JP6588391B2 - Support jig for semiconductor wafer and its handling method - Google Patents

Description

  The present invention relates to a semiconductor wafer support jig for a semiconductor wafer to be wet processed and a method for handling the same.

  Conventional semiconductor wafers are made of, for example, a silicon wafer that is easy to be highly purified and whose resistivity is easily controlled, a circuit pattern is formed on the front surface, and the back grind surface on the back surface is subjected to back grind processing, so that it is 100 μm or less. The back-grinded surface that has been back-grinded is subjected to stress relief treatment with a chemical solution to remove the damage layer damaged by back-grinding, and then immersed in a high-temperature plating solution. (See Patent Documents 1 and 2).

  When a semiconductor wafer is thinned to a thickness of 100 μm or less, particularly 70 μm or less, by back grinding, it becomes very brittle and easily bent and easily cracked, which may cause problems due to insufficient strength during plating. In view of this point, conventionally, after plating, a thinned semiconductor wafer is bonded to a predetermined protective member to ensure a necessary strength, and then immersed in a high-temperature plating solution. Examples of the predetermined protective member include a flexible resin sheet having flexibility.

JP 2014-077171 A JP 2014-105360 A

  A conventional semiconductor wafer is immersed in a plating solution after being bonded to a predetermined protective member as described above. However, when the temperature changes due to immersion in a high-temperature plating solution, the linear expansion coefficient with the protective member is large. Due to the difference, an area to be originally protected by being partially peeled off from the protective member may be affected by the plating solution, or may be completely peeled off from the protective member and damaged. As a method for solving this problem, there is a method in which a material having the same linear expansion coefficient as that of the semiconductor wafer, for example, silicon or a predetermined glass plate is bonded to the semiconductor wafer as a protective member.

  However, although silicon and certain glass plates have the same linear expansion coefficient as semiconductor wafers, they are hard and inflexible, so they can be easily peeled off after plating to avoid damaging thin and brittle semiconductor wafers. As a result, there arises a new problem that hinders later processes. In addition, since the protective member is indispensable for the plating process of the semiconductor wafer thinned by the back grind, it is a member that can be used repeatedly rather than being discarded every time the plating process is performed from the viewpoint of cost reduction. preferable.

  The present invention has been made in view of the above, and is rarely peeled off from a thin semiconductor wafer during wet processing, can be easily peeled off without damaging the thin semiconductor wafer after wet processing, and can be used repeatedly. It aims at providing the support jig for semiconductor wafers, and its handling method.

In the present invention, in order to solve the above problems , among the plating solution, the chemical solution, and the etching solution, at least a jig that is bonded to a semiconductor wafer wet-treated with the plating solution ,
An endless rigid support frame layer having an opening larger than that of the semiconductor wafer, and a flexible adhesive that is attached to the rigid support frame layer to cover the opening and removably adheres to the semiconductor wafer in the opening. Including a film layer,
The semiconductor wafer is a silicon wafer thinned to a thickness of 100 μm or less by back grinding.
An adhesive film layer is formed of a polyimide film having a thickness of 50 μm or less and a silicone-based adhesive material having a thickness of 5 μm or more and 50 μm or less laminated on the polyimide film and adhered to the back surface of the rigid support frame layer. The linear expansion coefficient is 1 ppm / ° C. or more and 5 ppm / ° C. or less .

Further, in order to solve the above-mentioned problems in the present invention, the semiconductor wafer is accommodated in the opening portion of the rigid support frame layer of the support jig for semiconductor wafer according to claim 1, and the semiconductor wafer is made of a silicone-based adhesive film layer. After the adhesive material is adhesively supported, the semiconductor wafer is wet-treated with at least a plating solution among a plating solution, a chemical solution, and an etching solution .

  Here, the semiconductor wafer in the claims is a wafer made of a silicon wafer having a diameter of at least 150, 200, 300, or 450 mm and wet-treated with liquids such as various plating solutions, chemical solutions, and etching solutions. The silicone-based pressure-sensitive adhesive material for the pressure-sensitive adhesive film layer has a very low elastic modulus as compared with the polyimide film. Therefore, the linear expansion coefficient as the adhesive film layer is substantially the same as the linear expansion coefficient of the polyimide film.

  According to the present invention, since the linear expansion coefficients of the semiconductor wafer and the adhesive film layer are substantially equal, even if the semiconductor wafer is subjected to a predetermined wet treatment and a temperature change occurs, the semiconductor wafer is separated from the adhesive film layer. Can be suppressed. Moreover, since a flexible adhesive film layer is used, a thin and fragile semiconductor wafer can be safely and easily peeled after a predetermined wet treatment. Further, since the semiconductor wafer support jig is not composed of only the adhesive film layer but is composed of a combination of the adhesive film layer and the rigid support frame layer, it can be repeatedly used and adhered.

According to the present invention, since the linear expansion coefficients of the semiconductor wafer and the adhesive film layer are substantially the same, even if the semiconductor wafer is immersed in the plating solution and plated to cause a temperature change, the semiconductor wafer is partially removed from the adhesive film layer. Thus, it is possible to effectively prevent an area that should be protected by peeling off from being affected by the plating solution, or that the semiconductor wafer is completely peeled off from the adhesive film layer and damaged. Further, since it is not necessary to use hard silicon or a predetermined glass plate, the thin and fragile semiconductor wafer can be safely and easily peeled off from the flexible adhesive film layer after the plating process.
Accordingly, it is possible to prevent the soldering process after the plating process from being hindered. In addition, since the support jig for semiconductor wafer has a rigid support frame layer having excellent mechanical strength, it can be repeatedly used and adhered, and reduction of running cost and the like can be expected. In addition, since the adhesive film layer can adhere and support not the part of the opposing surface of the semiconductor wafer but also the entire surface, the semiconductor wafer can be held in a stable manner over a wide area. Furthermore, since the polyimide film of the adhesive film layer is thinned to improve followability, the semiconductor wafer can be adhered to the adhesive film layer without any gap.

It is a section explanatory view showing typically an embodiment of a support jig for semiconductor wafer concerning the present invention. It is a plane explanatory view showing typically an embodiment of a semiconductor wafer support jig concerning the present invention.

  Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. A semiconductor wafer support jig 10 according to this embodiment is a thin semiconductor wafer 1 having a thickness of 100 μm or less as shown in FIGS. An endless rigid support frame layer 11 having a larger opening 12, and a flexible adhesive that is attached to the rigid support frame layer 11 to cover the opening 12 and adhere the semiconductor wafer 1 in the opening 12. The thin adhesive film layer 13 is provided, and the linear expansion coefficient of the thin adhesive film layer 13 is set to a low linear expansion coefficient substantially equal to that of the semiconductor wafer 1.

  The semiconductor wafer 1 is made of, for example, a silicon wafer having a diameter of 300 mm, and an uneven circuit pattern is formed on the surface by a lithography technique or the like. From the viewpoint of contributing to the manufacture of a thin semiconductor package, the back grind surface on the back surface is formed by a back grind apparatus. By back grinding, the thickness is reduced from about 750 μm to 100 μm or less. A flat orientation flat or a substantially semi-circular notch is formed on the periphery of the semiconductor wafer 1 to facilitate the determination of crystal orientation and alignment.

  After such a semiconductor wafer 1 is thinned to a thickness of 100 μm or less, the back-grinded surface to be back-grinded is subjected to stress relief treatment with a chemical solution such as hydrofluoric acid, thereby causing damage caused by back-grinding. The layer is removed and then immersed in a hot plating solution.

  The rigid support frame layer 11 of the semiconductor wafer support jig 10 has, for example, a glass epoxy resin that is excellent in strength, thermal conductivity, heat resistance, and electrical characteristics and is suitable for use in thin products. The semiconductor wafer 1 is accommodated and surrounded via a gap. The rigid support frame layer 11 is formed on a flat plate having a larger diameter than that of the semiconductor wafer 1 and has a thickness of 100 to 1500 μm, preferably about 200 to 1000 μm from the viewpoint of handling work. The thickness is preferably about 300 to 750 μm.

  The pressure-sensitive adhesive film layer 13 is laminated on a thin polyimide film (PI) 14 having a thickness of 50 μm or less and the thin polyimide film 14, and has a slight adhesiveness that is excellent in heat resistance, weather resistance, water repellency, adhesion, chemical resistance, and the like. And a silicone rubber 15 having a two-layer structure and a linear expansion coefficient of 5 ppm / ° C. or less, preferably 4 ppm / ° C. or less, more preferably 3 ppm / ° C. or less.

  The linear expansion coefficient of the polyimide film 14 is in the range of 1 to 5 ppm / ° C., preferably 1 to 4 ppm / ° C., more preferably 1 to 3 ppm / ° C. from the viewpoint of making it substantially equal to the linear expansion coefficient of the semiconductor wafer 1. The Therefore, the polyimide film 14 is (1) aromatic diamines containing 70 mol% or more of benzoxazole structure, and aromatic tetracarboxylic acids containing 70 mol% or more of pyromellitic acid residues. (2) Aromatic diamines are aromatic diamines containing 70 mol% or more of phenylene diamine structure, and aromatic tetracarboxylic acids are 70 mol% of biphenyl tetracarboxylic acid structure. A film which is an aromatic tetracarboxylic acid contained above or (3) a block copolymerized polyimide-silica hybrid film obtained by thermosetting an alkoxy group-containing silane-modified block copolymerized polyamic acid is selectively used. .

  The polyimide film 14 having a linear expansion coefficient of 5 ppm / ° C. or less was described in, for example, JP-A Nos. 5-70590, 2000-119419, 2007-56198, and 2005-68408. It can be manufactured by a manufacturing method. Examples of the commercially available polyimide film 14 having a linear expansion coefficient of 5 ppm / ° C. or less include XENOMAX (manufactured by Toyobo Co., Ltd .: trade name), Pomilan T (manufactured by Arakawa Chemical Industries Ltd .: trade name), and the like.

  Such a polyimide film 14 is formed to have a thickness of 15 to 50 μm, preferably about 25 to 45 μm, more preferably about 30 to 40 μm, from the viewpoint of ensuring followability and flexibility with respect to the semiconductor wafer 1. It faces the flat back surface of the support frame layer 11 via a silicone rubber 15.

  The silicone rubber 15 has a very low elastic modulus compared to the polyimide film 14, and the linear expansion coefficient as the adhesive film layer 13 is substantially the same as the linear expansion coefficient of the polyimide film 14. Become. The silicone rubber 15 is formed to have a thickness of 5 to 50 μm, preferably about 10 to 40 μm, more preferably about 12 to 25 μm, and is adhered to the back surface of the rigid support frame layer 11 so that the round opening 12 extends downward. The semiconductor wafer 1 accommodated in the opening 12 functions so as to be detachably adhered and supported.

  In the above, when the thin semiconductor wafer 1 subjected to the stress relief process is plated, the thin semiconductor wafer 1 is accommodated in the opening 12 of the rigid support frame layer 11 of the semiconductor wafer support jig 10, and the thin semiconductor wafer 1 is carefully pressed from above with a roller or the like, and the entire opposite surface of the semiconductor wafer 1 facing the adhesive film layer 13 is adhesively supported on the adhesive film layer 13 without gaps. The converted semiconductor wafer 1 can be plated by being immersed in a high-temperature plating solution.

  According to the above configuration, since the linear expansion coefficients of the semiconductor wafer 1 and the adhesive film layer 13 are substantially equal, even if the semiconductor wafer 1 is subjected to a plating process and a temperature change occurs, the semiconductor wafer 1 is partially separated from the adhesive film layer 13. Thus, it is possible to effectively prevent the area that should be protected by peeling off from being affected by the plating solution, or the semiconductor wafer 1 from being completely peeled off from the adhesive film layer 13 and damaged. Further, since it is not necessary to use hard silicon or a predetermined glass plate, the thin and fragile semiconductor wafer 1 can be safely and easily peeled off from the flexible adhesive film layer 13 after plating. Therefore, there is no problem in the soldering process after the plating process.

  Further, since the support jig 10 for semiconductor wafer has the rigid support frame layer 11 having excellent mechanical strength, it can be repeatedly used and adhered, and a reduction in running cost and the like can be greatly expected. In addition, since the adhesive film layer 13 adheres and supports not the part of the opposing surface of the semiconductor wafer 1 but the entire surface thereof, the semiconductor wafer 1 can be held in a stable posture over a wide area. Furthermore, since the polyimide film 14 of the adhesive film layer 13 is thinned to improve followability, the semiconductor wafer 1 can be adhered to the adhesive film layer 13 without a gap.

In the above embodiment, the rigid support frame is formed in a flat ring shape from glass epoxy resin. However, if there is no particular problem in wet processing and there is no problem with rust prevention, etc., the rigid support frame is flat with stainless steel (SUS) or the like. You may form in a substantially ring shape. Further, an operation knob may be formed to protrude from the outer peripheral edge of the rigid support frame .

  The semiconductor wafer support jig and the method for handling the same according to the present invention are used in the field of semiconductor manufacturing.

DESCRIPTION OF SYMBOLS 1 Semiconductor wafer 10 Support jig 11 for semiconductor wafers Rigid support frame layer 12 Opening part 13 Adhesive film layer 14 Polyimide film 15 Silicone rubber (silicone adhesive material)

Claims (2)

Of the plating solution, chemical solution, and etching solution, a semiconductor wafer support jig to be bonded to a semiconductor wafer wet-treated with at least the plating solution ,
An endless rigid support frame layer having an opening larger than that of the semiconductor wafer, and a flexible adhesive that is attached to the rigid support frame layer to cover the opening and removably adheres to the semiconductor wafer in the opening. Including a film layer,
The semiconductor wafer is a silicon wafer thinned to a thickness of 100 μm or less by back grinding.
An adhesive film layer is formed of a polyimide film having a thickness of 50 μm or less and a silicone-based adhesive material having a thickness of 5 μm or more and 50 μm or less laminated on the polyimide film and adhered to the back surface of the rigid support frame layer. A semiconductor wafer support jig having a linear expansion coefficient of 1 ppm / ° C. or more and 5 ppm / ° C. or less . The semiconductor wafer is accommodated in the opening of the rigid support frame layer of the semiconductor wafer support jig according to claim 1, and after the semiconductor wafer is adhesively supported on the silicone-based adhesive material of the adhesive film layer , the semiconductor wafer is A method of handling a semiconductor wafer support jig, wherein a wet treatment is performed with at least a plating solution of a plating solution, a chemical solution, and an etching solution .

Images