JP2009043962A - Method for manufacturing semiconductor apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor apparatus which is manufactured simply and inexpensively. <P>SOLUTION: Firstly, a stripping layer 110 which can absorb ultraviolet light is formed on a support substrate 100 transparent to the ultraviolet light, and, thereafter, an adhesive layer 130 which can absorb ultraviolet light, and chips 11 and 12 are laminated in this order from a stripping layer 110 on a predetermined region of a surface of the stripping layer 110. For the stripping layer 110, a material is used whose light volume per unit area for hardening by ultraviolet light irradiation is a first light volume, and, for the adhesive layer 130, a material is used whose light volume per unit area for hardening by ultraviolet light irradiation is a second light volume smaller than the first light volume. Thereafter, ultraviolet light L1 having a light volume per unit area less than the first light volume and larger than the second light volume is irradiated to the adhesive layer 130 through the support wafer 100 and the stripping layer 110 from a support wafer 100 side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semiconductor device suitable for stacking a plurality of chips.

  Along with the recent miniaturization and higher frequency, there are an increasing number of cases where a three-dimensional integrated module in which a plurality of chips are stacked and arranged is manufactured at the wafer level. This three-dimensional integrated module can typically be manufactured as follows.

  First, a release layer that absorbs ultraviolet light and an adhesive layer made of a thermosetting resin are sequentially formed on the support wafer from the support wafer side, and then a plurality of chips are arranged on the adhesive layer. Next, heat is applied to the adhesive layer to fix each chip to the support wafer. Next, an interlayer insulating film is formed on the surface of each chip, and a wiring layer and a via electrically connected to each chip are formed in the interlayer insulating film, and a plurality of chips are further stacked thereon. To do. Then, by repeating this process as many times as necessary, three-dimensional integration of the chip is performed. Next, the release layer is deteriorated by irradiating ultraviolet light from the back side of the support wafer. Finally, the release layer is peeled off to separate each chip from the support wafer.

  Although it is possible to manufacture a three-dimensional integrated module in this way, when heat is applied to an adhesive layer made of a thermosetting resin, gas is generated from the thermosetting resin, and the thermosetting resin Various problems may occur, such as the formation of bubbles in the inside.

  Therefore, it is conceivable to use an ultraviolet curable resin instead of the thermosetting resin. However, in that case, since the release layer immediately below the adhesive layer is also made of an ultraviolet curable resin, when the ultraviolet light is irradiated from the back side of the support wafer, the ultraviolet light is directly below the adhesive layer. Since it is absorbed by the release layer and does not reach the adhesive layer, there is a problem that the adhesive layer cannot be cured.

  Therefore, in order to solve such a problem, many literatures disclose techniques for separating a chip from a supporting wafer without irradiating the release layer with ultraviolet light. For example, Patent Documents 1 and 2 disclose a technique for separating a chip from a support wafer only by applying a force from the outside using a material having low adhesion to the support wafer as a release layer. For example, Patent Documents 3 to 5 disclose techniques for separating a chip from a support wafer by using a metal material as the release layer and chemically wet-etching the release layer. For example, Patent Documents 6 to 9 disclose a technique for separating a chip from a support wafer by using a silicon material as a release layer and exposing the release layer to an atmosphere containing a halogenated fluorine gas to perform etching. Yes. For example, Patent Document 10 discloses a technique for separating a chip from a support wafer by using a heat-foaming adhesive material as a release layer and heating to a temperature equal to or higher than the foaming start temperature of the heat-foaming adhesive material.

JP 2002-343923 A Patent No. 3583396 Patent 3773896 PR Japanese Patent No. 3861669 Japanese Patent No. 3116085 Patent No. 3579492 JP 2001-272923 A JP 2004-153290 A Patent No. 3406893 Japanese Patent No. 3892774

  However, the techniques of Patent Documents 1 and 2 have a problem that peeling is likely to occur during the manufacturing process. Further, in the techniques of Patent Documents 3 to 5, it is necessary to use a highly selective metal material and an etchant, and when the selectivity is poor, it is necessary to attach a protective film. is there. In the techniques of Patent Documents 6 to 9, there is a problem that the cost of the release layer is high and the manufacturing cost is high. In addition, when the release layer cannot be removed, there is a problem that it is necessary to add a special process. Further, the technique of Patent Document 10 has a problem that the material is limited and it is difficult to manufacture.

  The present invention has been made in view of such problems, and an object thereof is to provide a method of manufacturing a semiconductor device which can be manufactured stably, simply and inexpensively.

  In the semiconductor device manufacturing method of the present invention, first, in the arranging step, a release layer capable of absorbing ultraviolet light is formed on a support substrate transparent to ultraviolet light, and then a predetermined region on the surface of the release layer is formed. In addition, an adhesive layer capable of absorbing ultraviolet light and a chip are stacked in this order from the release layer side. However, the release layer uses a material whose light amount per unit area necessary for curing by ultraviolet light irradiation is the first light amount, and the adhesive layer per unit area necessary for curing by ultraviolet light irradiation. A material whose second light amount is smaller than the first light amount is used. Next, in the irradiation step, the adhesive layer is irradiated with first ultraviolet light having a light amount per unit area smaller than the first light amount and larger than the second light amount from the support substrate side through the support substrate and the release layer.

  In the method for manufacturing a semiconductor device of the present invention, the first ultraviolet light having a light amount per unit area smaller than the first light amount and larger than the second light amount is irradiated from the support substrate side to the adhesive layer through the support substrate and the release layer. Is done. Thereby, for example, the adhesive layer can be cured to such an extent that the chip does not shift. Thus, this method does not use a material or a method that causes a new defect, and does not require a special material or method. In addition, after the adhesive layer is cured, the release layer is irradiated with ultraviolet light larger than the first light amount from the support substrate side through the support substrate to deteriorate the release layer. In the case of reducing the adhesion between the support substrate and the support substrate, a material having high adhesion to the support substrate can be used as the release layer. Thereby, it is possible to eliminate the possibility that the support substrate is peeled off during the manufacturing process.

  According to the method for manufacturing a semiconductor device of the present invention, the first ultraviolet light having a light amount per unit area smaller than the first light amount and larger than the second light amount is applied from the support substrate side through the support substrate and the release layer. Therefore, it is possible to manufacture a semiconductor device by a stable, simple and inexpensive method.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an example of a cross-sectional configuration of a semiconductor device 1 according to an embodiment of the present invention. FIG. 1 is a schematic representation, which differs from actual dimensions and shapes.

  The semiconductor device 1 has a stacked structure in which, for example, a sealing layer 10, an interlayer insulating film 20, and a sealing layer 30 are stacked in this order. The semiconductor device 1 is a three-dimensional integrated module in which chips 11, 12, and 31 are embedded in the stacked structure, and is thinned by eliminating a support substrate such as a silicon substrate.

  In the sealing layer 10, the chips 11 and 12 are embedded with the functional surfaces 11 </ b> A and 11 </ b> B facing the interlayer insulating film 20 side. The functional surfaces 11A and 11B of the chips 11 and 12 are disposed in the same plane as the interface between the sealing layer 10 and the interlayer insulating film 20, respectively. Further, the surfaces of the chips 11 and 12 opposite to the functional surfaces 11A and 11B are exposed on the surface of the sealing layer 10 (the bottom surface of the semiconductor device 1). A plurality of metal layers 13 are arranged around the chips 11 and 12 in the sealing layer 10, and one surface of each metal layer 13 is the same as the functional surfaces 11 </ b> A and 11 </ b> B of the chips 11 and 12. It is arranged in the plane.

  A chip 31 is embedded in the sealing layer 30 with the functional surface 31A facing the interlayer insulating film 20 side. The functional surface of the chip 31 is disposed in the same plane as the interface between the sealing layer 30 and the interlayer insulating film 20, and is disposed to face the functional surface of the chip 11. Further, the surface of the chip 31 opposite to the functional surface is exposed on the surface of the sealing layer 30 (the upper surface of the semiconductor device 1).

  A plurality of metal layers 21 and a plurality of vias 22 are embedded in the interlayer insulating film 20. Of the plurality of metal layers 21, two metal layers 21 are formed at the interface with the sealing layer 10, and one of the metal layers 21 is electrically connected to the chip 11, and the other metal layer 21. Are electrically connected to the chip 12. Further, the metal layer 21 is also formed in a portion facing the metal layer 21 electrically connected to the chip 12.

  Further, one via 22 among the plurality of vias 22 is formed so as to penetrate the interlayer insulating film 20, and the metal layer 21 electrically connected to the chip 11 and the functional surface of the chip 31 are electrically connected to each other. Connected to. Moreover, these are electrically connected between the metal layer 21 electrically connected to the chip 12 and the metal layer 21 formed in a portion facing the metal layer 21 electrically connected to the chip 12. A plurality of vias 22 are formed. Furthermore, a plurality of vias 22 are also formed between the metal layer 21 formed in a portion facing the metal layer 21 electrically connected to the chip 12 and the interface between the sealing layer 30.

  Here, the sealing layers 10 and 30 are made of, for example, an epoxy resin, a silicone resin, or a polyimide resin. The interlayer insulating film 20 is made of, for example, an epoxy resin, a silicone resin, or a polyimide resin. The chips 11, 12, and 31 are, for example, a DRAM (Dynamic Random Access Memory), a logic IC (Integrated Circuit), a ferrite, a DSP (Digital Signal Processor), or a passive chip component. The metal layer 21 is made of, for example, copper, titanium, aluminum, or gold, and the via 22 is made of, for example, copper, tin, gold, or a solder material.

  Next, an example of a manufacturing method of the semiconductor device 1 of the present embodiment will be described.

  2A to 2E show a cross-sectional configuration for explaining an example of a manufacturing method of the semiconductor device 1. 3A to 3D are cross-sectional configurations for explaining the process following FIG. 2E, and FIGS. 4A to 4D are for explaining the process following FIG. 3D. Each of the cross-sectional configurations is shown. 2 to 4 are schematic representations, and are different from actual dimensions and shapes.

  First, the peeling layer 110 is formed on the entire surface of the transparent support wafer 100 (FIG. 2A).

  Here, the support wafer 100 is made of a material transparent to ultraviolet light, such as quartz glass. The release layer 110 is a material that can absorb ultraviolet light, and in the same wavelength band (for example, a wavelength band including 355 nm), the amount of light α per unit area necessary for curing by ultraviolet light irradiation ( The first light quantity) is made of a material larger than that of the adhesive layer 120 described later.

  In the present embodiment, “curing” means that the curing reaction rate reaches approximately 90% or more.

  Next, if necessary, heat is applied to the release layer 110 to thermally cure the release layer 110, and if necessary, a metal layer 120 such as a wiring layer or an alignment mark (for mounting a chip). (Not shown) is formed (FIG. 2B).

  Here, the metal layer 120 is obtained by, for example, laminating a metal layer 120A made of titanium and a metal layer 120B made of copper in order from the peeling layer 110 side.

  Next, an adhesive layer 130 is formed in a region where the chips 11 and 12 are to be disposed (FIG. 2C).

  Here, the adhesive layer 130 is a material capable of absorbing ultraviolet light, and the light amount β (second light amount) per unit area necessary for curing by ultraviolet light irradiation is higher than that of the release layer 110. It is made of a small material and includes, for example, a phenol resin, an epoxy resin, an alkyd resin, a polyimide resin, a novolac resin, an acrylic resin, an acrylate resin, a styrene resin, or an ABS (acrylonitrile-butadiene-styrene) resin.

Next, after disposing the chips 11 and 12 on the surfaces of the adhesive layer 130 and the metal layer 120, the amount of light γ per unit area per unit area of the release layer 110 as shown in the following formula (1). UV light L1 that is smaller than the light amount α and larger than the light amount β per unit area of the adhesive layer 130 is applied to the adhesive layer 130 from the support wafer 100 side through the support wafer 100 and the release layer 110 (FIG. 2 ( D)). For example, using the LD pumped YVO ₄ laser, wavelength is irradiated at a time across the ultraviolet light L1 of 355nm of the third harmonic of the LD pumped YVO ₄ laser to the entire back surface of the supporting wafer 100. As a result, the ultraviolet light L1 passes through the support wafer 100 and the release layer 110 with high transmittance (for example, about 80%) and is absorbed by the adhesive layer 130, so that, for example, the adhesive layer 130 does not cause misalignment of the chip. Can be cured efficiently. In FIG. 2E, the cured adhesive layer 130 is represented as an adhesive layer 130A.
β <γ <α Formula (1)

  Thus, in this method, when the adhesive layer 130 is cured, a material or method that causes a new problem is not used. Moreover, it is not necessary to use special materials and methods.

  Next, for example, after the chips 11 and 12 are sealed with a sealing material made of epoxy resin, silicone resin, or polyimide resin, if necessary, back grinding is performed to flatten the surface (FIG. 3A). ). Thereby, the sealing layer 10 with the surface of the chip 11 exposed on the surface is formed.

Next, after the release layer 140 and the support wafer 150 are bonded onto the sealing layer 10, the amount of light δ per unit area per unit area of the release layer 110 is expressed as shown in the following formula (2). The release layer 110 is irradiated with ultraviolet light L2 larger than the light amount α from the support wafer 100 side through the support wafer 100 (FIG. 3B). For example, using the LD pumped YVO ₄ laser, the wavelength is focused ultraviolet light L1 of 355nm of the third harmonic of the LD pumped YVO ₄ laser with a lens 160, an ultraviolet light L2 condensed, the support wafer 100 The surface is swept and the release layer 110 is irradiated. That is, ultraviolet light containing the same wavelength component as the wavelength of ultraviolet light when the adhesive layer 130 is cured (that is, ultraviolet light from the same light source) is irradiated.
α <δ Formula (2)

  At this time, the ultraviolet light L2 passes through the release layer 110 with a high transmittance (for example, about 80%), but since the amount of light δ per unit area is large, the release layer 110 can be sufficiently deteriorated. Thereby, the adhesiveness of the support wafer 100 and adhesive layer 130A by the peeling layer 110 can be reduced. Note that in FIG. 3C, the release layer 110 after deterioration is represented as a release layer 110A.

  Note that the ultraviolet light L2 may be irradiated before the release layer 140 and the support wafer 150 are bonded together.

  Thus, in this method, in order to reduce the adhesion between the support wafer 100 and the adhesive layer 130A by the release layer 110, the release layer 110 is irradiated with the ultraviolet light L2. Therefore, even if a material having low adhesion between the support wafer 100 and the adhesive layer 130A is not used as the release layer 110, the adhesion between the support wafer 100 and the adhesive layer 130A due to the release layer 110 can be lowered afterwards. Therefore, a material having high adhesion to the support wafer 100 and the adhesive layer 130 </ b> A can be used as the release layer 110.

  Next, the peeling layer 110 is peeled off from the support wafer 100, and the wafer 170 made of each layer stacked above this including the peeling layer 110 is separated from the support wafer 100 (FIG. 3D).

  Next, after the peeling layer 110 attached to the surface of the wafer 170 is removed, back grinding is performed to flatten the surface (FIG. 4A). As a result, the functional surfaces of the chips 11 and 12 and the surface of the metal layer 13 are exposed on the surface of the wafer 170.

  Next, after the interlayer insulating film 10, the metal layer 21, and the via 22 are formed at predetermined positions on the surface of the wafer 170, the chip 31 is disposed at the predetermined position on the surface (FIG. 4B). .

  Next, for example, after sealing the chip 31 with a sealing material made of an epoxy resin, a silicone resin, or a polyimide resin, if necessary, back grinding is performed to flatten the surface (FIG. 4C). Thereby, the sealing layer 30 with the surface of the chip 31 exposed on the surface is formed.

Next, in the same manner as in the step of FIG. 3B, ultraviolet light L3 having a light quantity δ per unit area larger than the light quantity α per unit area of the release layer 140 is passed from the support wafer 150 side through the support wafer 150. Then, the release layer 140 is irradiated (FIG. 4C). For example, using the LD pumped YVO ₄ laser, the wavelength is focused ultraviolet light of 266nm in fourth harmonic of LD pumped YVO ₄ laser with a lens 160, an ultraviolet light L3 condensed, the surface of the support wafer 150 The release layer 140 is irradiated by sweeping. Note that, using an excimer laser, ultraviolet light having a wavelength of 248 nm may be condensed by the lens 160, and the condensed ultraviolet light L3 may be irradiated to the peeling layer 140 by sweeping the surface of the support wafer 150. . Thereby, since the peeling layer 140 deteriorates, the adhesiveness of the support wafer 150 and the sealing layer 10 by the peeling layer 140 can be reduced. Note that in FIG. 4D, the peeled layer 140 after deterioration is represented as a peeled layer 140A.

  Thus, in this method, the release layer 140 is irradiated with the ultraviolet light L3 in order to reduce the adhesion between the support wafer 150 and the sealing layer 10 or the like by the release layer 140. Therefore, the exfoliation layer 140 can provide adhesion between the support wafer 150 and the sealing layer 10 and the like afterwards without using a material having low adhesion with the support wafer 150 and the sealing layer 10 or the like as the release layer 140. Since it can be lowered, a material having high adhesion to the support wafer 100, the sealing layer 10, and the like can be used as the release layer 140.

  Next, the peeling layer 140 is peeled off from the support wafer 150, and the wafer 180 made of each layer stacked above this including the peeling layer 140 is separated from the support wafer 150 (FIG. 4D).

  Next, the peeling layer 140 attached to the surface of the wafer 180 is removed to expose the surface of the chip 11 (FIG. 1). In this way, the semiconductor device 1 of the present embodiment is manufactured.

  As described above, in the method of manufacturing the semiconductor 1 according to the present embodiment, the light amount γ per unit area is smaller than the light amount α per unit area of the release layer 110 and larger than the light amount β per unit area of the adhesive layer 130. Since the ultraviolet light L1 is irradiated to the adhesive layer 130 from the support wafer 100 side through the support wafer 100 and the release layer 110, when the adhesive layer 130 is cured, a material that causes a new problem or The adhesive layer 130 can be efficiently cured without using a method or using a special material or method. Thereby, the semiconductor device 1 can be manufactured by a stable, simple and inexpensive method.

  Moreover, in the manufacturing method of the semiconductor 1 according to the present embodiment, the ultraviolet light L1 is condensed so as to irradiate the ultraviolet light L2 and L3 having the same wavelength as the ultraviolet light L1 and high amounts of light. A light source can be shared. Accordingly, the release layers 110 and 140 can be surely deteriorated without using a material or method that causes a new defect or using a special material or method. A material having high adhesion can be used. As a result, the semiconductor device 1 can be manufactured by a stable, simple and inexpensive method.

[Modification]
In the above embodiment, the wavelengths of the ultraviolet light L1 and the ultraviolet lights L2 and L3 are the same, but they may be different from each other.

For example, in FIG. 3B, using an LD-pumped YVO ₄ laser, the wavelength is 266 nm ultraviolet light that is a fourth harmonic of the LD-pumped YVO ₄ laser (ultraviolet light including a wavelength component smaller than the wavelength component of the ultraviolet light L1). ) Is collected by the lens 160, and the collected ultraviolet light L2 is swept over the surface of the support wafer 100 to irradiate the peeling layer 110. Further, for example, using an excimer laser, ultraviolet light having a wavelength of 248 nm (ultraviolet light including a wavelength component smaller than the wavelength component of the ultraviolet light L1) is condensed by the lens 160, and the condensed ultraviolet light L2 is collected. Alternatively, the surface of the support wafer 100 may be swept to irradiate the peeling layer 110.

Similarly, for example, in FIG. 4 (C), the using LD excitation YVO ₄ laser, the wavelength is focused ultraviolet light of 266nm in fourth harmonic of LD pumped YVO ₄ laser with a lens 160, it is condensed The release layer 140 is irradiated with ultraviolet light L3 by sweeping the surface of the support wafer 100. In addition, for example, using an excimer laser, ultraviolet light having a wavelength of 248 nm is condensed by the lens 160, and the condensed ultraviolet light L3 is swept over the surface of the support wafer 100 to irradiate the peeling layer 140. Also good.

  As described above, when the wavelengths of the ultraviolet light L1 and the ultraviolet lights L2 and L3 are different from each other, it is necessary to prepare a plurality of light sources. For example, it is possible to use an epoxy resin or an epoxy resin obtained by adding a curing agent.

  This epoxy resin is a resin having not only ultraviolet curable properties but also thermosetting properties, and is a resin capable of two-stage curing of ultraviolet curing and thermal curing. The epoxy resin is a resin that can be cured extremely thinly, and is a resin that can adjust the ultraviolet light transmittance by changing the thickness. Of course, any resin having the same properties as the above-described epoxy resin can be applied to the release layer 110.

  As described above, also in this modification, the peeling layers 110 and 140 can be reliably deteriorated without using a material or method that causes a new problem or using a special material or method. A material having high adhesion can be used for the release layers 110 and 140. As a result, the semiconductor device 1 can be manufactured by a stable, simple and inexpensive method.

  Although the present invention has been described with reference to the embodiment and the modifications, the present invention is not limited to the above-described embodiment and the like, and various modifications can be made.

It is sectional drawing of the semiconductor device which concerns on one embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the semiconductor device of FIG. FIG. 3 is a cross-sectional view for explaining a process following FIG. 2. It is sectional drawing for demonstrating the process following FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor device, 10, 30 ... Sealing layer, 11, 12, 31 ... Chip, 11A, 12A, 31A ... Functional surface, 13, 21, 120, 120A, 120B ... Metal layer, 20 ... Interlayer insulating film, 22 ... via, 100,150 ... support wafer, 110,110A ... peeling layer, 130,130A, 140,140A ... adhesive layer, 160 ... lens, L1, L2, L3 ... ultraviolet light.

Claims (9)

On the support substrate transparent to the ultraviolet light, after forming a release layer capable of absorbing the ultraviolet light and having the first light amount per unit area necessary for curing by the ultraviolet light irradiation, An adhesive layer that can absorb ultraviolet light on a predetermined region of the surface of the release layer and has a second light amount smaller than the first light amount, which is necessary for curing by ultraviolet light irradiation. And an arrangement step of stacking and arranging the chips in this order from the release layer side,
An irradiation step of irradiating the adhesive layer with first ultraviolet light having a light amount per unit area smaller than the first light amount and larger than the second light amount from the support substrate side through the support substrate and the release layer; A method for manufacturing a semiconductor device, comprising: The method for manufacturing a semiconductor device according to claim 1, wherein the release layer includes a resin having not only ultraviolet curable properties but also thermosetting properties. The method for manufacturing a semiconductor device according to claim 1, wherein the release layer includes an epoxy resin or an epoxy resin obtained by adding a curing agent. 4. The method of manufacturing a semiconductor device according to claim 2, wherein, in the arranging step, before the adhesive layer is laminated, the release layer is preheated and cured. 5. The adhesive layer includes a phenol resin, an epoxy resin, an alkyd resin, a polyimide resin, a novolac resin, an acrylic resin, an acrylate resin, a styrene resin, or an ABS (acrylonitrile-butadiene-styrene) resin. Semiconductor device manufacturing method. The release layer is deteriorated by irradiating the release layer with the second ultraviolet laser light of the first light quantity or more from the support substrate side through the support substrate, and then the release layer is released to remove the chip. The method for manufacturing a semiconductor device according to claim 1, further comprising: a separation step of separating from the support substrate. The method for manufacturing a semiconductor device according to claim 6, wherein, in the separation step, the surface of the support substrate is swept and the second ultraviolet laser light is applied to the release layer. The method of manufacturing a semiconductor device according to claim 6, wherein the first ultraviolet light and the second ultraviolet light include the same wavelength component. The method of manufacturing a semiconductor device according to claim 6, wherein the second ultraviolet light includes a wavelength component smaller than a wavelength component of the first ultraviolet light.

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