the support layer 2 with a gravure coater, a comma coater or the like, and is continuously introduced into a drying furnace to be elastic sucker After the material for the layer 3 is foamed and taken out from the drying furnace, the elastic sucker layer 3 can be obtained by sticking a 25 μm thick biaxially stretched polypropylene film to the foamed elastic sucker layer 3.

  Next, when holding the thinned semiconductor wafer 10 on the support jig 1, the back grind tape is peeled off from the surface 11 of the semiconductor wafer 10, and the semiconductor wafer is placed on the flexible elastic sucker layer 3 of the support jig 1. 10 surfaces 11 may be adsorbed and held. At this time, since a large number of minute recesses 5 are exposed on the surface of the elastic sucker layer 3, even if the surface 11 of the semiconductor wafer 10 is uneven due to circuit patterns or solder bumps, The recessed holes 5 of the elastic sucker layer absorb correspondingly and can be effectively adsorbed by the sucker effect.

  If the semiconductor wafer 10 is sucked and held on the support jig 1 in this way, the semiconductor wafer 10 which is thin and fragile and easily broken can be given rigidity and lifted by hand. 10 can be safely stored in the crystal case.

  Next, when the thin semiconductor wafer 10 is removed from the support jig 1 in the next process, the lid of the crystal case used in the next process is removed, and the semiconductor wafer 10 integrated with the support jig 1 is taken out of the crystal case. If vacuum suction is performed on a porous ceramic suction table and the support jig 1 is gradually bent from the end and gradually peeled off, the support jig 1 and the semiconductor wafer 10 are completely separated to form a thin semiconductor wafer. 10 can be removed.

  When the semiconductor wafer 10 is removed from the support jig 1 in this way, the semiconductor wafer 10 is sucked and held by a full-surface suction hand (not shown), and the semiconductor wafer 10 is lifted from the suction table where the vacuum pump is stopped. Can be introduced smoothly.

  When the process of the process apparatus is completed and the semiconductor wafer 10 is discharged, the semiconductor wafer 10 is taken out and fixed on the suction table, and the elastic sucker layer 3 of the support jig 1 is attached to the semiconductor wafer 10 via a pressure roller. If the support jig 1 is lifted by releasing the vacuum suction of the sticking table, the semiconductor wafer 10 integrated with the support jig 1 can be stored again in the crystal case.

  According to the above configuration, since the semiconductor wafer 10 is sucked and held on the elastic suction layer 3 of the support jig 1, there is no need to use an adhesive tape or its adhesive. Therefore, even if a circuit pattern or a solder bump is formed on the semiconductor wafer 10, the semiconductor wafer 10 can be safely sucked and held. Further, there is no possibility that the adhesive remains on the semiconductor wafer 10 or the semiconductor wafer 10 breaks. Further, since the support jig 1 and its elastic suction layer 3 can be used a plurality of times, it is possible to reliably prevent the generation of a large amount of waste, and to effectively prevent cracking of the semiconductor wafer 10 during peeling. it can.

  In addition, since the recessed holes 5 of the elastic sucker layer 3 correspond to the unevenness of the semiconductor wafer 10 and are effectively adsorbed, the semiconductor wafer 10 is sufficiently kept in close contact with the surface 11 with solder bumps. Therefore, it is possible to prevent the semiconductor wafer 10 from being warped and lifted during handling with a simple configuration.

  In addition, since it is not necessary to dissolve the adhesive with the solvent in the solvent tank, it is possible to greatly reduce the environmental load and significantly improve the productivity. Furthermore, since the support layer 2 and the elastic sucker layer 3 are the same size and shape as the semiconductor wafer 10, the support jig 1 can be inserted and held as it is in the crystal case or the substrate storage container, and the interface with the process apparatus can also be used. Use is really convenient.

DESCRIPTION OF SYMBOLS 1 Support jig 2 Support layer 3 Elastic sucker layer 4 Foam bubble 5 Recess hole 10 Semiconductor wafer 11 Surface (surface to be held)

Claims (1)

A method for handling a semiconductor wafer that prevents the damage by detachably holding a thinned semiconductor wafer on an elastic sucker layer laminated on at least one side of the support layer of the support jig,
The support layer and the elastic sucker layer are formed in substantially the same size and shape as the semiconductor wafer, and flexibility is imparted to the support layer and the elastic sucker layer, respectively. A method of handling a semiconductor wafer, comprising: forming a plurality of recess holes corresponding to the irregularities of a held surface of the semiconductor wafer on a surface of the elastic sucker layer.

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