JP2018519655A - Device substrate and semiconductor device manufacturing method - Google Patents

Abstract

A device substrate manufacturing method and a semiconductor device manufacturing method capable of easily removing a metal oxide formed on at least one surface of a metal concave portion and a convex portion on a wafer surface. A temporary surface containing a thermoplastic resin and a compound containing a fluorine atom on the surface of the wafer having at least one of a concave portion and a convex portion, the main component of which is copper, on the surface having at least one of the concave portion and the convex portion. Applying an adhesive composition to form a temporary adhesive layer, applying a carrier on the temporary adhesive layer opposite to the surface in contact with the wafer to form a laminate, and A method for producing a device substrate, comprising: heating a laminated body at a temperature exceeding 170 ° C., then peeling the carrier, and further peeling the temporary adhesive. [Selection] Figure 3

Description

  The present invention relates to a device substrate manufacturing method and a semiconductor device manufacturing method. In particular, the present invention relates to a method for manufacturing a device substrate, characterized in that a temporary adhesive is used to fix a wafer and reduce the thickness.

  Conventionally, in manufacturing a semiconductor device substrate, it has been studied to reduce the thickness of the substrate. As a wafer such as a silicon wafer used in a semiconductor device manufacturing process, a wafer having a thickness of about 700 to 900 μm is widely known. In recent years, attempts have been made to reduce the thickness of a wafer to 200 μm or less in order to reduce the size of an integrated circuit (IC) chip. However, since a wafer having a thickness of 200 μm or less is very thin and, as a result, a semiconductor device manufacturing member based on the wafer is also very thin, such a member may be further processed, or It is difficult to support the member stably and without damaging when the member is simply moved.

  In order to solve the above problems, for example, as shown in Patent Document 1 (Japanese Patent Laid-Open No. 2014-189731), a technique using a temporary adhesive has been studied. Specifically, a description will be given with reference to FIG. As shown in FIG. 4A, a protective layer 71 is provided on the surface of the wafer 60 before being thinned, in which metal convex portions 62 called bumps and pillars are provided on the surface of the substrate portion 61 of the wafer. Separately from the wafer 60 provided with the protective layer 71, the temporary adhesive layer 11 is provided on the surface of the carrier 12, and the adhesive carrier 100 is formed. The protective layer 71 side of the wafer 60 provided with the protective layer 71 and the temporary adhesive layer 11 side of the adhesive carrier 100 are bonded together. As shown in (C), the wafer 60 is thinned. The protective layer 71 is dissolved with a solvent, and the thinned wafer 62 and the adhesive carrier 100 are separated to obtain the thinned wafer 60. By such means, the thin film can be appropriately formed.

JP 2014-189731 A

  By the way, the surface of the metal convex portion or concave portion of the wafer may lose its metallic luster due to natural oxidation or the like during processing. Such oxidation of the surface of the convex portion or the concave portion reduces the conductivity of the wafer, so it is desirable to remove it. However, in order to remove the metal oxide, a separate process is required, which is troublesome.

Means for Solving the Invention

  The present invention has been made to solve the above-mentioned problems, and a device substrate capable of easily removing a metal oxide formed on the surface of a metal protrusion or recess on the wafer surface. It is an object to provide a method, a method for manufacturing a semiconductor device, and use of a temporary adhesive composition.

  Based on the above-mentioned problems, the present invention has been studied by the present invention, and as a result, a temporary adhesive composition containing a thermoplastic resin and a compound containing a fluorine atom was used and heated at a temperature exceeding 170 ° C. It has been found that the metal oxide can be removed together with the temporary adhesive by peeling the agent from the wafer. Specifically, the above problem has been solved by the following means <1>, preferably <2> to <16>.

<1> A temporary adhesive composition containing a thermoplastic resin and a compound containing a fluorine atom is applied onto a carrier to form a temporary adhesive layer, which is on the temporary adhesive layer and is opposite to the carrier Applying a wafer having copper as a main component to the surface on the side and having at least one of a concave portion and a convex portion so that the side having at least one of the concave portion and the convex portion is in contact with the temporary adhesive layer to form a laminate, Or
Temporary adhesive composition containing a compound containing a thermoplastic resin and a fluorine atom on the surface having at least one of the concave and convex portions of the wafer having copper as a main component and at least one of the concave and convex portions. To form a temporary adhesive layer, to form a laminate on the temporary adhesive layer by applying a carrier on the side opposite to the surface in contact with the wafer,
A method for producing a device substrate, comprising: heating the laminated body at a temperature exceeding 170 ° C., separating a carrier from the laminated body, and further peeling a temporary adhesive.

<2> The method for producing a device substrate according to <1>, wherein the thermoplastic resin is an elastomer.

<3> The method for producing a device substrate according to <2>, wherein the elastomer has a 5% thermal mass reduction temperature of 250 ° C. or higher, which is increased from 25 ° C. at 20 ° C./min.

<4> The method for producing a device substrate according to <2> or <3>, wherein the elastomer includes a repeating unit derived from styrene.

<5> The method for producing a device substrate according to any one of <2> to <4>, wherein the elastomer is a block copolymer in which one end or both ends are styrene.

<6> The method for producing a device substrate according to any one of <1> to <5>, wherein the compound containing a fluorine atom further contains a lipophilic group.

<7> The method for producing a device substrate according to any one of <1> to <6>, wherein the compound containing a fluorine atom is liquid at 25 ° C.

<8> X of the surface of the temporary adhesive layer measured by irradiating a monochromatic AlKα ray at 25 W with respect to an analysis area range of 1400 μm × 700 μm on the surface of the temporary adhesive layer and detecting at an extraction angle of 45 ° The abundance ratio of fluorine atoms using line photoelectron spectroscopy, the abundance ratio of fluorine atoms on the carrier-side surface of the temporary adhesive layer and the abundance ratio of fluorine atoms on the wafer-side surface of the temporary adhesive layer The method for producing a device substrate according to any one of <1> to <7>, in which at least one of is from 10 to 35%.

<9> The method for producing a device substrate according to any one of <1> to <8>, wherein the temporary adhesive layer is liquid at 25 ° C. and includes a compound containing a silicon atom.

<10> The method for producing a device substrate according to any one of <1> to <9>, wherein the carrier and the temporary adhesive layer are adjacent to each other.

<11> The device substrate according to any one of <1> to <10>, wherein the laminate is heated and then subjected to at least one of a mechanical treatment and a chemical treatment on a wafer side surface of the laminate. Method.

<12> The method for producing a device substrate according to any one of <1> to <11>, wherein the temporary adhesive after peeling includes copper oxide.

<13> The method for producing a device substrate according to any one of <1> to <12>, comprising peeling the temporary adhesive layer at an angle of 60 ° to 180 ° with respect to the substrate surface of the wafer.

<14> The wafer has two or more rectangular semiconductor chips including at least one of a concave portion and a convex portion, and two opposite sides of the rectangular semiconductor chip are opposite to another rectangular semiconductor chip. <1> to <13>, wherein the temporary adhesive layer is peeled off from an angle of more than 30 ° and less than 60 ° with respect to one side of the rectangular shape. The manufacturing method of the device board | substrate in any one of.

<15> A method for manufacturing a semiconductor device, including the method for manufacturing a device substrate according to any one of <1> to <14>.

<16> Use of a temporary adhesive composition containing a thermoplastic resin and a compound containing a fluorine atom for removing copper oxide on at least one surface of a convex portion and a concave portion mainly composed of copper on a wafer surface.

  1a to 1g are schematic views showing a method for manufacturing a device substrate of the present invention.

  FIG. 2 is a schematic view showing an angle when the temporary adhesive layer is peeled from the wafer.

  FIG. 3 is an image diagram illustrating a process of removing copper oxide when the temporary adhesive layer is peeled off from the convex portion.

  FIG. 4 is a schematic view showing a conventional device substrate manufacturing method.

Detailed Description of the Invention

  Hereinafter, the present invention will be described in detail. In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value. First, terms used in this specification will be explained.

  The angle in this specification is intended to allow an error of about ± 0.5 ° in addition to a strict angle in a mathematical sense.

In the method for producing a device substrate of the present invention, a temporary adhesive composition containing a thermoplastic resin and a compound containing a fluorine atom is applied on a carrier to form a temporary adhesive layer, and the temporary adhesive layer is formed on the temporary adhesive layer. A wafer having a metal (preferably copper) as a main component on the surface opposite to the carrier and having at least one of a concave portion and a convex portion, and a side having at least one of the concave portion and the convex portion on a temporary adhesive layer To form a laminated body, or to have at least one of the concave and convex portions of the wafer having metal (preferably copper) as a main component and at least one of the concave and convex portions on the surface. A temporary adhesive layer containing a thermoplastic resin and a compound containing a fluorine atom is applied to the surface on the side to form a temporary adhesive layer, which is on the temporary adhesive layer and is in contact with the wafer On the opposite side Applying a carrier to form a laminated body, heating the laminated body at a temperature exceeding 170 ° C., separating the carrier from the laminated body, and further peeling the temporary adhesive. And
By heating a temporary adhesive composition containing a thermoplastic resin and a compound containing a fluorine atom at a temperature exceeding 170 ° C., the anchor effect works and the adhesion of the temporary adhesive composition to the wafer is improved. As a result, a metal oxide (preferably copper oxide) formed by natural oxidation on the surface of at least one of the concave portion and convex portion (hereinafter sometimes referred to as “convex portion and / or concave portion”) and the convex portion of the wafer. And / or the adhesive strength between the copper oxide and the temporary adhesive becomes higher than the adhesive strength between the recesses, and the metal oxide (preferably the copper oxide is preferable) when the temporary adhesive (preferably the temporary adhesive layer) is peeled off. ) With the temporary adhesive. Until now, when removing the metal oxide (preferably, copper oxide), a separate process has been provided, but the present invention can eliminate such a process. Further, in the present invention, when the temporary adhesive composition contains a compound containing a fluorine atom, the compound containing a fluorine atom is unevenly distributed in the surface layer of the temporary adhesive layer. The wafer and the temporary adhesive layer can be easily peeled off without using a mold layer or the like.

  Hereinafter, the method of the present invention will be described in detail with reference to FIGS. It goes without saying that the present invention is not limited to these embodiments.

  1-3, 1 is a wafer, 2 is a substrate part of the wafer, 3 is a convex part and / or a concave part, 4 is a carrier, 5 is a temporary adhesive layer, 6 is a support, 7 is The semiconductor chip, 8 is copper oxide, and 22 is a thinned wafer.

  FIG. 1 is a schematic view showing a device substrate manufacturing method of the present invention.

  As shown in FIG. 1a, the wafer 1 has a convex portion and / or a concave portion 3 and the like mainly composed of metal (preferably copper) on the surface of the substrate portion 2 of the wafer. Here, having a metal as a main component means that the most abundant component among the constituent components of the convex portion and / or the concave portion is a metal, and 90% by mass or more of the constituent components of the convex portion and / or the concave portion, Furthermore, it is preferable that 95 mass% or more is a metal (preferably copper). Further, as shown in FIG. 1a, in the present invention, a carrier 4 that supports the wafer 1 is used.

  Here, the convex part and / or the concave part is, for example, a bump or a pillar. Of course, the protrusions and / or recesses may be other metal protrusions and / or recesses without departing from the spirit of the present invention.

  The material of the substrate portion of the wafer is not particularly defined, and examples thereof include silicon, mold resin (such as epoxy resin), and a mixed substrate of mold resin and silicon. The material of the carrier is not particularly defined, and examples thereof include a silicon substrate, a ceramic substrate, a mold substrate, and a glass substrate.

  Next, as shown in FIG. 1 b, the temporary adhesive layer 5 is formed by applying the temporary adhesive composition on the carrier 4. As a method of applying the temporary adhesive composition on the carrier 4, the application or temporary adhesive composition is formed into a film and laminated. As the coating method, spin coating, spray coating, and roll coating are more preferable. When a temporary adhesive composition contains a solvent, it is preferable to dry, after applying a temporary adhesive composition to a layer form. Drying conditions vary depending on the type of the temporary bonding composition and the film thickness of the temporary bonding film. Drying conditions are preferably 60 to 220 ° C. and 10 to 600 seconds, for example. The drying temperature is more preferably 80 to 200 ° C. The drying time is more preferably 30 to 500 seconds, still more preferably 40 to 400 seconds. Drying may be carried out by increasing the temperature stepwise in two steps. For example, heating at 90 to 130 ° C. for 30 seconds to 250 seconds and then heating at 170 to 220 ° C. for 30 seconds to 250 seconds can be mentioned.

  In FIG. 1 b, the temporary adhesive composition is provided on the surface of the carrier 4. However, another layer may be provided on the surface of the carrier 4 and the temporary adhesive layer 5 may be formed on the surface. Examples of other layers include a release layer and a separation layer. In the present invention, an embodiment in which the temporary adhesive layer 5 is provided on the surface of the carrier 4 is preferable.

  Moreover, in FIG. 1b, although the temporary adhesive composition is applied on a carrier, the aspect which applies a temporary adhesive composition to the surface of the side which has a convex part and / or a recessed part of a wafer may be sufficient. In the present invention, it is preferable to apply on a carrier.

  Further, as shown in FIG. 1c, a wafer having a convex part and / or a concave part 3 mainly composed of a metal (preferably copper) and / or a concave part on the surface has the convex part and / or the concave part 3 or the like. The laminate is formed by applying the side so as to be in contact with the temporary adhesive layer 5. At this time, it can manufacture preferably by heat-pressing a wafer, a carrier, and a temporary adhesive layer. The pressure bonding conditions are preferably, for example, a temperature of 100 to 230 ° C., a pressure of 0.01 to 1 MPa, and a time of 1 to 15 minutes.

  Moreover, when a temporary adhesive layer is applied to the surface of the wafer, a carrier is applied to the side opposite to the surface in contact with the wafer on the temporary adhesive layer to form a laminate. In this case, the temporary adhesive layer and the carrier may be adjacent to each other or other layers may be interposed therebetween. Examples of other layers include a release layer and a separation layer.

  As a more preferred embodiment of the present invention, a temporary adhesive layer 5 is provided on the surface of the carrier 4 and bonded to the wafer. Further, the temporary adhesive layer may be one layer or two or more layers, but is preferably one layer.

  After the heating, as shown in FIG. 1d (22 in FIG. 1d), the substrate portion 2 of the wafer, that is, the side opposite to the side in contact with the temporary adhesive layer 5 of the wafer is thinned. Thinning is achieved by performing at least one of mechanical treatment and chemical treatment. The mechanical processing and chemical processing characteristics are not particularly limited. For example, thinning processing such as grinding and chemical mechanical polishing (CMP), chemical vapor deposition (CVD), physical vapor deposition (PVD), etc. It is preferable to perform treatment under high temperature and vacuum, treatment using chemicals such as organic solvent, acidic treatment solution and basic treatment solution, plating treatment, irradiation with actinic rays, heating / cooling treatment and the like.

  The thickness after thinning of the substrate portion of the wafer is preferably less than 500 μm in average thickness, and more preferably 1 to 200 μm.

  Next, the laminate shown in FIG. 1d is heated at a temperature in excess of 170.degree. The lower limit of the heating temperature is preferably 175 ° C. or higher, more preferably 180 ° C. or higher, preferably higher than 180 ° C., and more preferably 185 ° C. or higher. The upper limit value of the heating temperature is more preferably 300 ° C. or less. By setting it as such a range, the metal oxide (preferably copper oxide) formed in the surface of the said convex part can be removed more effectively.

  The heating time is preferably 30 seconds or more, more preferably 1 minute or more, and further preferably 30 minutes or more after reaching the heating temperature. The upper limit value of the heating time is not particularly defined, but is preferably 5 hours or less, more preferably 1 hour or less after reaching the heating temperature.

  In this embodiment, after the wafer substrate is thinned, heating is performed at a temperature exceeding 170 ° C. However, the substrate portion of the wafer may be thinned after heating at a temperature exceeding 170 ° C.

After heating, as shown in FIG. 1e, the carrier 4 is separated from the laminate. As a means for separation, separation may be performed by applying force, or separation may be performed by providing a release layer or separation layer as described above. Examples of the release layer and the separation layer include a layer that is dissolved by a solvent and a layer that is separated by irradiation with light. In the present invention, it is preferable to separate by applying force. That is, it is preferable to pull up from the end of the carrier 4 in the vertical direction with respect to the thinned wafer 22 and perform separation without any processing. At this time, it is also preferable that the gap between the carrier 4 and the temporary adhesive layer 5 is cut with a knife or the like and then separated. In the present invention, the separation interface is preferably separated at the interface between the carrier 4 and the temporary adhesive layer 5. That is, it is preferable that the separation strength A at the interface between the carrier 4 and the temporary adhesive layer 5 and the separation strength B between the surface having the convex portion and / or the concave portion of the wafer and the temporary adhesive layer 5 satisfy the following expressions. .
A <B Formula (1)
The speed at the time of separation is preferably 30 to 70 mm / min, and more preferably 40 to 60 mm / min.
The separation is preferably performed at 40 ° C. or lower, more preferably 10 to 40 ° C.

  After separating the carrier 4 from the laminate, the thinned wafer 22 having the temporary adhesive layer 5 on the surface is preferably moved to the support 6 as shown in FIG. Examples of the support 6 include a dicing tape and a back grind tape. However, it goes without saying that subsequent steps may be performed without moving to the support 6 or the like.

  Next, as shown in FIG. 1g, the temporary adhesive layer 5 is peeled from the thinned wafer 22 having the temporary adhesive layer 5 on the surface. The means for peeling is not particularly limited, and can be performed by a machine or by hand. Peeling is preferably performed at 40 ° C. or lower, more preferably 10 to 40 ° C.

  Further, in FIG. 1g, the temporary adhesive is shown as a layer, but it goes without saying that the temporary adhesive is not necessarily peeled off in a layered state and is included in the scope of the present invention.

  Peeling is preferably performed by peeling the temporary adhesive layer 5 at an angle of 60 ° to 180 ° (angle α in FIG. 1g) with respect to the substrate surface of the wafer. By peeling at such an angle, it is possible to peel well with a small force. Moreover, it becomes easy to peel a temporary adhesive agent layer in a layered state. Examples of the peeling means include peeling by hand, peeling by a machine, and the like. The peeling force may be 10 to 135 N, for example, depending on the bonding conditions and the like. The lower limit value of the peeling angle α is preferably 90 ° or more. The upper limit value of the angle α is preferably 150 ° or less.

  Incidentally, the thinned wafer 22 used in the present invention normally has two or more rectangular semiconductor chips 7 including at least one of a concave portion and a convex portion, as shown in FIG. That is, the convex portion exists in the semiconductor chip 7. The two opposing sides of the rectangular semiconductor chip are preferably arranged so as to be parallel to the two opposing sides of the other rectangular semiconductor chip. Here, in this invention, it is preferable to peel a temporary adhesive bond layer from the angle of more than 30 degrees and less than 60 degrees with respect to the said rectangular one side. That is, it is preferable to peel from the direction of the angle β in FIG. Here, the arrow in a figure has shown the direction which peels a temporary adhesive layer. By peeling the temporary adhesive layer from such a direction, the temporary adhesive can be peeled with a small peeling force. Moreover, it becomes easy to peel a temporary adhesive agent layer in a layered state.

  The peeling angle is more preferably 40 ° or more and 50 ° or less with respect to one side of the rectangular semiconductor chip. The rectangular shape is intended to include an error in a range allowed in the technical field of the present invention in addition to a rectangular shape in a mathematical sense. The rectangular shape includes a square shape, and a square shape is more preferable.

  FIG. 3 is a schematic view showing how copper oxide is peeled off, and FIG. 3A shows a state in which a film of copper oxide 8 is formed on the surface of the convex portion 3 of the wafer 22 which has been thinned. In FIG. 3A, a film of copper oxide 8 is shown, but it is not necessary to be a complete film, and copper may be partially oxidized. As shown in FIG. 3B, in the present invention, the temporary adhesive layer 5 is formed on the surface of the convex portion 3 in a state where the film of the copper oxide 8 is formed. Then, the temporary adhesive layer 5 is heated at a temperature exceeding 170 ° C., whereby an anchor effect works and adhesion between the convex portion 3 and the copper oxide 8 film is improved. The temporary adhesive penetrates into the fine irregularities of the copper oxide by applying heat, and the adhesion between the copper oxide and the temporary adhesive layer becomes larger than the adhesion between the copper oxide and the convex portion. This is called the anchor effect. As a result, the copper oxide 8 can be effectively peeled when the temporary adhesive layer 5 is peeled (FIG. 3C).

  The device substrate obtained by the above method is then diced and incorporated into a semiconductor device, for example, for each of the rectangular semiconductor chips. That is, the present invention also discloses a semiconductor device manufacturing method including the device substrate manufacturing method.

  Next, the temporary adhesive composition used in the present invention will be described.

  The temporary adhesive composition used in the present invention includes a thermoplastic resin and a compound containing a fluorine atom.

  Since the temporary adhesive composition used in the present invention contains a compound containing a fluorine atom, the compound containing a fluorine atom tends to be unevenly distributed in the surface layer of the temporary adhesive layer, and the concentration of the compound containing a fluorine atom in the surface layer of the temporary adhesive layer Can be increased. For this reason, the temporary adhesive layer excellent in the peelability with respect to a wafer can be formed. Moreover, the temporary adhesive layer which was excellent in adhesiveness can be formed by a heating process, following the fine unevenness | corrugation of a carrier and a wafer, and the moderate anchor effect.

  Specifically, the surface area of 1400 μm × 700 μm of the surface of the temporary adhesive layer is irradiated with 25 W of monochromatic AlKα ray and detected at a take-off angle of 45 °, and the abundance ratio of fluorine atoms on the surface is measured. And it is preferable that at least one of the fluorine atom existing ratio on the carrier side surface of the temporary adhesive layer and the fluorine atom existing ratio on the wafer side surface of the temporary adhesive layer is 10 to 35%, More preferably, it is 15 to 30%.

<< Compound containing fluorine atom >>
The temporary adhesive composition used in the present invention contains a compound containing a fluorine atom. The compound containing a fluorine atom is preferably a fluorine-based liquid compound defined as a liquid at 25 ° C. According to the present invention, the fluorinated liquid compound has a viscosity of 1 mPa × s to 100,000 mPa × s at 25 ° C. The viscosity at 25 ° C. of the compound containing a fluorine atom is more preferably 10 mPa × s to 20,000 mPa × s, and further preferably 100 mPa × s to 15,000 mPa × s.

  In the present invention, the compound containing a fluorine atom can be preferably used in any form of an oligomer or a polymer. Moreover, the mixture of an oligomer and a polymer may be sufficient. Such a mixture may further contain a monomer. The compound containing a fluorine atom may be a monomer.

The compound containing a fluorine atom is preferably an oligomer, a polymer, or a mixture thereof from the viewpoint of heat resistance and the like.
Examples of the oligomer and polymer include a radical polymer, a cationic polymer, and an anionic polymer, and any of them can be preferably used. A vinyl polymer is particularly preferred.

  In the present invention, the compound containing a fluorine atom is preferably a compound that is not denatured during processing of a wafer or carrier used for temporary adhesion. For example, a compound that can exist in a liquid state even after heating at 250 ° C. or higher or processing a wafer with various chemicals is preferable. As a specific example, the viscosity at 25 ° C. after heating to 25 ° C. from a temperature of 25 ° C. under a temperature rising condition of 10 ° C./min is 1 to 100,000 mPa · s. It is preferably 10 to 20,000 mPa · s, more preferably 100 to 15,000 mPa · s.

  The compound containing a fluorine atom having such characteristics is preferably a non-thermosetting compound having no reactive group. The reactive group here refers to all groups that react by heating at 250 ° C., and examples thereof include a polymerizable group and a hydrolyzable group. Specifically, for example, a meta (acrylic) group, an epoxy group, an isocyanato group, and the like can be given.

  Further, the compound containing a fluorine atom preferably has a 10% thermal mass decrease temperature of 250 ° C. or higher, more preferably 280 ° C. or higher. Moreover, although an upper limit does not have limitation in particular, For example, 1000 degrees C or less is preferable and 800 degrees C or less is more preferable. According to this aspect, it is easy to form a temporary adhesive layer having excellent heat resistance. In addition, mass decreasing temperature is a value measured on the said temperature rising conditions in nitrogen stream by the thermogravimetry apparatus (TGA).

  The compound containing a fluorine atom used in the present invention preferably has a lipophilic group. Examples of the lipophilic group include linear or branched alkyl groups, cycloalkyl groups, and aromatic groups.

  The compound containing a fluorine atom may be a compound containing only one kind of lipophilic group, or may contain two or more kinds. The lipophilic group may contain a fluorine atom. That is, the compound containing a fluorine atom in the present invention may be a compound in which only the lipophilic group contains a fluorine atom. In addition to the lipophilic group, a compound further having a group containing a fluorine element (also referred to as a fluorine group) may be used. Preferably, it is a compound containing a lipophilic group and a fluorine group. When the compound containing a fluorine atom is a compound having a lipophilic group and a fluorine group, the lipophilic group may or may not contain a fluorine atom, but preferably does not contain a fluorine atom.

  The compound containing a fluorine atom has one or more lipophilic groups in one molecule, preferably 2 to 100, particularly preferably 6 to 80.

  As the fluorine group, a known fluorine group can be used. Examples thereof include a fluorine-containing alkyl group and a fluorine-containing alkylene group. Of the fluorine groups, those that function as lipophilic groups are included in the lipophilic groups.

  The compound containing a fluorine atom preferably has a fluorine atom content of 1 to 90% by mass, more preferably 2 to 80% by mass, and still more preferably 5 to 70% by mass. When the fluorine content is in the above range, the peelability is excellent.

  The content of fluorine atoms is defined as “{(number of fluorine atoms in one molecule × mass of fluorine atoms) / mass of all atoms in one molecule} × 100”.

  As a suitable example of the compound containing the fluorine atom marketed, Megafac (registered trademark) F-251, F-281, F-477, F-552, F-553, and F-554 manufactured by DIC Corporation are available. F-555, F-556, F-557, F-558, F-559, F-560, F-561, F-562, F-563, F-565, F-567, F-568, F -569, F-571, R-40, R-41, R-43, and R-94.

  The content of the compound containing a fluorine atom in the temporary adhesive composition used in the present invention is preferably 0.01 to 10% by mass relative to the mass of the temporary adhesive composition excluding the solvent. 02-5 mass% is more preferable. If content of the compound containing a fluorine atom is the said range, it will be excellent in adhesiveness and peelability. The compound containing a fluorine atom may be used alone or in combination of two or more. When using 2 or more types together, it is preferable that total content is the said range.

<< Elastomer >>
The thermoplastic resin contained in the temporary adhesive composition used in the present invention is preferably an elastomer. By using the elastomer, it is possible to form a temporary adhesive layer having excellent adhesiveness by following the convex part and / or concave part of the wafer and having an appropriate anchor effect. In addition, when separating the carrier from the thinned wafer or peeling the temporary adhesive from the thinned wafer, it can be properly separated and peeled without applying stress to the thinned wafer. It is possible to prevent damage and peeling of the semiconductor chip and the like.

  In addition, in this specification, an elastomer represents the high molecular compound which shows elastic deformation. That is, when an external force is applied, the polymer compound is defined as a polymer compound that has the property of instantly deforming according to the external force and recovering the original shape in a short time when the external force is removed.

  The weight average molecular weight of the elastomer is preferably 2,000 to 200,000, more preferably 10,000 to 200,000, and even more preferably 50,000 to 100,000. By being in this range, the solubility of the elastomer in the solvent will be excellent, and the coatability will be improved.

  In the present invention, the elastomer is not particularly limited, and examples thereof include a block copolymer, a random copolymer, and a graft copolymer, and a block copolymer is preferable.

  The types of elastomer include elastomers containing repeating units derived from styrene (polystyrene elastomers), polyester elastomers, polyolefin elastomers, polyurethane elastomers, polyamide elastomers, polyacryl elastomers, silicone elastomers, polyimide elastomers, and the like. Can be used. In particular, polystyrene-based elastomers, polyester-based elastomers, and polyamide-based elastomers are preferable, and polystyrene-based elastomers are most preferable from the viewpoints of heat resistance and peelability.

  In the present invention, the elastomer is preferably a hydrogenated product. In particular, a hydrogenated product of a polystyrene-based elastomer is preferable. When the elastomer is a hydrogenated product, thermal stability and storage stability are improved. Furthermore, the peelability is improved. The hydrogenated product means a polymer having a structure in which an elastomer is hydrogenated.

  The elastomer preferably has a 5% thermal mass decrease temperature of 25 ° C. raised at 20 ° C./min, preferably 250 ° C. or more, more preferably 300 ° C. or more, and further preferably 350 ° C. or more. Preferably, the temperature is 400 ° C. or higher. Moreover, although an upper limit does not have limitation in particular, For example, 1000 degrees C or less is preferable and 800 degrees C or less is more preferable. According to this aspect, it is easy to form a temporary adhesive layer having excellent heat resistance.

  The elastomer used in the present invention can be deformed to 200% with a small external force at room temperature (20 ° C.) when the original size is 100%, and 130% in a short time when the external force is removed. It preferably has the property of returning to the following.

<<< Polystyrene Elastomer >>>
There is no restriction | limiting in particular as a polystyrene-type elastomer, According to the objective, it can select suitably. For example, styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-butadiene-butylene-styrene. Copolymer (SBBS) and hydrogenated products thereof, styrene-ethylene-butylene styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene- Examples include styrene block copolymers.

  As for content of the repeating unit derived from styrene in a polystyrene-type elastomer, 10-90 mass% is preferable. From the viewpoint of peelability, the lower limit is preferably 25% by mass or more, and more preferably 51% by mass or more.

  The polystyrene elastomer is preferably a block copolymer of styrene and another resin, more preferably a block copolymer of styrene at one or both ends, and a block copolymer of styrene at both ends. It is particularly preferred. When one end or both ends of the polystyrene-based elastomer is a styrene block copolymer (a repeating unit derived from styrene), the thermal stability tends to be further improved. This is because a repeating unit derived from styrene having high heat resistance is present at the terminal. In particular, the block part of the repeating unit derived from styrene is preferably a reactive polystyrene hard block, which tends to be more excellent in heat resistance and chemical resistance. Moreover, when these are made into a block copolymer, it is thought that phase-separation by a hard block and a soft block is performed at 200 degreeC or more. The shape of the phase separation is considered to contribute to the suppression of surface roughness of the substrate portion of the wafer. In addition, such a resin is more preferable from the viewpoint of solubility in a solvent and resistance to a resist solvent.

  When the polystyrene elastomer is a hydrogenated product, stability against heat is improved, and degradation such as decomposition and polymerization hardly occurs. Furthermore, it is more preferable from the viewpoint of solubility in a solvent and resistance to a resist solvent.

  The amount of unsaturated double bonds in the polystyrene elastomer is preferably less than 15 mmol, more preferably less than 5 mmol, and less than 0.5 mmol per gram of the polystyrene elastomer from the viewpoint of peelability after the heating step. Most preferably. In addition, the amount of unsaturated double bonds here does not include the unsaturated double bond in the benzene ring derived from styrene. The amount of unsaturated double bonds can be calculated by nuclear magnetic resonance analysis (NMR) measurement.

  In the present specification, “a repeating unit derived from styrene” is a structural unit derived from styrene contained in a polymer when styrene or a styrene derivative is polymerized, and may have a substituent. Examples of the styrene derivative include -methylstyrene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, and the like. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, an alkoxyalkyl group having 1 to 5 carbon atoms, an acetoxy group, and a carboxyl group.

  Preferable examples of commercially available polystyrene-based elastomers include TUFPRENE (registered trademark) A, TUFPRENE (registered trademark) 125, TUFPRENE (registered trademark) 126S, Sorprene (registered trademark) T, Asaprene (registered trademark) T-411. , Asaprene (registered trademark) T-432, Asaprene (registered trademark) T-437, Asaprene (registered trademark) T-438, Asaprene (registered trademark) T-439, Tuftec (registered trademark) H1272, Tuftec (registered trademark) P1500 Tuftec (registered trademark) H1043, Tuftec (registered trademark) H1052, Tuftec (registered trademark) H1062, Tuftec (registered trademark) M1943, Tuftec (registered trademark) P2000, Septon (registered trademark) 1001, Septon (registered trademark) 8004, Septon Trademark) 4033, Septon (R) S2104, and the like.

  The content of the thermoplastic resin (preferably elastomer) in the temporary adhesive composition used in the present invention is preferably 50.00 to 99.99% by mass with respect to the mass of the temporary adhesive composition excluding the solvent. 70.00 to 99.99 mass% is more preferable, and 88.00 to 99.99 mass% is particularly preferable. If content of a thermoplastic resin (preferably elastomer) is the said range, it will be excellent in adhesiveness and peelability.

  The elastomer in the temporary adhesive composition used in the present invention may be a combination of a plurality of types.

  Further, the temporary adhesive composition used in the present invention is a compound containing a fluorine atom and a thermoplastic resin (preferably an elastomer) in a mass ratio: a compound containing a fluorine atom: a thermoplastic resin (preferably an elastomer). = 0.001: 99.999 to 10: 90.00, preferably 0.001: 99.999 to 5: 95.00, and 0.010: 99.99 to 5: More preferably, it is 95.00.

The temporary adhesive composition of the present invention preferably contains a solvent. When the adhesive layer is formed by applying the temporary adhesive composition of the present invention, it is preferable to add a solvent. Any known solvent can be used without limitation, and an organic solvent is preferred. Preferable examples of the solvent include esters such as ethyl acetate, n-butyl acetate, isobutyl acetate and amyl formate, ethers such as diethylene glycol dimethyl ether, tetrahydrofuran and ethylene glycol monomethyl ether, and hydrocarbons such as mesitylene.
In addition to the above, as the organic solvent, the descriptions in paragraphs 0122 and 0123 of JP-A-2014-189731 can be referred to, and the contents thereof are incorporated in the present specification.

  When the temporary adhesive composition has a solvent, the content of the solvent of the temporary adhesive composition is preferably such that the total solid concentration of the temporary adhesive composition is 5 to 80% by mass from the viewpoint of applicability. 5 to 70 mass% is more preferable, and 10 to 60 mass% is particularly preferable.

  One type of solvent may be sufficient and two or more types may be sufficient. When there are two or more solvents, the total is preferably in the above range.

  The temporary adhesive composition used in the present invention may contain a compound containing a silicon atom in addition to the compound containing a fluorine atom or instead of the compound containing a fluorine atom. The compound containing a silicon atom is preferably liquid at 25 ° C.

  Further, the temporary adhesive composition used in the present invention may contain an antioxidant, a surfactant, a polymerizable compound, a solvent, and the like. The details of these can be referred to the description of JP-A-2014-189731, the contents of which are incorporated herein.

  Hereinafter, the present invention will be described more specifically with reference to examples. The raw material, the amount used, the ratio, the details of the process, the procedure of the process, and the like can be arbitrarily changed as long as the gist of the present invention is not exceeded. Therefore, the scope of the present invention is not limited by the following examples.

<Preparation of temporary adhesive composition>
The following compositions were mixed to obtain a uniform solution, followed by filtration using a polytetrafluoroethylene filter having a pore size of 5 μm to prepare compositions of Examples and Comparative Examples.

<< Composition of temporary adhesive composition >>
-Resins listed in Table 1: parts by mass listed in Table 1-Compounds containing fluorine atoms listed in Table 1: parts by mass listed in Table 1-Solvents listed in Table 1: parts by weight listed in Table 1 <Resin>
It shows in Table 2.
The 5% thermal mass decrease temperature of the resins P-1 to P-3, which is increased from 25 ° C. at 20 ° C./min, is 250 ° C. or higher.
<Compounds containing fluorine atoms>
Table 3 shows.
<Formation of laminate>
On a 12-inch silicon wafer (first wafer) having a plurality of rectangular semiconductor chips including bumps inside, a temporary bond composition described in Table 1 is used as a wafer bonder (XBS300, manufactured by SUSS MicroTec). While rotating at 50 rpm, 15 mL was dropped during 30 seconds. The rotation speed was increased to 800 rpm and held for 80 seconds. Then, the laminated body 1 by which the temporary adhesive layer was formed on the surface of the 1st wafer was obtained by heating at 110 degreeC for 3 minutes, and also heating at 190 degreeC for 3 minutes.
<Adhesion of laminate 1>
A 12-inch silicon wafer (second wafer) is applied to the surface of the laminate 1 on which the temporary adhesive layer is formed, at 190 ° C. under vacuum using a wafer bonder (XBS300, manufactured by SUSS MicroTech). The laminate 2 was obtained by pressure bonding for 3 minutes at a pressure of 11 MPa.
<Polishing of laminate 2>
The surface of the first wafer of the laminate 2 on which the temporary adhesive layer is not provided is thinned by polishing to 50 μm using a back grinder DFG8540 (manufactured by Disco Corporation) to obtain a laminate 3. .
<Heating test of laminate 3>
The laminate was heated on the hot plate for 60 minutes at the temperature shown in Table 1.
<Peeling after polishing>
The polished surface of the first wafer of the laminate 3 was faced down and fixed together with a dicing frame at the center of the dicing tape using a dicing tape mounter. After that, using a wafer debonder (XBC300 Gen2, manufactured by SUSS MicroTec), the second wafer is pulled up with a force of 50 mm / min in a direction perpendicular to the substrate surface of the first wafer at 25 ° C. And the laminated body 4 with which a temporary adhesive bond layer remains on the 1st wafer surface was obtained.

Evaluation <Measurement of abundance ratio of fluorine atoms>
The fluorine atom abundance ratio on the surface of the temporary adhesive layer was measured by X-ray photoelectron spectroscopy (ESCA).
After separating the second wafer from the laminated body 1, the abundance ratio of fluorine atoms on the surface of the temporary adhesive layer on the side where the second wafer is provided is set to an analysis area range of 1400 μm × 700 μm on the surface of the temporary adhesive film. On the other hand, a monochromatic AlKα ray was irradiated at 25 W and detected at a take-off angle of 45 °. The unit is expressed in%.
<Evaluation of peel strength>
The temporary adhesive layer remaining on the laminate 4 is pulled upward at 50 mm / min while maintaining the peeling angle (α) and peeling angle (β) shown in Table 1, and the force applied at that time is a force gauge ( The maximum value of force when measured using Imada Co., Ltd. (DS2-200N) was measured and evaluated according to the following criteria.
Here, the peeling angle (α) is a peeling angle of the temporary adhesive layer, which is an angle with respect to the substrate surface of the first wafer (an angle α in FIG. 1g). Further, the peeling angle (β) means a peeling angle with respect to one side of the rectangular shape of the first wafer surface (an angle β in FIG. 2).
A: 62.5N or more and 100 or less B: 10N or more and less than 62.5N, or more than 100N and less than 135N C: less than 10N or more than 135N <Evaluation of removability of copper oxide>
In the evaluation of the peeling force, the surface of the bump after peeling was observed using an optical microscope (manufactured by Olympus Corporation, product number: MX51, magnification: 100 times), and the removal of copper oxide was evaluated according to the following criteria. .
A: Copper oxide was removed, and metallic luster was confirmed on the bumps on the entire surface of the wafer.
B: Copper oxide was removed but not completely, and no metallic luster was observed on some bumps of the wafer.
C: Copper oxide was not removed, and no metallic luster was observed on the bumps on the entire surface of the wafer.
D: Copper oxide was not removed, and a temporary adhesive residue was also observed on a part of the wafer.
As is clear from the above results, it was found that the copper oxide can be removed by the peeling method of the present invention (Examples 1 to 18). Furthermore, it was peelable with an appropriate peeling force. On the other hand, when the heating temperature was 170 ° C. or less (Comparative Example 1), the copper oxide could not be removed. Moreover, when the temporary adhesive composition did not contain a compound containing a fluorine atom (Comparative Example 2) or when it did not contain a thermoplastic resin (Comparative Example 3), copper oxide could not be removed. In addition, there was a problem in peelability.

  Although the present invention has been described in detail with reference to the drawings and the foregoing specification, these drawings and specification are illustrative and representative and should not be limited. Aspects other than those disclosed can be understood and implemented by those skilled in the art upon studying the drawings, the disclosure, and the appended claims. In the claims, “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims (15)

A temporary adhesive composition including a thermoplastic resin and a compound containing a fluorine atom is applied on a carrier to form a temporary adhesive layer, and the surface on the temporary adhesive layer is opposite to the carrier. And forming a laminate by applying a wafer having copper as a main component and having at least one of a concave portion and a convex portion so that the side having at least one of the concave portion and the convex portion is in contact with the temporary adhesive layer, or
A temporary adhesive composition containing a compound containing a thermoplastic resin and a fluorine atom on the surface having at least one of the concave and convex portions of a wafer having copper as a main component and at least one of the concave and convex portions on the surface. To form a temporary adhesive layer, and apply a carrier on the temporary adhesive layer opposite to the surface in contact with the wafer to form a laminate,
A method for manufacturing a device substrate, comprising: heating the laminated body at a temperature exceeding 170 ° C., separating a carrier from the laminated body, and further peeling a temporary adhesive.   The method for manufacturing a device substrate according to claim 1, wherein the thermoplastic resin is an elastomer.   The method for producing a device substrate according to claim 2, wherein the elastomer has a 5% thermal mass reduction temperature of 250 ° C. or higher when the temperature is increased from 25 ° C. at 20 ° C./min.   The method for manufacturing a device substrate according to claim 2, wherein the elastomer includes a repeating unit derived from styrene.   The method for producing a device substrate according to any one of claims 2 to 4, wherein the elastomer is a block copolymer in which one end or both ends are styrene.   The device substrate manufacturing method according to claim 1, wherein the compound containing a fluorine atom further contains a lipophilic group.   The manufacturing method of the device substrate of any one of Claims 1-6 whose compound containing the said fluorine atom is a liquid state at 25 degreeC.   X-ray photoelectron spectroscopy on the surface of the temporary adhesive layer, measured by irradiating 25 W of monochromatic AlKα rays to the analysis area range of 1400 μm × 700 μm on the surface of the temporary adhesive layer and detecting at a take-off angle of 45 ° The abundance ratio of fluorine atoms using the method, wherein the abundance ratio of fluorine atoms on the surface of the temporary adhesive layer on the carrier side and the abundance ratio of fluorine atoms on the wafer side surface of the temporary adhesive layer The method for manufacturing a device substrate according to any one of claims 1 to 7, wherein one side is 10 to 35%.   The method for manufacturing a device substrate according to claim 1, wherein the temporary adhesive layer is in a liquid state at 25 ° C. and contains a compound containing silicon atoms.   The device substrate manufacturing method according to claim 1, wherein the carrier and the temporary adhesive layer are adjacent to each other.   The method for manufacturing a device substrate according to claim 1, wherein at least one of mechanical treatment and chemical treatment is performed on a wafer side surface of the laminate after heating the laminate.   The manufacturing method of the device substrate of any one of Claims 1-11 in which the temporary adhesive agent after the said peeling contains a copper oxide.   The method for manufacturing a device substrate according to claim 1, comprising peeling the temporary adhesive layer at an angle of 60 ° to 180 ° with respect to the substrate surface of the wafer.   The wafer has two or more rectangular semiconductor chips including at least one of a concave portion and a convex portion, and two opposite sides of the rectangular semiconductor chip are two opposite sides of another rectangular semiconductor chip. 14, and the temporary adhesive layer is peeled from an angle greater than 30 ° and less than 60 ° with respect to one side of the rectangular shape. The manufacturing method of the device board | substrate as described in 2.   The manufacturing method of a semiconductor device containing the manufacturing method of the device substrate of any one of Claims 1-14.