JP2011086779A - Resin composition, semiconductor wafer bonded body, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition that can provide a spacer that reduces warping of a semiconductor wafer bonded body when forming the semiconductor wafer bonded body by bonding a semiconductor wafer and a transparent substrate with the spacer between, and also to provide a semiconductor wafer bonded body reduced in warping and a semiconductor device. <P>SOLUTION: The resin composition is used to form a spacer 104 in a lattice form in planar view between the semiconductor wafer 101' and the transparent substrate 102. The resin composition consists of a constituent material including an alkali-soluble resin, a thermosetting resin, and a photopolymerization initiator. When bonding the semiconductor wafer 101' and the transparent substrate 102 via the spacer 104, the spacer 104 is formed substantially on the whole surface in planar view. Then, when the thickness of the semiconductor wafer 101' is reduced to 1/5, the semiconductor wafer bonded body 2000 has a warping of ≤500 μm before processing and a rate of increase of warping after processing is ≤600%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin composition, a semiconductor wafer bonded body, and a semiconductor device.

  A semiconductor device represented by a CMOS sensor, a CCD sensor, or the like, comprising: a semiconductor substrate having a light receiving portion; a spacer provided on the semiconductor substrate; and a transparent substrate bonded to the semiconductor substrate through the spacer. A semiconductor device having the same is known.

  As a method for manufacturing such a semiconductor device, a method using a photosensitive film has been proposed in order to improve the productivity of the semiconductor device (see, for example, Patent Document 1).

  Using this photosensitive film, a plurality of semiconductor devices are manufactured in a lump as follows, for example.

  First, a photosensitive film (spacer forming layer) is pasted on a semiconductor wafer provided with a plurality of light receiving portions so as to cover the semiconductor wafer.

  Next, the photosensitive film is selectively irradiated with light (exposure) and then developed to selectively leave the photosensitive film in the region surrounding each light-receiving portion on the semiconductor wafer, thereby providing a spacer. Are formed in a lattice shape.

  Next, the semiconductor wafer on which the spacer is formed and the transparent substrate are arranged to face each other with the spacer interposed therebetween, and then the semiconductor wafer and the transparent substrate are bonded via the spacer by press-bonding them. A semiconductor wafer bonded body is obtained.

  Next, the semiconductor wafer assembly is divided according to the light receiving unit provided in the semiconductor wafer, whereby a plurality of the semiconductor devices are manufactured in a lump.

  As described above, a semiconductor device is manufactured by dividing a semiconductor wafer bonded body in which a semiconductor wafer and a transparent substrate are bonded via a spacer. However, in recent years, with the downsizing and thinning of semiconductor devices. When the thickness of the semiconductor wafer is about 100 to 600 μm and the semiconductor device is further reduced in size and thickness, it is required to be reduced to about 50 μm.

  Further, in order to set such a semiconductor wafer to such a thin thickness, a back grinding process for grinding and / or polishing the surface of the semiconductor wafer opposite to the spacer is performed. There is a high possibility that the wafer is warped or the warpage is increased.

  The warped semiconductor wafer assembly is subjected to back surface processing (for example, TSV processing), dicing processing and the like after the back grinding process.

  The back surface processing step includes, for example, a step of laminating, exposing and developing a photosensitive resist.

  Therefore, when setting a semiconductor wafer bonded body to a device such as a laminator, an exposure machine, a developing machine and a dicing saw, it is necessary to put the semiconductor wafer bonded body in a magazine case and set the magazine case to the apparatus. At this time, if the warpage of the semiconductor wafer assembly is large due to the back grinding process, the semiconductor wafer assembly does not enter the magazine case, so it cannot be set in the apparatus and the process cannot be passed. appear.

  Furthermore, even if the semiconductor wafer assembly is contained in the magazine case, the semiconductor wafer assembly is transported or fixed on the stage by suction or the like in each apparatus. If the warpage of the bonded semiconductor wafer becomes large, it cannot be transported and fixed by suction, which causes a problem that backside processing and dicing cannot be performed.

JP 2008-91399 A

  An object of the present invention is to form a semiconductor wafer bonded body in which a semiconductor wafer and a transparent substrate are bonded via a spacer, the amount of warpage generated in the semiconductor wafer bonded body is reduced, and the thickness of the semiconductor wafer is reduced. To provide a resin composition capable of obtaining the spacer having a reduced warp increase rate even when the thickness is reduced, and a semiconductor wafer bonded body and a semiconductor device in which the warp size is reduced. It is in.

Such an object is achieved by the present invention described in the following (1) to (11).
(1) Used to provide a lattice-like spacer in a plan view between a semiconductor wafer and a transparent substrate, and is composed of a constituent material containing an alkali-soluble resin, a thermosetting resin, and a photopolymerization initiator. A resin composition comprising:
When the semiconductor wafer having a diameter of 8 inches and a thickness of 725 μm is joined to the transparent substrate having a diameter of 8 inches and a thickness of 350 μm via the spacer, the spacer is viewed in plan view. Then, the semiconductor wafer is formed on almost the entire surface, and then the surface of the semiconductor wafer opposite to the spacer is ground and / or polished so that the thickness of the semiconductor wafer becomes 1/5. ,
When the substrate is placed on a plane with the transparent substrate side facing down, the warp that is the maximum height of the gap formed on the surface of the plane and the transparent substrate is that before the semiconductor wafer assembly is processed. A resin composition having a size of 500 μm or less and an increase rate of warpage after processing of 600% or less.

  (2) The alkali-soluble resin contains at least one selected from the group consisting of a carboxyl group-containing epoxy acrylate, a carboxyl group-containing acrylic resin, a carboxyl group-containing epoxy resin, a (meth) acryl-modified phenol resin, and a polyamic acid. The resin composition as described in said (1).

  (3) The resin composition according to (1) or (2), wherein the thermosetting resin is an epoxy resin.

  (4) The resin composition according to any one of (1) to (3), further containing a photopolymerizable resin as the constituent material.

  (5) The resin composition according to any one of (1) to (4), wherein the spacer has an elastic modulus of 0.1 to 15 GPa at 25 ° C.

  (6) The said spacer is a resin composition in any one of said (1) thru | or (5) whose average linear expansion coefficient of 0 to 30 degreeC is 3-150 ppm / degrees C.

  (7) The resin composition according to any one of (1) to (6), wherein the spacer has a residual stress of 0.1 to 150 MPa at 25 ° C.

  (8) The said spacer is a resin composition in any one of said (1) thru | or (7) which hardened the layer comprised with the said resin composition by both photocuring and thermosetting.

  (9) The resin composition according to any one of (1) to (8), wherein the spacer has a thickness of 5 to 500 μm.

  (10) A semiconductor wafer, a spacer including a plurality of void portions arranged in a lattice shape, and a transparent substrate are laminated in this order, which is made of the resin composition according to any one of (1) to (9) above. A bonded semiconductor wafer characterized by forming a substantially circular shape.

  (11) A semiconductor device obtained by separating the semiconductor wafer assembly according to (10) above.

  According to the present invention, when a substantially circular semiconductor wafer having a diameter of 8 inches and a thickness of 725 μm is joined to a transparent substrate having a diameter of 8 inches and a thickness of 350 μm via the spacer, the spacer Is formed on substantially the entire surface in a plan view, and then the surface of the semiconductor wafer opposite to the spacer is ground and / or polished almost uniformly to give the semiconductor wafer a thickness of 1/5. When the semiconductor wafer is processed, the size is 500 μm or less before the processing of the semiconductor wafer, and the increase rate of warpage after the processing is reduced to 600% or less. In this case, it is possible to prevent the magazine case from being set in the apparatus. Further, it is possible to prevent the suction failure in the apparatus of the semiconductor wafer bonded body and to proceed the processing smoothly.

It is sectional drawing which shows an example of a semiconductor device. It is process drawing which shows an example of the manufacturing method of a semiconductor device. It is process drawing which shows an example of the manufacturing method of a semiconductor device. It is a top view of the semiconductor wafer bonded body of the present invention obtained in the manufacture process of a semiconductor device. It is a longitudinal cross-sectional view which shows the magnitude | size of the curvature of a semiconductor wafer bonded body.

  Hereinafter, the resin composition, semiconductor wafer bonded body, and semiconductor device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<Semiconductor device (image sensor)>
First, prior to describing the resin composition and semiconductor wafer bonded body of the present invention, a semiconductor device (semiconductor element) manufactured from the semiconductor wafer bonded body of the present invention will be described.

  FIG. 1 is a longitudinal sectional view showing an example of a semiconductor device manufactured from the bonded semiconductor wafer of the present invention. In the following description, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”.

  As shown in FIG. 1, a semiconductor device (light receiving device) 100 includes a base substrate 101, a transparent substrate 102 disposed to face the base substrate 101, and an individual circuit 103 including a light receiving portion formed on the base substrate 101. The spacer 104 is formed on the edge of the individual circuit 103 including the light receiving portion, and the solder bump 106 is formed on the lower surface of the base substrate 101.

  The base substrate 101 is a semiconductor substrate, and a circuit (not shown) (an individual circuit included in a semiconductor wafer described later) is provided on the semiconductor substrate.

  On the base substrate 101, an individual circuit 103 including a light receiving portion is provided. The individual circuit 103 including the light receiving unit has, for example, a configuration in which a light receiving element and a microlens array are stacked in this order from the base substrate 101 side.

  The transparent substrate 102 is disposed so as to face the base substrate 101 and has substantially the same planar dimension as that of the base substrate 101. The transparent substrate 102 is composed of, for example, an acrylic resin substrate, a polyethylene terephthalate resin (PET) substrate, a glass substrate, or the like.

  The spacer 104 directly bonds the microlens array included in the individual circuit 103 including the light receiving unit and the transparent substrate 102 at the edge thereof, and bonds the base substrate 101 and the transparent substrate 102 together. The spacer 104 forms a gap 105 between the individual circuit 103 including the individual circuit 103 (microlens array) including the light receiving unit and the transparent substrate 102.

  Since the spacer 104 is disposed at the edge of the individual circuit 103 including the light receiving unit so as to surround the center of the individual circuit 103 including the light receiving unit, the spacer 104 is included in the individual circuit 103 including the light receiving unit. The part surrounded by the light functions as a substantial light receiving part.

  Examples of the light receiving element included in the individual circuit 103 including the light receiving unit include a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS) image sensor, and the like, and the individual circuit including the light receiving unit in the light receiving element. The light received at 103 is converted into an electrical signal.

  The solder bumps 106 are electrically conductive, and are electrically connected to the wiring provided on the base substrate 101 on the lower surface and inside the base substrate 101. As a result, an electrical signal converted from light by the individual circuit 103 including the light receiving portion is transmitted to the solder bump 106.

Such a semiconductor device 100 can be manufactured as follows, for example.
2 and 3 are longitudinal sectional views for explaining a method for manufacturing a semiconductor device. In the following description, the upper side in FIGS. 2 and 3 is referred to as “upper” and the lower side is referred to as “lower”.

  [1] First, a semiconductor wafer 101 ′ is prepared in which an individual circuit 103 including a light receiving unit is provided and a plurality of individual circuits (not shown) corresponding to one semiconductor device 100 is formed.

  In the present embodiment, as shown in FIG. 2A, the individual circuit 103 including the light receiving portion formed by being electrically connected to the individual circuit provided on the semiconductor wafer 101 ′ is integrally formed. .

  [2] Next, the spacer forming layer 12 having adhesiveness is formed on the upper surface side of the semiconductor wafer 101 ′, that is, on the side where the individual circuit 103 including the light receiving portion is provided.

  The method for forming the spacer forming layer 12 is not particularly limited. For example, I: a method for transferring the spacer forming layer 12 formed on the support substrate (film) 11 onto the semiconductor wafer 101 ′, II: spacer A method of forming the spacer forming layer 12 by applying a varnish (liquid material) containing the constituent material of the forming layer 12 and then drying, III: a method of directly drawing the varnish containing the constituent material of the spacer forming layer 12, etc. Among these, it is preferable to use the method I. In the method I, if the spacer forming layer 12 to be described later is exposed through the support base 11, it is possible to effectively prevent dust and the like from adhering to the spacer forming layer 12 effectively. it can.

  Hereinafter, a case where the spacer forming layer 12 is formed on the semiconductor wafer 101 ′ using the method I will be described as an example.

  [2-1] First, as shown in FIG. 2B, a spacer forming film 1 in which a spacer forming layer 12 is provided on a support base 11 is prepared.

  In the present invention, the spacer forming layer 12 contains an alkali-soluble resin, a thermosetting resin, and a photopolymerization initiator. Such a spacer forming layer 12 has a photo-curing property in which a portion irradiated with light is cured, an alkali developability in which a portion not irradiated with light is dissolved in an alkaline liquid, and a portion irradiated with light. It has any of thermosetting properties that are further cured by heating.

  The constituent material of the resin composition constituting the spacer forming layer 12 having such characteristics will be described in detail later.

  The support base material (film) 11 is a sheet-like base material and has a function of supporting the spacer forming layer 12.

  The support base 11 is made of a light-transmitting material when the spacer formation layer 12 described below is exposed (exposure step [4]) through the support base 11. By exposing the spacer forming layer 12 with the support substrate 11 having such a configuration, in the manufacture of the semiconductor device 100, while effectively preventing dust and the like from adhering to the spacer forming layer 12 effectively, The spacer forming layer 12 can be reliably exposed.

  Examples of the material constituting the support base 11 include polyethylene terephthalate (PET), polypropylene (PP), and polyethylene (PE). Among these, it is preferable to use polyethylene terephthalate (PET) from the viewpoint of excellent balance between light transmittance and breaking strength.

  Such a spacer-forming film 1 is prepared by, for example, dissolving an alkali-soluble resin, a thermosetting resin, a photopolymerization initiator, and, if necessary, a photopolymerizable resin and other components in a solvent. Then, a spacer forming layer forming material (liquid material) is prepared, and then this liquid material is applied onto the support substrate 11, and the solvent is removed and dried at a predetermined temperature.

  The solvent used here is not particularly limited, and an inert solvent is preferably used for the constituent material of the spacer forming layer (resin composition) 12.

  Specifically, examples of the solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, DIBK (diisobutyl ketone), cyclohexanone, and DAA (diacetone alcohol), and aromatic hydrocarbons such as benzene, xylene, and toluene. , Methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, alcohols such as 1-methoxy-2-propanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl cellosolve acetate, ethyl cellosolve acetate, BCSA (butyrocellsolve acetate) Cellosolve, NMP (N-methyl-2-pyrrolidone), THF (tetrahydrofuran), DMF (dimethylformamide), DBE (dibasic acid ester), EEP (3- Tokishipuropion ethyl), DMC (dimethyl carbonate) and the like.

  Further, the content of the solvent in the spacer forming layer forming material (liquid material) is within a range in which the content of the solid component mixed with the solvent (the constituent material of the spacer forming layer 12) is about 10 to 60% by weight. Preferably it is set.

  [2-2] Next, as shown in FIG. 2C, the surface on the individual circuit 103 side including the light receiving portion of the semiconductor wafer 101 ′, and the spacer forming layer 12 (adhesion surface) of the spacer forming film 1 Are laminated together (lamination process). As a result, the spacer forming layer 12 is provided on the side of the individual circuit 103 including the light receiving portion of the semiconductor wafer 101 ′, and the support base 11 is provided on the opposite side of the semiconductor wafer 101 ′. Are pasted together.

  The spacer forming layer 12 can be bonded to the surface (upper surface) on the individual circuit 103 side including the light receiving portion of the semiconductor wafer 101 ′, for example, as follows.

  First, the spacer forming film 1 and the semiconductor wafer 101 'are aligned, and the lower surface of the spacer forming film 1 and the upper surface of the semiconductor wafer 101' are brought into contact with each other at one end side.

  Next, in this state, the spacer forming film 1 and the semiconductor wafer 101 ′ are sandwiched between a pair of rollers at a position where the lower surface of the spacer forming film 1 and the upper surface of the semiconductor wafer 101 ′ are in contact with each other. Install in the joining device. As a result, the spacer forming film 1 and the semiconductor wafer 101 'are pressurized.

  Next, the pair of rollers is moved from one end side toward the other end side. As a result, the spacer forming layer 12 is sequentially joined to the individual circuit 103 including the light receiving portion in the portion sandwiched between the pair of rollers, and as a result, the spacer forming film 1 and the semiconductor wafer 101 ′ are bonded together.

The pressure for pressurizing the spacer-forming film 1 and the semiconductor wafer 101 ′ between the pair of rollers is not particularly limited, but is preferably about 0.1 to 10 kgf / cm ² , preferably 0.2 to More preferably, it is about 5 kgf / cm ² . Thereby, the spacer formation layer 12 can be reliably affixed with respect to the separate circuit 103 containing a light-receiving part.

  The moving speed of each roller is not particularly limited, but is preferably about 0.1 to 1.0 m / min, and more preferably about 0.2 to 0.6 m / min.

  Each roller is provided with a heating means such as a heater, for example, and the spacer forming film 1 and the semiconductor wafer 101 ′ are heated at a portion sandwiched between the pair of rollers. The heating temperature is preferably about 0 to 120 ° C, and more preferably about 40 to 100 ° C.

  [3] Next, the spacer forming layer 12 formed on the semiconductor wafer 101 ′ is heated (PLB (post-laminate baking) step).

  Thereby, the spacer formation layer 12 formed on the level | step difference in the separate circuit 103 containing a light-receiving part can be flowed, and the surface of the spacer formation layer 12 can be made flatter.

  The temperature at which the spacer forming layer 12 is heated is preferably about 20 to 120 ° C, and more preferably about 30 to 100 ° C.

  The heating time is preferably about 1 to 10 minutes, and more preferably about 2 to 7 minutes.

  [4] Next, light (ultraviolet rays) is irradiated to the portion to be the spacer 104 of the spacer forming layer 12 and exposed (exposure process).

  Thereby, in the spacer formation layer 12, the part which should be the spacer 104 is selectively photocrosslinked.

  For example, as shown in FIG. 2D, the portion of the spacer forming layer 12 that is to be the spacer 104 is irradiated with light by using a mask 20 having an opening 201 corresponding to the portion to be the spacer 104. It is performed by irradiating with light.

  In this embodiment, the spacer forming layer 12 is exposed through the support base 11. If the spacer forming layer 12 is exposed to light, the spacer forming layer 12 can be reliably exposed while effectively preventing dust and the like from adhering to the spacer forming layer 12 effectively. Furthermore, if the support base material 11 is removed during the exposure of the spacer forming layer 12, the spacer forming layer 12 adheres to the mask 20, and as a result, the surface of the spacer forming layer 12 is flat. The attached spacer forming layer 12 may be reattached to the spacer forming layer 12 included in the semiconductor wafer 101 ′ to be exposed next, but the exposure of the spacer forming layer 12 is performed via the support base 11. If the configuration is used, the advantage that such problems can be effectively prevented can be obtained.

  The wavelength of light with which the spacer forming layer 12 is irradiated is preferably about 150 to 700 nm, and more preferably about 170 to 450 nm.

Further, the integrated light quantity of irradiating light is preferably in the range of about 200~3000J / cm ^2, more preferably about 300~2500J / cm ^2.

  [5] Next, the exposed spacer formation layer 12 is heated (PEB (post-exposure baking) step).

  Thereby, the portion to be the spacer 104 of the spacer forming layer 12 can be hardened more firmly, and the portion to be the spacer 104 of the spacer forming layer 12 can be more firmly bonded to the individual circuit 103 including the light receiving portion. . Furthermore, the residual stress remaining in the spacer formation layer 12 can be relaxed.

  The temperature for heating the spacer forming layer 12 is preferably about 30 to 120 ° C, more preferably about 30 to 100 ° C.

  The heating time is preferably about 1 to 10 minutes, and more preferably about 2 to 7 minutes.

  [6] Next, the exposed spacer formation layer 12 is developed using an alkaline solution (development process).

  As a result, as shown in FIG. 2E, the unexposed portion of the spacer forming layer 12 is removed (etched), and the spacer 104 in which the gap portion 105 is formed by the removed portion can be obtained. it can. That is, the spacer 104 composed of the exposed portion can be obtained.

  In addition, the resin composition of this invention has the high sensitivity with respect to the light in the said process [4], and is excellent in patterning property. Therefore, the spacer 104 having a desired shape can be easily formed in this step.

  In the present embodiment, since the support base material 11 is provided on the spacer formation layer 12, the support base material 11 is removed from the spacer formation layer 12 prior to the development of the spacer formation layer 12. .

  The pH of the alkaline solution used is preferably 9.5 or higher, and more preferably about 11.0 to 14.0. Thereby, the spacer forming layer 12 can be efficiently removed.

Examples of such an alkaline solution include an aqueous solution of an alkali metal hydroxide such as NaOH and KOH, an aqueous solution of an alkaline earth metal hydroxide such as Mg (OH) ₂ , an aqueous solution of tetramethylammonium hydroxide, Examples thereof include amide-based organic solvents such as N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMA), and these can be used alone or in combination.

  [7] Next, as shown in FIG. 3A, the transparent substrate 102 is bonded to the spacer 104 formed on the semiconductor wafer 101 '. That is, the transparent substrate 102 is bonded to the semiconductor wafer 101 ′ via the spacer 104 (bonding process).

  The bonding of the semiconductor wafer 101 ′ and the transparent substrate 102 is the same as that described when the semiconductor wafer 101 ′ and the spacer forming film 1 are bonded in the step [2-2], for example. It can be done using the method.

  [8] Next, the spacer 104 is thermally cured by heating in a state where the semiconductor wafer 101 ′ and the transparent substrate 102 are bonded together via the spacer 104 (thermosetting step).

Thereby, the spacer 104 and the transparent substrate 102 are physically joined. as a result,
Semiconductor wafer bonded body 1000 in which semiconductor wafer 101 ′ and transparent substrate 102 are bonded via spacer 104, that is, a semiconductor wafer bonded body having a plurality of gaps 105 between semiconductor wafer 101 ′ and transparent substrate 102. 1000 is obtained (see FIG. 4).

  The temperature for heating the spacer 104 is preferably about 80 to 180 ° C, and more preferably about 110 to 160 ° C. Thereby, the shape of the spacer 104 to be formed can be improved.

  [9] Next, as shown in FIG. 3B, at least one of grinding and polishing is performed on the lower surface (back surface) 111 on the opposite side of the semiconductor wafer 101 ′ where the transparent substrate 102 is bonded. (Back grinding process).

  The lower surface 111 is ground by, for example, a grinder provided in a grinding device (grinder).

  Due to the processing of the lower surface 111, the thickness of the semiconductor wafer 101 ′ differs depending on the electronic device to which the semiconductor device 100 is applied, but is usually set to about 100 to 600 μm and is applied to a smaller electronic device. Is set to about 50 μm.

  When the thickness of the semiconductor wafer 101 ′ is reduced in this way, the warpage generated in the semiconductor wafer bonded body 1000 becomes larger than that before the processing of the semiconductor wafer bonded body 1000, and the back surface processing step of the semiconductor wafer bonded body 1000, which is a post process [ 10] and the dicing process [11], the following problems occur.

  That is, the semiconductor wafer bonded body 1000 is subjected to the back surface processing step [10] and the dicing step [11] after this step [9].

  The back surface processing step [10] includes, for example, a step of laminating, exposing and developing a photosensitive resist.

  Therefore, when the semiconductor wafer bonded body 1000 is set in an apparatus such as a laminator, an exposure machine, a developing machine, and a dicing saw, it is necessary to put the semiconductor wafer bonded body 1000 in a magazine case and set the magazine case in the apparatus. However, if warpage of the semiconductor wafer bonded body 1000 is increased by performing the step [9] at this time, the semiconductor wafer bonded body 1000 does not enter the magazine case, so that the process cannot be set in the apparatus. Problems such as inability to pass.

  Further, even if the semiconductor wafer bonded body 1000 is settled in the magazine case, in each apparatus, the semiconductor wafer bonded body 1000 is transported by suction or the like, or fixed on the stage. Later, if the warpage of the semiconductor wafer bonded body 1000 becomes large, it cannot be transported and fixed by suction, so that the back surface processing step [10] and the dicing step [11] cannot be performed.

  In order to solve such a problem, in the present invention, warpage in the semiconductor wafer bonded body 1000 before processing (grinding and / or polishing) the lower surface 111 of the semiconductor wafer 101 ′ is small, and when such processing is performed. The warpage increase rate of the resulting semiconductor wafer bonded body 1000 is set to be reduced.

  Specifically, a regulating semiconductor wafer joined body 2000 for regulating the warpage size of the semiconductor wafer joined body is prepared, and the surface of the semiconductor wafer 101 ′ opposite to the spacer 104 is ground almost uniformly. Alternatively, when the semiconductor wafer 101 ′ is processed to be polished to a thickness of 1/5, before the semiconductor wafer 101 ′ is processed, the warpage of the semiconductor wafer bonded body 2000 is 500 μm or less, and The increasing rate of warpage after processing is reduced to 600% or less.

  Here, in the present invention, the semiconductor wafer bonded body 2000 includes a substantially circular semiconductor wafer 101 ′ having a diameter of 8 inches and a thickness of 750 μm, and a transparent substrate 102 having a diameter of approximately 8 inches and a thickness of 350 μm. Are joined via a spacer 104, and the spacer 104 is formed on the entire surface in plan view (see FIG. 5).

  Furthermore, the thickness of the semiconductor wafer 101 ′ is set to 1/5 by subjecting the lower surface 111 of the semiconductor wafer 101 ′ to grinding and / or polishing almost uniformly.

  Further, when the semiconductor wafer bonded body 2000 is placed on a plane with the transparent substrate 102 side down from the relationship between the linear expansion coefficient and the elastic modulus of the semiconductor wafer 101 ′, the transparent substrate 102, and the spacer 104, As shown in FIG. 5, a gap 112 is formed between the plane and the surface of the transparent substrate 102 so that the outer peripheral portion of the transparent substrate 102 is on the lower side and the central portion is on the upper side.

  In the present invention, the maximum height X of the gap 112 is referred to as a warp occurring in the semiconductor wafer bonded body 2000, and the warpage increase rate of the semiconductor wafer bonded body 2000 refers to the semiconductor wafer bonded body before the lower surface 111 is ground. Say [(B−A) / A] × 100%, where A is the warp size of 2000 and B is the warp size of the semiconductor wafer bonded body 2000 after grinding of the lower surface 111. To do.

  In such a semiconductor wafer bonded body 2000, the warpage before processing (grinding and / or polishing) is 500 μm or less, preferably 400 μm or less, more preferably about 50 to 300 μm, and the semiconductor wafer When 101 ′ has a thickness of 1/5, the increase rate of warpage in the semiconductor wafer bonded body 2000 is 600% or less, preferably 500% or less, more preferably 400% or less (excluding 0%). . By satisfying such a relationship, the warpage of the semiconductor wafer bonded body 2000 before processing is small, and the rate of increase in the warp of the semiconductor wafer bonded body 2000 after processing is also reduced. During the back surface processing step [10] and the dicing step [11] of the bonded body 1000, the semiconductor wafer bonded body 1000 does not fit in the apparatus for performing these processes, or the semiconductor wafer bonded body 1000 is caught by the apparatus and damaged. Can be suppressed or prevented accurately.

  That is, by setting the warpage of the defining semiconductor wafer bonded body 2000 for defining the warpage size of the semiconductor wafer bonded body within such a range, the warpage of the semiconductor wafer bonded body 1000 used as an actual product can be reduced. Since the size of the processing step [10] and the dicing step [11] is practically no problem, it is possible to reliably suppress or prevent the problems that occur when the steps [10] and [11] are performed. Can do.

  In the present invention, as described above, in the semiconductor wafer bonded body 2000, the warpage magnitude is 500 μm or less before the processing of the semiconductor wafer bonded body 2000, and the warp increase rate after the processing is 600% or less. As described above, a material containing an alkali-soluble resin, a thermosetting resin, and a photopolymerization initiator is used as a constituent material of the resin composition that constitutes the spacer 104 having a lattice shape in plan view.

In the present invention, in the semiconductor wafer bonded body 2000, the thickness of the spacer 104 is preferably set to about 20 to 80 μm, more preferably about 50 μm.
Further, as the transparent substrate 102, a substrate having substantially the same elastic modulus and linear expansion coefficient as that of the semiconductor wafer 101 ′ is preferably selected, and specifically, silicate glass (quartz glass), silica (quartz), or the like is used. Those composed of a silicon oxide-based material are preferably used.

  In the semiconductor wafer bonded body 2000 in which the thickness and pitch of the spacer 104 are set within such a range, and the type of the constituent material of the transparent substrate 102 is selected, the warpage size is 500 μm before the semiconductor wafer bonded body 2000 is processed. The constituent material of the resin composition constituting the spacer 104 is selected so that the rate of increase in warpage after processing is 600% or less.

  As described above, the spacer forming layer 12 composed of a resin composition containing an alkali-soluble resin, a thermosetting resin, and a photopolymerization initiator is I: a photo-curing property in which a portion irradiated with light is cured. II: Alkali developability in which a portion not irradiated with light is dissolved in an alkali developer, and III: Thermosetting property in which a portion irradiated with light is further cured by heating At the same time, IV: the warp before processing of the semiconductor wafer bonded body 2000 is 500 μm or less, and the increase rate of the warp after the processing can be ensured to be 600% or less.

  Here, the constituent material of this resin composition suitably exhibits the characteristics I to III, and as described in IV, the warpage before processing of the semiconductor wafer bonded body 2000 is 500 μm or less, and In addition, a material having a warp increase rate after processing of 600% or less is preferably selected.

Hereinafter, each constituent material of the resin composition will be described in detail.
(Alkali-soluble resin)
The resin composition (resin composition of the present invention) constituting the spacer forming layer 12 contains an alkali-soluble resin. Thereby, the spacer formation layer 12 has alkali developability.

  Examples of the alkali-soluble resin include cresol type, phenol type, bisphenol A type, bisphenol F type, catechol type, resorcinol type, pyrogallol type phenol resin having phenolic hydroxyl group, phenol aralkyl resin, hydroxystyrene resin, hydroxyl group or carboxyl. An acrylic resin obtained by polymerizing a (meth) acrylic monomer having a group, a (meth) acrylate resin such as an epoxy acrylate or urethane acrylate having a hydroxyl group or a carboxyl group, a cyclic olefin resin containing a hydroxyl group and a carboxyl group, Polyamide resin (specifically, having at least one of a polybenzoxazole structure and a polyimide structure, and having a hydroxyl group, carboxyl group, ether group or ester in the main chain or side chain. A resin having a group, a resin having a polybenzoxazole precursor structure, a resin having a polyimide precursor structure, a resin having a polyamic acid ester structure, and the like, and a combination of one or more of these. Can be used.

  As the (meth) acrylic monomer having a hydroxyl group or a carboxyl group used in an acrylic resin obtained by polymerizing the (meth) acrylic monomer having a hydroxyl group or a carboxyl group, 2-hydroxyethyl having a hydroxyl group (meta ) Acrylate, (meth) acrylic acid having a carboxyl group, and the like, and these may be radically polymerized alone, but in view of adhesiveness, heat resistance, and moisture resistance of the spacer after heat curing, (meth) acrylic (Meth) acrylate monomers such as methyl acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, acrylonitrile having a nitrile group, styrene, divinylbenzene, butadiene, etc. You may copolymerize with the monomer which has a heavy bond.

  Among these alkali-soluble resins, those having both alkali-soluble groups and double bonds that contribute to alkali development are preferably used.

  Examples of the alkali-soluble group include a hydroxyl group and a carboxyl group. The alkali-soluble group can contribute to alkali development and can also contribute to a thermosetting reaction. Moreover, alkali-soluble resin can contribute to photocuring reaction by having a double bond.

  Examples of such a resin having an alkali-soluble group and a double bond include a curable resin that can be cured by both light and heat, and specifically, for example, an acryloyl group, a methacryloyl group, and a vinyl. And a thermosetting resin having a photoreactive group such as a group, and a photocurable resin having a thermoreactive group such as a phenolic hydroxyl group, an alcoholic hydroxyl group, a carboxyl group, and an acid anhydride group.

  Note that the photocurable resin having a thermally reactive group may further have another thermally reactive group such as an epoxy group, an amino group, or a cyanate group. Specific examples of the photocurable resin having such a structure include (meth) acryl-modified phenol resin, (meth) acryl-modified bisphenol A type resin, (meth) acryloyl group-containing acrylic acid polymer, and carboxyl group-containing (epoxy). Examples include acrylate, polybenzoxazole precursor resin having a double bond, and polyimide precursor having a double bond. Further, a thermoplastic resin such as a carboxyl group-containing acrylic resin may be used.

  Among the resins having alkali-soluble groups and double bonds as described above (curable resins curable by both light and heat), (meth) acryl-modified phenol resins and (meth) acryl-modified bisphenol A type resins are used. Is preferred. If (meth) acryl-modified phenol resin or (meth) acryl-modified bisphenol A resin is used, it contains an alkali-soluble group. Instead of the solvent, it is possible to apply an alkaline developer with less environmental impact. Furthermore, by containing a double bond, the double bond contributes to the curing reaction, and as a result, the heat resistance of the resin composition can be improved. Further, by using the (meth) acryl-modified phenol resin or the (meth) acryl-modified bisphenol A resin, the warpage of the semiconductor wafer bonded body 2000 before the processing (before grinding and / or polishing) of the semiconductor wafer 101 ′ is large. The (meth) acryl-modified phenol resin is also capable of reliably reducing the warpage and reliably reducing the increase rate of warpage of the semiconductor wafer bonded body 2000 after the processing (after grinding and / or polishing) of the semiconductor wafer 101 ′. A (meth) acryl-modified bisphenol A resin is preferably used.

  Examples of (meth) acryl-modified phenol resins and (meth) acryl-modified bisphenol A resins include reacting a hydroxyl group of phenols or bisphenols with an epoxy group of a compound having an epoxy group and a (meth) acryloyl group. And (meth) acryl-modified phenolic resins and (meth) acryl-modified bisphenol A-type resins obtained.

  Specifically, examples of such a (meth) acryl-modified bisphenol A type resin include those shown in Chemical Formula 1 below.

  In addition, in the molecular chain of the (meth) acryloyl-modified epoxy resin in which a (meth) acryloyl group is introduced at both ends of the epoxy resin, the hydroxyl group in the molecular chain of the (meth) acryloyl-modified epoxy resin A compound in which a dibasic acid is introduced by bonding to one carboxyl group in the acid by an ester bond (in addition, one or more repeating units of the epoxy resin in this compound are introduced in the molecular chain) The number of dibasic acids is 1 or more). In addition, such a compound, for example, first, by reacting an epoxy group at both ends of an epoxy resin obtained by polymerizing epichlorohydrin and a polyhydric alcohol and (meth) acrylic acid, at both ends of the epoxy resin. By obtaining a (meth) acryloyl-modified epoxy resin having a (meth) acryloyl group introduced, and then reacting the hydroxyl group in the molecular chain of the obtained (meth) acryloyl-modified epoxy resin with an anhydride of a dibasic acid It is obtained by forming an ester bond with one carboxyl group of this dibasic acid.

  Here, when a thermosetting resin having a photoreactive group is used, the modification rate (substitution rate) of the photoreactive group is not particularly limited, but 20% of the total reactive groups of the resin having an alkali-soluble group and a double bond. It is preferably about -80%, more preferably about 30-70%. By setting the modification amount of the photoreactive group within the above range, a resin composition having particularly excellent resolution can be provided.

  On the other hand, when using a photocurable resin having a heat-reactive group, the modification rate (substitution rate) of the heat-reactive group is not particularly limited, but 20 to 20 to the total of reaction groups of the resin having an alkali-soluble group and a double bond. It is preferably about 80%, more preferably about 30 to 70%. By setting the modification amount of the heat-reactive group within the above range, it is possible to provide a resin composition that is particularly excellent in resolution.

  Further, when a resin having an alkali-soluble group and a double bond is used as the alkali-soluble resin, the weight average molecular weight of the resin is not particularly limited, but is preferably 30000 or less, more preferably about 5000 to 150,000. preferable. When the weight average molecular weight is within the above range, the film formability is particularly excellent when the spacer forming layer is formed on the film.

  Here, the weight average molecular weight of the alkali-soluble resin can be evaluated using, for example, GPC (gel permeation chromatography), and the weight average molecular weight can be calculated in advance using a calibration curve prepared using a styrene standard substance. In addition, tetrahydrofuran (THF) was used as a measurement solvent, and measurement was performed under a temperature condition of 40 ° C.

  Further, the content of the alkali-soluble resin in the resin composition is not particularly limited, but is preferably about 15 to 50% by weight, more preferably about 20 to 40% by weight in the entire resin composition. . In addition, when a resin composition contains the filler mentioned later, content of alkali-soluble resin is about 10 to 80 weight% among the resin components (all components except a filler) of a resin composition, Preferably, it may be about 15 to 70% by weight. If the content of the alkali-soluble resin is less than the lower limit, the effect of improving the compatibility with other components in the resin composition (for example, a photocurable resin and a thermosetting resin described later) may be reduced. If the value exceeds the upper limit, the developability or the resolution of the patterning of the spacer formed by the photolithography technique may be deteriorated. In other words, by setting the content of the alkali-soluble resin in the above range, it is possible to more reliably exhibit the function of thermocompression bonding after patterning the resin by photolithography.

(Thermosetting resin)
Moreover, the resin composition which comprises the spacer formation layer 12 contains the thermosetting resin. Thereby, even after exposure and development, the spacer forming layer 12 exhibits adhesiveness by curing. That is, after bonding the spacer forming layer 12 and the semiconductor wafer, exposing and developing, the transparent substrate 102 can be thermocompression bonded to the spacer forming layer 12.

  As the thermosetting resin, when a curable resin that can be cured by heat is used as the alkali-soluble resin described above, a resin different from the resin is selected.

  Specifically, as the thermosetting resin, for example, phenol novolak resin, cresol novolak resin, novolak type phenol resin such as bisphenol A novolak resin, phenol resin such as resol phenol resin, bisphenol A type epoxy resin, bisphenol F type Bisphenol type epoxy resin such as epoxy resin, novolak epoxy resin, novolac type epoxy resin such as cresol novolac epoxy resin, biphenyl type epoxy resin, stilbene type epoxy resin, triphenolmethane type epoxy resin, alkyl-modified triphenolmethane type epoxy resin, Triazine core-containing epoxy resin, dicyclopentadiene-modified phenolic epoxy resin, epoxy resin such as epoxy resin having naphthalene skeleton, urea (urea) resin Examples include resins having a triazine ring such as melamine resin, unsaturated polyester resins, bismaleimide resins, polyurethane resins, diallyl phthalate resins, silicone resins, resins having a benzoxazine ring, cyanate ester resins, epoxy-modified siloxanes, etc. Among them, one kind or a combination of two or more kinds can be used. Among these, it is particularly preferable to use an epoxy resin. Thereby, heat resistance and adhesiveness with the transparent substrate 102 can be further improved. Further, the warpage of the semiconductor wafer bonded body 2000 before the processing of the semiconductor wafer 101 ′ (before grinding and / or polishing) can be reliably reduced, and the semiconductor wafer bonded body 2000 after the processing of the semiconductor wafer 101 ′ can be reduced. The rate of increase in warpage can be reliably reduced.

  Furthermore, when using an epoxy resin, as an epoxy resin, use an epoxy resin that is solid at room temperature (especially a bisphenol type epoxy resin) and an epoxy resin that is liquid at room temperature (especially a silicone-modified epoxy resin that is liquid at room temperature). Is preferred. Thereby, it can be set as the spacer formation layer 12 which is excellent in both flexibility and resolution while maintaining heat resistance.

  Although content of the thermosetting resin in a resin composition is not specifically limited, It is preferable that it is about 10 to 40 weight% in this whole resin composition, and it is more preferable that it is about 15 to 35 weight%. There exists a possibility that the effect which improves the heat resistance after the thermosetting of the spacer formation layer 12 obtained as content of a thermosetting resin is less than the said lower limit may fall. Moreover, when content of a thermosetting resin exceeds the said upper limit, there exists a possibility that the effect which improves the toughness of the spacer formation layer 12 after thermosetting may fall.

  Moreover, when using an epoxy resin as mentioned above for a thermosetting resin, it is preferable to contain further the phenol novolak resin other than this epoxy resin. By adding a phenol novolac resin, the developability of the resulting spacer forming layer 12 can be improved. Furthermore, by including both an epoxy resin and a phenol novolac resin as the thermosetting resin in the resin composition, the thermosetting property of the epoxy resin is further improved, and the strength after thermosetting of the spacer 104 to be formed is increased. There is also an advantage that it can be further improved.

(Photopolymerization initiator)
The resin composition constituting the spacer forming layer 12 contains a photopolymerization initiator. Thereby, the spacer formation layer 12 can be efficiently patterned by photopolymerization.

  Examples of the photopolymerization initiator include benzophenone, acetophenone, benzoin, benzoin isobutyl ether, methyl benzoin benzoate, benzoin benzoic acid, benzoin methyl ether, benzylfinyl sulfide, benzyl, dibenzyl, diacetyl and the like.

  The content of the photopolymerization initiator in the resin composition is not particularly limited, but is preferably about 0.5 to 5% by weight in the whole resin composition, and about 0.8 to 3.0% by weight. More preferably. If the content of the photopolymerization initiator is less than the lower limit, the effect of starting photopolymerization may not be sufficiently obtained. Moreover, when content of a photoinitiator exceeds the said upper limit, reactivity will become high and there exists a possibility that a preservability and resolution may fall.

(Photopolymerizable resin)
The resin composition constituting the spacer forming layer 12 preferably contains a photopolymerizable resin in addition to the above components. Thereby, it will be contained in a resin composition with the alkali-soluble resin mentioned above, and the patterning property of the spacer formation layer 12 obtained can be improved more.

  In addition, as this photopolymerizable resin, when the curable resin which can be hardened | cured with light is used as an alkali-soluble resin mentioned above, the thing different from this resin is selected.

  Although it does not specifically limit as photopolymerizable resin, For example, (meth) acrylic compounds, such as (meth) acrylic-type monomer and oligomer which have at least 1 or more of unsaturated polyester, acryloyl group, or methacryloyl group in 1 molecule And vinyl-based compounds such as styrene. These can be used alone or in combination of two or more.

  Among these, the ultraviolet curable resin which has a (meth) acrylic-type compound as a main component is preferable. The (meth) acrylic compound is preferably used because it has a high curing rate when irradiated with light and can pattern the resin with a relatively small amount of exposure.

  Examples of the (meth) acrylic compound include acrylic acid ester or methacrylic acid ester monomers. Specific examples include ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and glycerin. Trifunctional (meth) acrylates such as di (meth) acrylate, bifunctional (meth) acrylates such as 1,10-decanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate ) Acrylate, pentaerythritol tetra (meth) acrylate, tetrafunctional (meth) acrylates such as ditrimethylolpropane tetra (meth) acrylate, hexafunctional (meth) acrylates such as dipentaerythritol hexa (meth) acrylate Etc. The.

  Among these (meth) acrylic compounds, it is preferable to use a (meth) acrylic polyfunctional monomer. Thereby, the spacer 104 after exposure and development obtained from the spacer forming layer 12 can exhibit excellent strength. As a result, the semiconductor device 100 including the spacer 104 is more excellent in shape retention. Further, by using the (meth) acrylic polyfunctional monomer, it is possible to reliably reduce the warpage of the semiconductor wafer bonded body 2000 before processing (before grinding and / or polishing) of the semiconductor wafer 101 ′, and The (meth) acrylic polyfunctional monomer is also preferably used from the viewpoint that the increase rate of warpage of the semiconductor wafer bonded body 2000 after the processing of the semiconductor wafer 101 ′ can be reliably reduced.

  In the present specification, the (meth) acrylic polyfunctional monomer means a monomer of a (meth) acrylic acid ester having a tri- or higher functional acryloyl group or methacryloyl group.

  Furthermore, among the (meth) acrylic polyfunctional monomers, it is particularly preferable to use trifunctional (meth) acrylate or tetrafunctional (meth) acrylate. Thereby, the said effect can be exhibited more notably.

  In addition, when using a (meth) acrylic polyfunctional monomer as a photopolymerizable resin, it is preferable to contain an epoxy vinyl ester resin further. Thereby, since the (meth) acrylic polyfunctional monomer and the epoxy vinyl ester resin undergo radical polymerization during the exposure of the spacer formation layer 12, the strength of the spacer 104 to be formed after exposure and development can be increased more effectively. Can do. Moreover, since the solubility with respect to the alkali developing solution of the part which is not exposed of the spacer formation layer 12 can be improved at the time of image development, the residue after image development can be reduced.

  Epoxy vinyl ester resins include 2-hydroxy-3-phenoxypropyl acrylate, Epolite 40E methacrylic adduct, Epolite 70P acrylic acid adduct, Epolite 200P acrylic acid adduct, Epolite 80MF acrylic acid adduct, Epolite 3002 methacrylic acid adduct. Epolite 3002 acrylic acid adduct, Epolite 1600 acrylic acid adduct, bisphenol A diglycidyl ether methacrylic acid adduct, bisphenol A diglycidyl ether acrylic acid adduct, Epolite 200E acrylic acid adduct, Epolite 400E acrylic acid adduct, etc. Can be mentioned.

  When the (meth) acrylic polyfunctional polymer is contained in the photopolymerizable resin, the content of the (meth) acrylic polyfunctional polymer in the resin composition is not particularly limited, but is 1 to 50 in the entire resin composition. It is preferably about% by weight, more preferably about 5% to 25% by weight. Thereby, the strength of the spacer forming layer 12 after exposure, that is, the spacer 104 can be improved more effectively, and the shape retention property when the semiconductor wafer 101 ′ and the transparent substrate 102 are bonded can be improved more effectively. be able to.

  Furthermore, when the photopolymerizable resin contains an epoxy vinyl ester resin in addition to the (meth) acrylic polyfunctional polymer, the content of the epoxy vinyl ester resin is not particularly limited. The amount is preferably about 30% by weight, more preferably about 5% to 15% by weight. Thereby, the residual rate of the foreign material remaining on each surface of the semiconductor wafer and the transparent substrate after the semiconductor wafer and the transparent substrate are attached can be more effectively reduced.

  Moreover, it is preferable that the above photopolymerizable resins are liquid at normal temperature. Thereby, the curing reactivity by light irradiation (for example, ultraviolet irradiation) can be improved more. Moreover, the mixing operation | movement with another compounding component (for example, alkali-soluble resin) can be made easy. Examples of the photopolymerizable resin that is liquid at room temperature include, for example, ultraviolet curable resins mainly composed of the (meth) acrylic compound described above.

  The weight average molecular weight of the photopolymerizable resin is not particularly limited, but is preferably 5,000 or less, more preferably about 150 to 3000. When the weight average molecular weight is within the above range, the sensitivity of the spacer forming layer 12 is particularly excellent. Furthermore, the resolution of the spacer formation layer 12 is also excellent.

  Here, the weight average molecular weight of the photopolymerizable resin can be evaluated using, for example, GPC (gel permeation chromatograph), and can be calculated using the same method as described above.

(Dissolution promoter)
The resin composition used for forming the spacer forming layer 12 may contain a dissolution accelerator. Examples of the dissolution promoter include compounds containing a hydroxyl group or a carboxyl group, and phenols or phenol resins are particularly preferable.

  By adding the phenols or phenol resins, the phenolic hydroxyl group concentration in the resin composition is increased, and the solubility in an alkali developer is improved. In addition, after acting as a solubility improver for an alkali developer, it is taken into the matrix of the cured product of the thermosetting resin, so that it is possible to suppress contamination of the transparent substrate, the semiconductor wafer, and the like to be bonded. At the same time, a decrease in heat resistance and moisture resistance can also be suppressed.

(Inorganic filler)
In addition, the resin composition used for forming the spacer forming layer 12 may contain an inorganic filler. Thereby, the strength of the spacer 104 formed by the spacer forming layer 12 can be further improved.

  However, if the content of the inorganic filler in the resin composition becomes too large, foreign matter due to the inorganic filler adheres to the semiconductor wafer 101 ′ after the development of the spacer forming layer 12, or undercut occurs. Problem arises. Therefore, the content of the inorganic filler in the resin composition is preferably 9% by weight or less in the entire resin composition.

  Further, when a (meth) acrylic polyfunctional monomer is contained as a photopolymerizable resin, after the exposure and development of the spacer 104 formed by the spacer forming layer 12 by addition of the (meth) acrylic polyfunctional monomer. Therefore, the addition of the inorganic filler into the resin composition can be omitted.

  Examples of inorganic fillers include fibrous fillers such as alumina fibers and glass fibers, potassium titanate, wollastonite, aluminum borate, acicular magnesium hydroxide, acicular fillers such as whiskers, talc, and mica. , Sericite, glass flake, flake graphite, plate-like filler such as plate-like calcium carbonate, spherical filler such as calcium carbonate, silica, fused silica, calcined clay, unfired clay, zeolite, silica gel And the like, and the like. These may be used alone or in combination. Among these, it is particularly preferable to use a porous filler.

  Although the average particle diameter of an inorganic filler is not specifically limited, It is preferable that it is about 0.01-90 micrometers, and it is more preferable that it is about 0.1-40 micrometers. When the average particle diameter exceeds the upper limit, there is a risk that the appearance of the spacer forming layer 12 may be abnormal or the resolution may be poor. Further, if the average particle diameter is less than the lower limit value, there is a risk of poor adhesion when the spacer 104 is heated and pasted to the transparent substrate 102.

  The average particle size can be evaluated using, for example, a laser diffraction particle size distribution analyzer SALD-7000 (manufactured by Shimadzu Corporation).

  Moreover, when using a porous filler as an inorganic filler, it is preferable that the average hole diameter of this porous filler is about 0.1-5 nm, and it is more preferable that it is about 0.3-1 nm.

  Here, by setting the resin composition to include the above-described constituent materials, the spacer 104 made of this resin composition has an elastic modulus at 25 ° C., preferably about 0.1 to 15 GPa, More preferably, it may be about 1 to 7 GPa. If the elastic modulus of the spacer 104 is within this range, the warpage of the semiconductor wafer bonded body 2000 before processing (before grinding and / or polishing) of the semiconductor wafer 101 ′ can be reduced to 500 μm or less, and the semiconductor wafer The increase rate of the warp of the semiconductor wafer bonded body 2000 after processing 101 ′ can be made 600% or less.

  The elastic modulus at 25 ° C. is measured, for example, using a dynamic viscoelastic device (TA Instruments, RSA3) from −30 to 200 ° C. at a temperature rising rate of 5 ° C./min and a frequency of 10 Hz. It can be determined by reading the elastic modulus at ° C.

  Moreover, by setting the resin composition to include the above-described constituent materials, the spacer 104 composed of the resin composition has an average coefficient of linear expansion within the range of 0 ° C. to 30 ° C., preferably 20 About 150 ppm / ° C, more preferably about 50-100 ppm / ° C. If the linear expansion coefficient of the spacer 104 is within such a range, the warpage of the semiconductor wafer bonded body 2000 before processing (before grinding and / or polishing) of the semiconductor wafer 101 ′ can be reduced to 500 μm or less, and the semiconductor The increase rate of warpage of the semiconductor wafer bonded body 2000 after the processing of the wafer 101 ′ can be reduced to 600% or less.

  The average linear expansion coefficient at 0 to 30 ° C. is, for example, a measurement sample using a TMA apparatus (manufactured by Seiko Instruments Inc., TMA / SS6000, EXSTAR6000) at −30 to 150 ° C. and a heating rate of 5 ° C./min. The average linear expansion coefficient of 0 to 30 ° C. can be obtained from the dimensional change amount of 0 to 30 ° C. and the dimension before measurement of the measurement sample.

  Furthermore, since the resin composition includes the above-described constituent materials, the elastic modulus and the linear expansion coefficient can be set within the above-described ranges in the spacer 104 made of the resin composition. The residual stress at 25 ° C. is preferably about 0.1 to 150 MPa, more preferably about 0.1 to 100 MPa. If the residual stress of the spacer 104 is within such a range, the warpage of the semiconductor wafer bonded body 2000 before processing (before grinding and / or polishing) of the semiconductor wafer 101 ′ can be reduced to 500 μm or less, and the semiconductor wafer The increase rate of the warp of the semiconductor wafer bonded body 2000 after processing 101 ′ can be made 600% or less.

Residual stress at 25 ° C. is, for example, by first forming a resin resin layer on an 8 inch bare silicon wafer (in the case of a resin film, laminating and attaching. In the case of a liquid resin, heat drying after spin coating, or Printing), exposure is performed under conditions of a wavelength of 365 nm and 1000 mj / cm ² , and then thermosetting is performed at 180 ° C. for 2 hours to prepare a sample for evaluation. Next, using a surface roughness shape measuring apparatus (Tokyo Seimitsu, SURFCOM 1400D), the warpage is measured, and the residual stress can be obtained from the following formulas (1) and (2).

R = (a ² + 4X ² ) / 8X (1)
σ = [D ² E / {6Rt (1-υ)}] × 9.8 (2)
[Wherein, X is the warp size [mm], a is the measurement length [mm], R is the radius of curvature [mm], the thickness of the bare silicon wafer [mm], E is the elastic modulus of silicon (16200 kg / mm ² ), t represents the thickness [mm] of the resin layer, υ represents the Poisson's ratio (0.3), and σ represents the residual stress [MPa]. ]

  Note that this step [9] of processing (grinding and / or polishing) the lower surface 111 of the semiconductor wafer 101 'may be performed prior to the thermosetting step [8].

  [10] Next, the lower surface (back surface) 111 of the ground and / or polished semiconductor wafer 101 ′ is processed (back surface processing step).

  Examples of such processing include formation of wiring on the lower surface 111 and connection of solder bumps 106 as shown in FIG.

  [11] Next, a plurality of semiconductor devices are obtained by separating the semiconductor wafer assembly 1000 into individual circuits formed on the semiconductor wafer 101 ′, that is, corresponding to the respective gaps 105 included in the spacer 104. 100 is obtained (dicing step).

  For example, the semiconductor wafer bonded body is separated from the transparent substrate 102 side by first using a dicing saw to make a cut 21 corresponding to the position where the spacer 104 is formed, and then from the semiconductor wafer 101 ′ side. It is performed by making a cut corresponding to the cut 21 with a dicing saw.

Through the steps as described above, the semiconductor device 100 can be manufactured.
In this way, by separating the semiconductor wafer bonded body 1000 into a single piece and obtaining a plurality of semiconductor devices 100 in a lump, the semiconductor devices 100 can be mass-produced and productivity can be improved. Can do.

  In addition, the semiconductor device 100 is mounted on a support substrate having a patterned wiring, for example, via a solder bump 106, whereby the wiring provided in the support substrate and the wiring formed on the lower surface of the base substrate 101 are provided. Are electrically connected through the solder bumps 106.

  In addition, the semiconductor device 100 can be widely applied to electronic devices such as a mobile phone, a digital camera, a video camera, and a small camera while being mounted on the support substrate.

  In the present embodiment, the PLB process [3] for heating after the formation of the spacer formation layer 12 and the PEB process [5] for heating after the exposure of the spacer formation layer 12 have been described. The process can be omitted depending on the type of the resin composition (resin composition of the present invention) constituting the spacer forming layer 12.

  Alternatively, the semiconductor wafer bonded body 1000 may be heated after the back grinding process [9] for grinding the back surface 111 of the semiconductor wafer 101 '. If the semiconductor wafer bonded body 1000 is heated after the back grinding process [9], the residual stress remaining in the spacer 104 can be reliably relaxed, and the warpage of the semiconductor wafer bonded body 1000 can be accurately determined. Can be reduced.

  As mentioned above, although the resin composition, semiconductor wafer bonded body, and semiconductor device of this invention were demonstrated, this invention is not limited to these.

  For example, in the resin composition of the present invention, in addition to the above-described constituent materials, other constituent materials may be included within a range that does not impair the object of the present invention. Examples of such other constituent materials include: , Plastic resins, leveling agents, antifoaming agents and coupling agents.

Next, specific examples of the present invention will be described.
[1] Manufacture of Semiconductor Wafer Assembly Five semiconductor wafer assemblies of each Example and Comparative Example were manufactured as follows.

Example 1
1. Synthesis of alkali-soluble resin (methacryl-modified bisphenol A novolak resin: MPN001) Methyl ethyl ketone (MEK, containing 60% by weight of novolak bisphenol A resin (manufactured by Dainippon Ink & Chemicals, "Phenolite LF-4871") as a solid content Daishin Chemical Co., Ltd.) solution (500 g) was put into a 2 L flask, and tributylamine (1.5 g) as a catalyst and hydroquinone (0.15 g) as a polymerization inhibitor were added thereto and heated to 100 ° C. To this, 180.9 g of glycidyl methacrylate was added dropwise over 30 minutes, and the mixture was reacted with stirring at 100 ° C. for 5 hours to obtain a methacryl-modified bisphenol A novolak resin (methacryloyl modification rate 50%) having a solid content of 74%.

2. Preparation of resin varnish containing resin composition constituting spacer forming layer 30.0% by weight of solid content of (meth) acrylic modified bis A novolak resin (MPN001) as alkali-soluble resin, and thermosetting resin (epoxy resin) ) Cresol novolac type epoxy resin (Dainippon Ink Chemical Co., Ltd., “Epiclon N-665”) 19.0% by weight and siloxane-modified epoxy resin (Toray Dow Corning Silicone, “BY16-115”) 5.0% by weight, 10.0% by weight of ethylene glycol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., “NK Ester A-200”) as a photopolymerizable resin, and spherical silica (electrochemical industry) as an inorganic filler (SFP-20M, average particle size: 0.33 μm, maximum particle size: 0.8 μm) 35.0 wt% Weighed, to these further added methyl ethyl ketone (MEK, manufactured Daishinkagaku Co.), finally the resin component concentration of the resin varnish obtained was adjusted to 71 wt%. And it stirred until the bisphenol A novolak-type epoxy resin (Epiclon N-665) melt | dissolved.

  Next, silica was dispersed using a bead mill (bead diameter 400 μm, treatment speed 6 g / s, 5 passes).

  Next, 1.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.

3. Production of Spacer-Forming Film First, a polyester film (manufactured by Mitsubishi Plastics, “MRX50”, thickness 50 μm) was prepared as a supporting substrate.

  Next, the resin varnish prepared as described above is applied onto the supporting substrate with a comma coater (manufactured by Yurai Seiki Co., Ltd., “Model No. MFG No. 194001 type3-293”), thereby forming a coating film composed of the resin varnish. Formed. Then, the film for spacer formation was obtained by drying the formed coating film on 80 degreeC and the conditions for 20 minutes, and forming a spacer formation layer. In the obtained spacer forming film, the average thickness of the spacer forming layer was 50 μm.

4). Manufacture of warped measurement semiconductor wafer assembly First, an approximately circular semiconductor wafer having a diameter of 8 inches (Si wafer, diameter: 20.3 cm, thickness: 725 μm) was prepared.

Next, using the roll laminator, the spacer forming film manufactured above was laminated on the semiconductor wafer under the conditions of a roll temperature of 60 ° C., a roll speed of 0.3 m / min, and a syringe pressure of 2.0 kgf / cm ^2. A semiconductor wafer with a spacer forming film was obtained.

Next, after the spacer forming film is exposed to the entire surface in a plan view by irradiating the semiconductor wafer with the spacer forming film from the spacer forming film side with ultraviolet rays (wavelength 365 nm, integrated light quantity 700 mJ / cm ² ), The support substrate was removed.

  Next, a transparent substrate (quartz glass substrate, diameter 20.3 cm, thickness 350 μm) is prepared. ) Was used to produce a bonded semiconductor wafer in which the semiconductor wafer and the transparent substrate were bonded via a spacer.

5). Manufacture of Semiconductor Wafer Assembly First, an approximately 8 inch diameter semiconductor wafer (Si wafer, diameter 20.3 cm, thickness 725 μm) was prepared.

Next, using the roll laminator, the spacer forming film manufactured above was laminated on the semiconductor wafer under the conditions of a roll temperature of 60 ° C., a roll speed of 0.3 m / min, and a syringe pressure of 2.0 kgf / cm ^2. A semiconductor wafer with a spacer forming film was obtained.

Next, by irradiating the semiconductor wafer with the spacer forming film through the mask with ultraviolet rays (wavelength 365 nm, integrated light quantity 700 mJ / cm ² ) from the spacer forming film side, the spacer forming layer is latticed in a plan view. After exposure to a shape, the supporting substrate was peeled off. In the exposure of the spacer forming layer, 50% of the spacer forming layer was exposed in plan view so that the width of the exposed portion exposed in a grid pattern was 0.6 mm.

  Next, a 2.38 w% tetramethylammonium hydroxide (TMAH) aqueous solution is used as a developing solution (alkaline solution), and the spacer formation layer after exposure is developed under conditions of a developing solution pressure of 0.3 MPa and a developing time of 90 seconds. As a result, a spacer having a protrusion width (pitch) of 0.6 mm was formed on the semiconductor wafer.

  Next, a transparent substrate (quartz glass substrate, diameter 20.3 cm, thickness 350 μm) is prepared. ) Was used to produce a bonded semiconductor wafer in which the semiconductor wafer and the transparent substrate were bonded via a spacer. The transparent substrate side of the obtained semiconductor wafer bonded body was set to the lower side, the semiconductor wafer bonded body was placed on a flat surface, and the warpage before processing was measured.

6). Back Grinding of Semiconductor Wafer Assembly The semiconductor wafer of the semiconductor wafer assembly was ground with a grinder (“DFG8540” manufactured by DISCO) so that the thickness of the central portion of the semiconductor wafer was 145 μm. Further, the semiconductor wafer assembly after grinding was placed on a flat surface with the transparent substrate side of the semiconductor wafer assembly down, and the warpage after processing was measured.

7). Dicing of Semiconductor Wafer The ground semiconductor wafer bonded body was separated into a size of 7 mm × 8 mm with a dicing saw (manufactured by DISCO, DFD6450).

  In this semiconductor wafer bonded body, the spacer had an elastic modulus at 25 ° C. of 7.8 GPa, an average linear expansion coefficient from 0 ° C. to 30 ° C. was 68 ppm / ° C., and a residual stress at 25 ° C. was 16 MPa. It was.

(Example 2)
A semiconductor wafer bonded body was manufactured in the same manner as in Example 1 except that the adjustment of the resin varnish (step 2) was performed as follows.

  40.0 wt% of the solid content of the (meth) acryl-modified bis-A novolak resin (MPN001) as an alkali-soluble resin, and a cresol novolac-type epoxy resin (Dainippon Ink & Chemicals, Inc.) as a thermosetting resin (epoxy resin). , “Epiclon N-665”) 19.0 wt%, siloxane-modified epoxy resin (Toray Dow Corning Silicone, “BY16-115”) 3.0 wt% and phenol novolac resin (Sumitomo Bakelite, “ PR-HF-6 ") 2.0% by weight, and as a photopolymerizable resin, ethylene glycol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.," NK Ester A-200 ") 10.0% by weight, Silica (SFP-20M, manufactured by Denki Kagaku Kogyo Co., Ltd., average particle size: 0.33 μm, maximum particle size: 0 as an inorganic filler .8 μm) 25.0 wt%, and methyl ethyl ketone (MEK, manufactured by Daishin Chemical Co., Ltd.) is further added to these, and the resin component concentration in the finally obtained resin varnish is 71 wt%. It adjusted so that it might become. And it stirred until the bisphenol A novolak-type epoxy resin (Epiclon N-665) melt | dissolved.

  Next, silica was dispersed using a bead mill (bead diameter 400 μm, treatment speed 6 g / s, 5 passes).

  Next, 1.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.

  In the obtained semiconductor wafer bonded body, the elastic modulus at 25 ° C. of the spacer is 3.0 GPa, the average linear expansion coefficient from 0 ° C. to 30 ° C. is 70 ppm / ° C., and the residual stress at 25 ° C. is 16 MPa. Met.

(Example 3)
A semiconductor wafer bonded body was manufactured in the same manner as in Example 1 except that the adjustment of the resin varnish (step 2) was performed as follows.

  As the alkali-soluble resin, the solid content of 55.0% by weight of the (meth) acryl-modified bis-A novolak resin (MPN001), and as the thermosetting resin (epoxy resin), a cresol novolac type epoxy resin (Dainippon Ink Chemical Industries, Ltd.) , “Epiclon N-665”) 15.0 wt%, siloxane-modified epoxy resin (Toray Dow Corning Silicone, “BY16-115”) 5.0 wt% and phenol novolac resin (Sumitomo Bakelite, “ PR-HF-6 ") 7.0% by weight and 17.0% by weight of trimethylolpropane trimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.," NK Ester A-TMP ") as a photopolymerizable resin. In addition, methyl ethyl ketone (MEK, manufactured by Daishin Chemical Co., Ltd.) is further added to these, and finally obtained. Resin component concentration in fat varnish was adjusted to 71 wt%. And it stirred until the bisphenol A novolak-type epoxy resin (Epiclon N-665) melt | dissolved.

  Next, 1.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.

  In the obtained semiconductor wafer bonded body, the elastic modulus of the spacer at 25 ° C. is 2.4 GPa, the average linear expansion coefficient from 0 ° C. to 30 ° C. is 84 ppm / ° C., and the residual stress at 25 ° C. is 18 MPa. Met.

Example 4
A semiconductor wafer bonded body was manufactured in the same manner as in Example 1 except that the adjustment of the resin varnish (step 2) was performed as follows.

  As the alkali-soluble resin, the solid content of the (meth) acryl-modified bis A novolak resin (MPN001) is 45.0% by weight, and as the thermosetting resin (epoxy resin), a cresol novolak type epoxy resin (Dainippon Ink & Chemicals, Inc.) is used. , “Epiclon N-665”) 27.0% by weight, siloxane-modified epoxy resin (manufactured by Dow Corning Toray, “BY16-115”) 3.0% by weight, and tetramethylol as a photopolymerizable resin Methane tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., “NK Ester A-TMMT”) was weighed 23.0% by weight, and methyl ethyl ketone (MEK, manufactured by Daishin Chemical Co., Ltd.) was further added to these. The resin component concentration in the obtained resin varnish was adjusted to 71% by weight. And it stirred until the bisphenol A novolak-type epoxy resin (Epiclon N-665) melt | dissolved.

  Next, 2.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.

  In the obtained semiconductor wafer bonded body, the elastic modulus of the spacer at 25 ° C. is 5.1 GPa, the average linear expansion coefficient from 0 ° C. to 30 ° C. is 95 ppm / ° C., and the residual stress at 25 ° C. is 63 MPa. Met.

(Example 5)
A semiconductor wafer bonded body was manufactured in the same manner as in Example 1 except that the adjustment of the resin varnish (step 2) was performed as follows.

  As the alkali-soluble resin, the solid content of the (meth) acryl-modified bis A novolak resin (MPN001) is 45.0% by weight, and as the thermosetting resin (epoxy resin), a cresol novolak type epoxy resin (Dainippon Ink & Chemicals, Inc.) is used. , “Epiclon N-665”) 30.0 wt%, siloxane-modified epoxy resin (manufactured by Dow Corning Toray, “BY16-115”) 8.0 wt%, and tetramethylol as a photopolymerizable resin Weigh 15.0% by weight of methane tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., “NK Ester A-TMMT”), and add methyl ethyl ketone (MEK, manufactured by Daishin Chemical Co., Ltd.) to these. The resin component concentration in the obtained resin varnish was adjusted to 71% by weight. And it stirred until the bisphenol A novolak-type epoxy resin (Epiclon N-665) melt | dissolved.

  Next, 2.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.

  In the obtained semiconductor wafer bonded body, the elastic modulus at 25 ° C. of the spacer is 4.5 GPa, the average linear expansion coefficient from 0 ° C. to 30 ° C. is 91 ppm / ° C., and the residual stress at 25 ° C. is 32 MPa. Met.

(Example 6)
A semiconductor wafer bonded body was manufactured in the same manner as in Example 1 except that the adjustment of the resin varnish (step 2) was performed as follows.

  As the alkali-soluble resin, the solid content of the (meth) acryl-modified bis A novolak resin (MPN001) is 45.0% by weight, and as the thermosetting resin (epoxy resin), a cresol novolak epoxy resin (manufactured by Dainippon Ink & Chemicals, Inc.). , “Epiclon N-665”) 30.0 wt%, siloxane-modified epoxy resin (manufactured by Toray Dow Corning Silicone, “BY16-115”) 8.0 wt%, and photopolymerizable resin dipenta Weigh 15.0% by weight of erythritol hexaacrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light Acrylate DPE-6A”), and add methyl ethyl ketone (MEK, manufactured by Daishin Chemical Co., Ltd.) to these. It adjusted so that the resin component density | concentration in the obtained resin varnish might be 71 weight%. And it stirred until the bisphenol A novolak-type epoxy resin (Epiclon N-665) melt | dissolved.

  Next, 2.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.

  In addition, in the obtained semiconductor wafer bonded body, the elastic modulus at 25 ° C. of the spacer is 3.8 GPa, the average linear expansion coefficient from 0 ° C. to 30 ° C. is 89 ppm / ° C., and the residual stress at 25 ° C. is 43 MPa. Met.

(Example 7)
A semiconductor wafer bonded body was manufactured in the same manner as in Example 1 except that the adjustment of the resin varnish (step 2) was performed as follows.

  As the alkali-soluble resin, the solid content of the (meth) acryl-modified bis A novolak resin (MPN001) is 45.0% by weight, and as the thermosetting resin (epoxy resin), a cresol novolak type epoxy resin (Dainippon Ink & Chemicals, Inc.) is used. , “Epiclon N-665”) 30.0% by weight, siloxane-modified epoxy resin (manufactured by Toray Dow Corning Silicone, “BY16-115”) 8.0% by weight, and photopolymerizable resin, ethylene glycol Weigh 15.0% by weight of dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., “NK Ester A-200”), and add methyl ethyl ketone (MEK, manufactured by Daishin Chemical Co., Ltd.) to these. The resin component concentration in the resulting resin varnish was adjusted to 71% by weight. And it stirred until the bisphenol A novolak-type epoxy resin (Epiclon N-665) melt | dissolved.

  Next, 2.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.

  In the obtained semiconductor wafer bonded body, the elastic modulus at 25 ° C. of the spacer is 1.4 GPa, the average linear expansion coefficient from 0 ° C. to 30 ° C. is 93 ppm / ° C., and the residual stress at 25 ° C. is 23 MPa. Met.

(Example 8)
A semiconductor wafer bonded body was manufactured in the same manner as in Example 1 except that the adjustment of the resin varnish (step 2) was performed as follows.

  As the alkali-soluble resin, the solid content of the (meth) acryl-modified bis A novolak resin (MPN001) is 20.0% by weight, and as the thermosetting resin (epoxy resin), a cresol novolak type epoxy resin (Dainippon Ink & Chemicals, Inc.) is used. , “Epiclon N-665”) 14.0% by weight and siloxane-modified epoxy resin (manufactured by Dow Corning Silicone, “BY16-115”) 3.0% by weight; Methacrylate (made by Shin-Nakamura Chemical Co., Ltd., “NK Ester A-200”) 7.0% by weight and spherical silica as an inorganic filler (Electric Chemical Industries, SFP-20M, average particle size: 0.33 μm, maximum) Weighed 55.0% by weight (particle size: 0.8 μm), and in addition to these, methyl ethyl ketone (MEK, large It was added Chemical Co.), and finally the resin component concentration of the resin varnish obtained was adjusted to 71 wt%. And it stirred until the bisphenol A novolak-type epoxy resin (Epiclon N-665) melt | dissolved.

  Next, silica was dispersed using a bead mill (bead diameter 400 μm, treatment speed 6 g / s, 5 passes).

Next, 1.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.
In addition, in the obtained semiconductor wafer bonded body, the elastic modulus at 25 ° C. of the spacer is 9.9 GPa, the average linear expansion coefficient from 0 ° C. to 30 ° C. is 49 ppm / ° C., and the residual stress at 25 ° C. is 9 MPa. Met.

Example 9
A semiconductor wafer bonded body was manufactured in the same manner as in Example 1 except that the adjustment of the resin varnish (step 2) was performed as follows.

  As the alkali-soluble resin, the solid content of the (meth) acryl-modified bis-A novolak resin (MPN001) is 25.0% by weight, and as the thermosetting resin (epoxy resin), a cresol novolak type epoxy resin (Dainippon Ink & Chemicals, Inc.) is used. , “Epiclon N-665”) 16.0% by weight, and siloxane-modified epoxy resin (manufactured by Toray Dow Corning Silicone, “BY16-115”) 4.0% by weight; Methacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., “NK Ester A-200”) 8.0 wt% and spherical silica (SFP-20M, manufactured by Denki Kagaku Kogyo Co., Ltd., average particle size: 0.33 μm, maximum) Weighed 45.0% by weight (particle size: 0.8 μm), and in addition to these, methyl ethyl ketone (MEK, large It was added Chemical Co.), and finally the resin component concentration of the resin varnish obtained was adjusted to 71 wt%. And it stirred until the bisphenol A novolak-type epoxy resin (Epiclon N-665) melt | dissolved.

  Next, silica was dispersed using a bead mill (bead diameter 400 μm, treatment speed 6 g / s, 5 passes).

Next, 2.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.
In the obtained semiconductor wafer bonded body, the elastic modulus of the spacer at 25 ° C. is 8.5 GPa, the average linear expansion coefficient from 0 ° C. to 30 ° C. is 60 ppm / ° C., and the residual stress at 25 ° C. is 11 MPa. Met.

(Comparative Example 1)
A semiconductor wafer bonded body was manufactured in the same manner as in Example 1 except that the adjustment of the resin varnish (step 2) was performed as follows.

  The solid content of 35.0% by weight of the (meth) acryl-modified bis-A novolak resin (MPN001) as the alkali-soluble resin, and dipentaerythritol hexaacrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light Acrylate DPE-6A”) as the photopolymerizable resin ] 63.0 wt% is weighed, and methyl ethyl ketone (MEK, manufactured by Daishin Chemical Co., Ltd.) is further added to these, and the resin component concentration in the finally obtained resin varnish becomes 71 wt%. Adjusted as follows.

  Next, 2.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.

  In the obtained semiconductor wafer bonded body, the elastic modulus of the spacer at 25 ° C. is 5.2 GPa, the average linear expansion coefficient from 0 ° C. to 30 ° C. is 118 ppm / ° C., and the residual stress at 25 ° C. is 107 MPa. Met.

(Comparative Example 2)
A semiconductor wafer bonded body was manufactured in the same manner as in Example 1 except that the adjustment of the resin varnish (step 2) was performed as follows.

  45.0% by weight of the solid content of the (meth) acryl-modified bis-A novolak resin (MPN001) as the alkali-soluble resin, and dipentaerythritol hexaacrylate (manufactured by Kyoeisha Chemical Co., Ltd., “Light Acrylate DPE-6A”) as the photopolymerizable resin. ”) Weigh out 53.0% by weight, and further add methyl ethyl ketone (MEK, manufactured by Daishin Chemical Co., Ltd.), and the resin component concentration in the finally obtained resin varnish becomes 71% by weight. Adjusted as follows.

  Next, 2.0% by weight of benzyldimethyl ketal (manufactured by Ciba Specialty Chemicals, “Irgacure 651”) is added as a photopolymerization initiator, and the resin varnish is stirred for 1 hour with a stirring blade (450 rpm). Got.

  In addition, in the obtained semiconductor wafer bonded body, the elastic modulus at 25 ° C. of the spacer is 5.0 GPa, the average linear expansion coefficient from 0 ° C. to 30 ° C. is 101 ppm / ° C., and the residual stress at 25 ° C. is 90 MPa. Met.

  In addition, Table 1 shows the content (% by weight) of various constituent materials contained in the resin composition constituting the spacer forming layer in each example and comparative example.

[2] Evaluation of warpage of semiconductor wafer bonded body First, the semiconductor wafer bonded bodies of the examples and comparative examples were heated at 150 ° C. for 90 minutes to thermally cure the spacers included in the semiconductor wafer bonded body. It was.

  Next, with respect to the semiconductor wafer bonded bodies of the examples and comparative examples, the size of the warp after the spacer was thermally cured using a surface roughness meter (manufactured by Tokyo Seimitsu Co., Ltd., “surfcom 1400D-64”), respectively. Was measured.

  Next, about the semiconductor wafer joined body of each Example and Comparative Example, by grinding the lower surface (back surface) of the semiconductor wafer using a grinding apparatus (“DFG8540” manufactured by DISCO), the central portion of the semiconductor wafer The thickness was 145 μm. That is, the thickness of the semiconductor wafer was set to 1/5. Then, the warpage of the bonded semiconductor wafer after grinding (back grinding) was measured in the same manner as described above.

  Table 2 below shows the magnitudes of warpage of the semiconductor wafer bonded bodies of the respective examples and comparative examples before and after back grinding, which were measured as described above.

  In addition, the magnitude | size of the curvature of the semiconductor wafer conjugate | zygote of each Example and a comparative example is an average value of the measured value each measured with five semiconductor wafer conjugate | zygote.

[3] Evaluation of Back Grinding Property of Semiconductor Wafer Assembly In each example and each comparative example, 5. 5. The semiconductor wafer bonded body obtained in the above 6. The back grindability of the bonded semiconductor wafer after back grinding (grinding) was evaluated as follows.

  That is, about the semiconductor wafer bonded body after back grinding obtained in each example and each comparative example, the thickness of arbitrary 10 points of the semiconductor wafer was measured, and the back grinding property was evaluated according to the following evaluation criteria.

A: The thickness variation (maximum-minimum) of the semiconductor wafer after grinding is less than 10 μm.
A: The thickness variation of the semiconductor wafer after grinding is 10 to 30 μm (no problem in practical use).
X: The thickness variation of the semiconductor wafer after grinding is larger than 30 μm.

[4] Dicing property of semiconductor wafer In each example and each comparative example, 5. And 6. The semiconductor wafer bonded body after back grinding (grinding) through The dicing property was evaluated as follows for the bonded semiconductor wafer assembly in FIG.

A: The yield of singulation was 95% or more.
A: The yield of singulation was 90 to less than 95%.
X: Due to the warpage of the semiconductor wafer bonded body, it was impossible to carry it by the suction jig.

Table 2 shows the evaluation results of various evaluations [2] to [4] carried out as described above.
Furthermore, from the magnitude | size of the curvature of the semiconductor wafer bonded body of each Example and comparative example which were shown in Table 2, about the semiconductor wafer bonded body of each Example and comparative example, after the back grind from the semiconductor wafer bonded body before the back grind The rate of increase in warpage of the bonded semiconductor wafer was determined.
The results are also shown in Table 2 below.

  As is apparent from Table 2, in the semiconductor wafer bonded body of each example, the warpage before back grinding was reduced to 500 μm or less, and the increase rate of warpage after back grinding was reduced to 600% or less. The results are obtained.

On the other hand, in the semiconductor wafer bonded body of Comparative Example 1, the warp size before back grinding exceeded 500 μm and could not be set in the back grinding apparatus.
Moreover, in the semiconductor wafer bonded body of Comparative Example 2, the rate of increase in warpage after back grinding exceeded 600%, and the dicing apparatus could not be transported by the suction jig.

  From the above, by using a resin composition used for providing the spacer, which is composed of a constituent material containing an alkali-soluble resin, a thermosetting resin, and a photopolymerization initiator, it is possible to bond a semiconductor wafer. It has been clarified that the size of the warp of the body can be reduced to 500 μm or less, and the increase rate of the warp after back grinding can be reduced to 600% or less.

  Then, the semiconductor wafer bonded body can be efficiently ground by reducing the warp size of the semiconductor wafer bonded body to 500 μm or less and reducing the increase rate of the warp after back grinding to 600% or less. It was found that it can be separated into individual pieces with higher yield.

DESCRIPTION OF SYMBOLS 1 Spacer formation film 11 Support base material 12 Spacer formation layer 100 Semiconductor device 101 Base board | substrate 101 'Semiconductor wafer 102 Transparent substrate 103 Individual circuit 104 including a light-receiving part Spacer 105 Cavity part 106 Solder bump 111 Lower surface 112 Cavity 20 Mask 201 Opening part 21 Notches 1000, 2000 Semiconductor wafer bonded body

Claims (11)

Resin that is used to provide a spacer in the form of a lattice in a plan view between a semiconductor wafer and a transparent substrate, and is composed of a constituent material containing an alkali-soluble resin, a thermosetting resin, and a photopolymerization initiator A composition comprising:
When the semiconductor wafer having a diameter of 8 inches and a thickness of 725 μm is joined to the transparent substrate having a diameter of 8 inches and a thickness of 350 μm via the spacer, the spacer is viewed in plan view. Then, the semiconductor wafer is formed on almost the entire surface, and then the surface of the semiconductor wafer opposite to the spacer is ground and / or polished so that the thickness of the semiconductor wafer becomes 1/5. ,
When the substrate is placed on a plane with the transparent substrate side facing down, the warp that is the maximum height of the gap formed on the surface of the plane and the transparent substrate is that before the semiconductor wafer assembly is processed. A resin composition having a size of 500 μm or less and an increase rate of warpage after processing of 600% or less.   2. The alkali-soluble resin contains at least one selected from the group consisting of a carboxyl group-containing epoxy acrylate, a carboxyl group-containing acrylic resin, a carboxyl group-containing epoxy resin, a (meth) acryl-modified phenol resin, and a polyamic acid. The resin composition described in 1.   The resin composition according to claim 1, wherein the thermosetting resin is an epoxy resin.   The resin composition according to any one of claims 1 to 3, further comprising a photopolymerizable resin as the constituent material.   The resin composition according to any one of claims 1 to 4, wherein the spacer has an elastic modulus of 0.1 to 15 GPa at 25 ° C.   6. The resin composition according to claim 1, wherein the spacer has an average linear expansion coefficient of 0 to 30 ° C. of 3 to 150 ppm / ° C. 6.   The resin composition according to any one of claims 1 to 6, wherein the spacer has a residual stress of 0.1 to 150 MPa at 25 ° C.   The resin composition according to any one of claims 1 to 7, wherein the spacer is obtained by curing a layer composed of the resin composition by both photocuring and thermosetting.   The resin composition according to claim 1, wherein the spacer has a thickness of 5 to 500 μm.   A substantially circular shape in which a semiconductor wafer, a spacer comprising a plurality of gaps arranged in a lattice shape, and a transparent substrate are laminated in this order, which is made of the resin composition according to any one of claims 1 to 9. A semiconductor wafer bonded structure characterized by comprising:   A semiconductor device obtained by separating the semiconductor wafer bonded body according to claim 10 into individual pieces.

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