Method for manufacturing semiconductor device

Abstract

This method for manufacturing a semiconductor device comprises: a dicing step for dicing a resin film-coated semiconductor wafer having a semiconductor wafer and a resin film disposed on the semiconductor wafer; and a resin film removal step for removing the resin film from the resin film-coated semiconductor wafer after the dicing step. The resin film contains a photodissolvable resin. The resin film removal step includes: a photodissolution step for rendering the photodissolvable resin soluble by irradiating the resin film with light; a first cleaning step for supplying an aqueous solvent to the resin film while rotating the resin film-coated semiconductor wafer at a first rotation speed; and a second cleaning step for supplying the aqueous solvent to the resin film while rotating the resin film-coated semiconductor wafer at a second rotation speed higher than the first rotation speed.

Description

Manufacturing method for semiconductor devices

[0001] This disclosure relates to a method for manufacturing a semiconductor device.

[0002] Semiconductor devices are generally manufactured through the following process. First, a semiconductor wafer is attached to a dicing tape, and in this state, the semiconductor wafer is divided into individual semiconductor chips (dicing process). Next, processes such as a pickup process to pick up the semiconductor chips, and a semiconductor chip bonding process to bond the picked semiconductor chips to support members etc. using an adhesive (die bonding film) via heat and pressure are carried out to manufacture the semiconductor device.

[0003] In the dicing process, for example, a dicing blade is used to form grooves in a semiconductor wafer to separate it into semiconductor chips. At this time, water is sprayed onto the dicing blade and the processed area of ​​the semiconductor wafer to provide a cooling effect and to wash away foreign matter such as cutting dust. However, water containing foreign matter can remain on the semiconductor wafer, and this foreign matter may adhere to the surface of the semiconductor wafer after drying. Therefore, dicing apparatuses that have a separate cleaning means from the means of spraying water during cutting, and that remove foreign matter before drying the semiconductor wafer after dicing, are widely used (for example, Patent Document 1).

[0004] Japanese Patent Publication No. 2000-33346

[0005] However, even when using the conventional dicing apparatus described above, it is not easy to thoroughly clean the entire surface of the semiconductor wafer, and there are usually areas on the semiconductor wafer surface where foreign matter remains after cleaning. Therefore, in practice, after the semiconductor wafer is diced, semiconductor chips with foreign matter attached are removed, and only clean semiconductor chips are used in the manufacture of semiconductor devices, and there is still room for improvement in terms of semiconductor chip yield. It should be noted that, for example, the removal of foreign matter can be improved to some extent by extending the cleaning time using another cleaning method, but this method leads to an increase in the amount of cleaning solution used and a decrease in processing efficiency, and therefore does not provide a fundamental solution.

[0006] This disclosure aims to provide a method for manufacturing a semiconductor device that can efficiently and sufficiently remove foreign matter such as cutting dust generated during dicing from a semiconductor wafer.

[0007] The inventors have found that by using a resin film containing a photo-melting resin to capture foreign matter generated during dicing, and by removing the resin film after dicing using a specific method, the ability to remove foreign matter can be improved.

[0008] This disclosure includes the following aspects: [1] A method for manufacturing a semiconductor device, comprising: a dicing step of dicing a semiconductor wafer having a semiconductor wafer and a resin film disposed on the semiconductor wafer; a resin film removal step of removing the resin film from the resin film semiconductor wafer after the dicing step, wherein the resin film comprises a photomeltable resin, and the resin film removal step includes a photomelting step of irradiating the resin film with light to melt the photomeltable resin; a first cleaning step of supplying an aqueous solvent to the resin film while rotating the resin film semiconductor wafer at a first rotational speed; and a second cleaning step of supplying an aqueous solvent to the resin film while rotating the resin film semiconductor wafer at a second rotational speed faster than the first rotational speed. [2] The method for manufacturing a semiconductor device according to [1], wherein the second rotational speed is 2 times or more and less than 10 times the first rotational speed. [3] The method for manufacturing a semiconductor device according to [1] or [2], wherein the first rotation speed is 200 rpm or more and 1000 rpm or less. [4] The method for manufacturing a semiconductor device according to any one of [1] to [3], wherein the second rotation speed is 1000 rpm or more and 2000 rpm or less. [5] The method for manufacturing a semiconductor device according to any one of [1] to [4], wherein the photo-meltable resin comprises a reaction product of a polythiol compound having a disulfide bond and two or more thiol groups, and a compound having two or more functional groups that can react with thiol groups. [6] The method for manufacturing a semiconductor device according to any one of [1] to [5], wherein the photo-meltable resin comprises a reaction product of a polythiol compound having a disulfide bond and a hydroxyl group and two or more thiol groups, and a cyclic ether compound having a polyether group and two or more cyclic ether groups. [7] The method for manufacturing a semiconductor device according to any one of [1] to [6], wherein the elastic modulus of the photomeltable resin is 200,000 Pa or less.

[0009] According to one aspect of this disclosure, it is possible to provide a method for manufacturing a semiconductor device that can efficiently and sufficiently remove foreign matter such as cutting powder generated during dicing from a semiconductor wafer.

[0010] Figure 1 is a schematic cross-sectional view illustrating one embodiment of a semiconductor device manufacturing method. Figure 2 is a schematic perspective view showing the cleaning process in the semiconductor device manufacturing method.

[0011] The embodiments of this disclosure will be described in detail below, with reference to the drawings as necessary. However, this disclosure is not limited to the embodiments described below. In the embodiments described below, the components (including processes, etc.) are not essential unless otherwise specified. The same reference numerals are used for identical or equivalent parts, and redundant descriptions are omitted. Also, unless otherwise specified, positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. The dimensions of the components in each figure are conceptual, and the relative sizes of the components are not limited to those shown in each figure.

[0012] The same applies to numerical values ​​and their ranges in this disclosure, and this disclosure is not limited. Numerical ranges indicated using “~” in this specification include the numerical values ​​before and after “~” as the minimum and maximum values, respectively. In numerical ranges described in steps in this specification, the upper or lower limit of one numerical range may be replaced by the upper or lower limit of another numerical range described in steps. Also, in numerical ranges described in this specification, the upper or lower limit of that numerical range may be replaced by the values ​​shown in the examples.

[0013] In this specification, the term "layer" includes not only structures that are formed across the entire surface when observed in a plan view, but also structures that are formed in only a part of the surface. In this specification, the term "process" includes not only independent processes, but also processes that cannot be clearly distinguished from other processes, as long as their intended function is achieved.

[0014] In this specification, (meth)acrylate means acrylate or the corresponding methacrylate. The same applies to other similar expressions such as (meth)acrylic copolymer.

[0015] Unless otherwise specified, each component and material exemplified herein may be used alone or in combination of two or more.

[0016] [First Embodiment: Method for Manufacturing Semiconductor Device] An embodiment of the present disclosure is a method for manufacturing a semiconductor device, comprising: a step of dicing a semiconductor wafer and a semiconductor wafer with a resin film having a resin film disposed on the semiconductor wafer (dicing step); and a step of removing the resin film from the semiconductor wafer with the resin film after the dicing step (resin film removing step). In this manufacturing method, the resin film contains a photo-meltable resin. Further, the resin film removing step includes: a photo-melting step of irradiating the resin film with light to melt the photo-meltable resin; a first cleaning step of supplying an aqueous solvent to the resin film while rotating the semiconductor wafer with the resin film at a first rotation speed; and a second cleaning step of supplying the aqueous solvent to the resin film while rotating the semiconductor wafer with the resin film at a second rotation speed higher than the first rotation speed.

[0017] Hereinafter, each step of the present embodiment will be described with reference to FIG. 1 and FIG. 2.

[0018] <Dicing Step> In the dicing step, first, a semiconductor wafer with a resin film 7 including a semiconductor wafer 1 and a resin film 3 disposed on the semiconductor wafer 1 is prepared, and the semiconductor wafer with a resin film 7 is placed on a dicing tape 5 (see FIG. 1(a)).

[0019] Examples of the semiconductor wafer 1 include monocrystalline silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide. The semiconductor wafer 1 may have a circuit forming surface. The thickness of the semiconductor wafer 1 may be, for example, 10 to 1000 μm, 20 to 900 μm, or 30 to 800 μm.

[0020] The photo-meltable resin contained in the resin film 3 may be a resin having properties such as a decrease in elastic modulus and an increase in loss tangent (tan δ) when its molecular weight is reduced by irradiation with light. Further, the photo-meltable resin is a water-insoluble resin, and may be a resin that provides a water-soluble gel-like substance or liquid substance when its molecular weight is reduced by irradiation with light. Details of the photo-meltable resin will be described later.

[0021] The thickness of the resin film 3 may be, for example, 0.1 to 1000 μm, 1 to 500 μm, or 1 to 10 μm.

[0022] Examples of dicing tape 5 include plastic films such as polytetrafluoroethylene film, polyethylene terephthalate film, polyethylene film, polypropylene film, polymethylpentene film, and polyimide film. The dicing tape may also be subjected to surface treatments such as primer application, UV treatment, corona discharge treatment, polishing, and etching, as needed. The dicing tape may be adhesive. Such a dicing tape may be a plastic film to which adhesiveness has been imparted, or an adhesive layer may be provided on one side of the plastic film. The adhesive layer may consist of a UV-curing or UV-non-curing pressure-sensitive adhesive, and is not particularly limited as long as it has sufficient adhesive strength to prevent semiconductor elements from scattering during dicing; conventionally known adhesives can be used.

[0023] The thickness of the dicing tape 5 may be, for example, 10 to 1000 μm, 30 to 500 μm, or 50 to 300 μm.

[0024] Next, at least the semiconductor wafer 1 and the resin film 3 (and even a part of the dicing tape 5) are diced with a dicing blade 9 to separate them into individual pieces (see Figure 1(b)). Dicing with the dicing blade 9 can be performed using commercially available equipment. Dicing with the dicing blade 9 is performed, for example, on the semiconductor wafer 7 with the resin film in a cutting pattern that forms a grid in a plan view.

[0025] Dicing with the dicing blade 9 is usually performed while spraying cooling water (cutting water) onto the contact points between the semiconductor wafer 1 or resin film 3 and the dicing blade 9, in order to suppress the temperature rise at these contact points. The resin film 3 has the function of capturing cutting dust (debris) generated during dicing, and since the photomeltable resin contained in the resin film 3 is a water-insoluble resin, it is possible to sufficiently prevent the adhesion of cutting dust to the semiconductor wafer 1 during dicing while sufficiently suppressing the dissolution of the resin film by the cooling water. In addition, although cooling water containing cutting dust may remain on the resin film 3, the cutting dust is captured by the resin film 3 even when the semiconductor wafer 1 is dried after dicing, so it is possible to sufficiently prevent the cutting dust from adhering (fixing) to the semiconductor wafer 1. Furthermore, generally, it is not easy to completely remove the resin film, and there is a concern that the surface of the semiconductor wafer may be contaminated by residual resin, but in this embodiment, the resin film can be efficiently and sufficiently removed along with foreign matter by going through a resin film removal process that includes a photomelting process, a first cleaning process and a second cleaning process.

[0026] In this embodiment, a dicing blade 9 is used in the dicing process, but the dicing means may be laser dicing, plasma dicing, or the like. When the dicing means is laser dicing, foreign matter such as scattered material (debris) and molten material (dross) that is generated, and when the dicing means is plasma dicing, deposits that are generated, are captured by the resin film, thus effectively preventing them from adhering to the semiconductor wafer.

[0027] In this way, the semiconductor wafer 1 and the resin film 3 are each separated into individual pieces, and a semiconductor chip 7a with a resin film piece having a semiconductor chip 1a and a resin film piece 3a can be obtained. In this specification, the entire collection of multiple semiconductor chips with resin film pieces after separation may be referred to as a "resin film-coated semiconductor wafer".

[0028] The shape of the semiconductor chip 1a in plan view may be, for example, a square or a rectangle. The area of ​​the semiconductor chip 1a may be, for example, 1 to 250 mm². ２ , 4-200mm ２ , or 9-150 mm ２It may be as follows. The length of one side of the semiconductor chip 1a may be 1 mm or more, 2 mm or more, or 3 mm or more, and may be 20 mm or less, 18 mm or less, or 15 mm or less. The thickness of the semiconductor chip 1a may be the same as the thickness of the semiconductor wafer 1.

[0029] <Resin film piece removal step> In this step, first, as shown in Fig. 1(c), the resin film 3 of the semiconductor wafer 7 with a resin film is irradiated with light A to melt the photo-meltable resin contained in the resin film 3. Thereafter, as shown in Fig. 2, an aqueous solvent W is supplied to the resin film 3 (resin film piece 3a) while rotating the semiconductor wafer 7 with a resin film at a first rotation speed (first cleaning step), and then the aqueous solvent W is supplied to the resin film 3 (resin film piece 3a) while rotating the semiconductor wafer 7 with a resin film at a second rotation speed that is higher than the first rotation speed (second cleaning step).

[0030] (Photo-melting step) The photo-meltable resin contained in the resin film 3 (resin film piece 3a) is depolymerized upon irradiation with light A to form a gel or liquid. The light A irradiated to the resin film 3 (resin film piece 3a) may be, for example, ultraviolet light or visible light. The wavelength of light A can be appropriately selected depending on, for example, the type of photoradical generator used. The wavelength of light A may be, for example, 150 to 830 nm. Light A may include, for example, light with a wavelength of 405 nm or light with a wavelength of 365 nm.

[0031] The irradiation with light A can be performed, for example, using a light irradiation device under the condition that the irradiation amount is 1000 mJ / cm ２ or more. The irradiation amount can be appropriately set according to, for example, the wavelength of light A or the like. The irradiation amount is, for example, 3000 mJ / cm ２ or more, 5000 mJ / cm ２ or more, or 10000 mJ / cm ２ or more, and may be 100000 mJ / cm ２ or less, 80000 mJ / cm ２ or less, or 60000 mJ / cm ２ or less.

[0032] Irradiation dose refers to the product of illuminance and irradiation time (seconds). Examples of light sources for ultraviolet or visible light irradiation include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, and LED lamps.

[0033] (First and Second Cleaning Steps) The first and second cleaning steps can be performed, for example, using a spinner cleaning unit built into the dicing apparatus. In this case, as shown in Figure 2, while rotating the dicing tape 5 and the semiconductor wafer 7 with a resin film (semiconductor chip 7a with a resin film piece) placed on the dicing tape 5 in the direction of arrow B, an aqueous solvent W is sprayed from the tip of the nozzle 30 of the spinner cleaning unit toward the resin film 3, and the resin film 3 is removed together with foreign matter.

[0034] Examples of the aqueous solvent W include water, a mixed solvent of water and a hydrophilic organic solvent, etc. In the mixed solvent of water and a hydrophilic organic solvent, the proportion of water can be, for example, 80% by mass or more. The aqueous solvent W may also contain, for example, a pH adjusting agent.

[0035] The aqueous solvent W may be water. Examples of water include tap water, natural water, purified water, distilled water, ion-exchanged water, pure water, and ultrapure water (Milli-Q water, etc.). Milli-Q water refers to ultrapure water obtained using a Milli-Q water production system from Merck Millipore (Merck). Since the water has reduced impurities, it may be purified water, distilled water, ion-exchanged water, pure water, or ultrapure water.

[0036] Examples of hydrophilic organic solvents include alcohols such as methanol, ethanol, 2-propanol, and 1,2-propanediol; and glycol ethers such as ethylene glycol monomethyl ether, propylene glycol monomethyl ether, ethyl cellosolve, propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, butyl cellosolve, ethylene glycol monoisobutyl ether, propylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and dipropylene glycol monomethyl ether.

[0037] Examples of pH adjusters include inorganic acids, inorganic bases, organic acids, and organic bases. Examples of inorganic acids include nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid, and boric acid. Examples of inorganic bases include sodium hydroxide, potassium hydroxide, and calcium hydroxide. Examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, acrylic acid, benzoic acid, and picolinic acid. Examples of organic bases include primary amines, secondary amines, tertiary amines, tetramethylammonium hydroxide, tetraethylammonium hydroxide, and imidazole compounds.

[0038] The spraying of the water-based solvent W can be carried out, for example, by a two-fluid cleaning method. A two-fluid cleaning method refers to a cleaning method that uses a mixed cleaning fluid, which is created by mixing compressed gas (e.g., clean air) with a liquid to form a mist. In the two-fluid cleaning method, a higher cleaning capacity can be achieved by bombarding the target object with a minute amount of liquid (water-based solvent) at high speed. On the other hand, high-pressure cleaning water is not required, and the impact on the target object is reduced, thus suppressing the generation of new foreign matter due to damage to the target object.

[0039] When spraying the aqueous solvent W, the nozzle 30 may be moved back and forth along a line connecting the peripheral edge and the central part of the resin-coated semiconductor wafer 7. The reciprocating speed of the nozzle 30 is not particularly limited and may be, for example, 30 to 60 seconds, 15 to 30 seconds, or 1 to 15 seconds per reciprocating motion.

[0040] The first rotational speed in the first cleaning step is preferably 200 rpm or more, more preferably 300 rpm or more, and even more preferably 400 rpm. A first rotational speed of 200 rpm or more allows for more reliable removal of foreign matter and resin film. Alternatively, the first rotational speed is preferably 1000 rpm or less, more preferably 800 rpm or less, and even more preferably 600 rpm or less. A first rotational speed of 1000 rpm or less allows for stable execution of the first cleaning step.

[0041] The cleaning time in the first cleaning step is not particularly limited and may be, for example, 10 to 500 seconds, 20 to 200 seconds, or 30 to 100 seconds.

[0042] The second rotational speed in the second cleaning step is preferably 1000 rpm or higher. A second rotational speed of 1000 rpm or higher allows for more reliable removal of foreign matter and resin film. Alternatively, the second rotational speed is preferably 2000 rpm or lower, more preferably 1500 rpm or lower, and even more preferably 1200 rpm or lower. A second rotational speed of 2000 rpm or lower allows for stable execution of the second cleaning step.

[0043] Furthermore, it is preferable that the second rotational speed is at least twice the first rotational speed. By having the second rotational speed at least twice the first rotational speed, foreign matter and resin film can be removed more reliably. Furthermore, it is preferable that the second rotational speed is less than 10 times the first rotational speed, more preferably 5 times or less, and even more preferably 3 times or less. By having the second rotational speed at least 10 times the first rotational speed, the first and second cleaning processes can be carried out stably.

[0044] The cleaning time in the second cleaning step is not particularly limited and may be, for example, 10 to 500 seconds, 20 to 200 seconds, 30 to 100 seconds, or 30 to 90 seconds. The cleaning time in the first cleaning step may be 0.1 to 10 times, 1.5 to 5 times, or 2 to 4 times the cleaning time in the second cleaning step.

[0045] In the resin film removal process, the number of times the first cleaning process and the second cleaning process are combined may be once or two or more times. When the combination is performed two or more times, the first and second rotation speeds may be kept constant for all combinations, or the rotation speeds may be changed for each combination. Furthermore, the rotation direction of the resin film-coated semiconductor wafer 7 (resin film-coated semiconductor chip 7a) is not particularly limited, and may be, for example, in the opposite direction to arrow B. Moreover, when the combination of the first cleaning process and the second cleaning process is performed two or more times, for example, after rotating along arrow B and cleaning a predetermined number of times, the rotation direction may be switched to the opposite direction to arrow B.

[0046] <Photo-fused resin>

[0047] The photo-meltable resin used in this embodiment may be, for example, a reaction product of a compound (compound A) having a disulfide bond (-S-S-) and two or more thiol groups (-SH) and a compound (compound B) having two or more functional groups that can react with thiol groups. The resin film 3 may further contain a photoradical generator in addition to the photo-meltable resin.

[0048] The mechanism by which photo-soluble resins become low-molecular-weight (melt) is not entirely clear, but the following mechanisms are possible, however, not limited to these. Photo-soluble resins contain compounds having disulfide bonds (reaction products of compound A and compound B). When the photo-soluble resin contained in a resin film is irradiated with light, the disulfide bonds in the photo-soluble resin decompose (cleave) and thiyl radicals are generated. At this time, if a photoradical generator (intramolecular cleavage type photoradical generator) is present, the thiyl radicals react with the photoradical generator, and the thiyl radicals are capped by the photoradical generator. As a result, the compounds having disulfide bonds become low-molecular-weight, and the cured product is photosoftened (photomelted). Another possible mechanism involves photo-induced radicals generated by a photoradical generator (intramolecular cleavage-type photoradical generator) directly reacting with the disulfide bond, leading to the formation of a photo-induced radical-thioether bond and the generation of a thiyl radical. This thiyl radical then reacts with another photo-induced radical, causing the compound containing the disulfide bond to become lower in molecular weight, resulting in the softening of the photocured product. The reaction that cleaves the disulfide bond is considered an irreversible reaction.

[0049] The resin film 3 can be formed, for example, by forming a curable composition layer on a semiconductor wafer 1 using a curable composition containing compound A, compound B, a photoradical generator, and optionally a curing accelerator to promote the reaction between compound A and compound B, and then curing it by heating or light irradiation (reacting compound A and compound B). In this case, the resin film 3 can be said to contain the cured product of the curable composition. Furthermore, the cured product of the curable composition can be said to contain the reaction product of compound A and compound B and the photoradical generator. The curable composition may be a thermosetting composition that hardens by heating, or a photocurable composition that hardens by light irradiation, but in one embodiment it may be a thermosetting composition.

[0050] Compound A has one or more (two or more) disulfide bonds in its molecule. The number of disulfide bonds in compound A may be, for example, 1 to 1000, 1 to 500, or 1 to 100.

[0051] The upper limit of the number of thiol groups in compound A may be, for example, 10 or less, 8 or less, 6 or less, or 4 or less. Compound A may be, for example, a dithiol compound having two thiol groups. Compound A may be a high molecular weight component of a polymer or oligomer. A compound having two thiol groups (-SH) can be considered a compound consisting of two thiol groups and a group (first linking group) that contains a disulfide bond and links the two thiol groups.

[0052] The molecular weight or number-average molecular weight (Mn) of compound A may be, for example, 100 to 1,000,000, 200 to 3,000,000, 300 to 1,000,000, 400 to 10,000, or 500 to 5,000. In this specification, the number-average molecular weight (Mn) and the weight-average molecular weight (Mw), described later, are polystyrene-converted values ​​obtained using a calibration curve with standard polystyrene by gel permeation chromatography (GPC).

[0053] Compound A may be a compound (e.g., a polymer or oligomer) having linear or branched molecular chains and terminal groups, with disulfide bonds in the molecular chains. In this case, the terminal groups in compound A may be thiol groups. Including such a compound as compound A tends to further improve the photomeltable properties of the photomeltable resin (the reaction product of compound A and compound B). The molecular chains in compound A may contain disulfide bonds and polyether chains, or may consist of disulfide bonds and polyether chains.

[0054] Compound A is, for example, formula (1): HS-(X-S-S) ｎ１ The compound may be represented as -X-SH (compound A1). In the formula, X represents a polyether group (polyether chain). Multiple Xs may be the same or different from one another. n1 represents an integer of 1 or more. n1 may be, for example, 1 or more, or 4 or more, and may be 1000 or less. (A) If component is compound A1, then -(X-S-S) ｎ１ The group represented by -X- is the first linking group. The compound obtained by chain extension of compound A1 may be, for example, a Michael adduct of compound A1 or a thiourethane derivative of compound A1.

[0055] The polyether group X may be, for example, a polyoxyalkylene group (polyoxyalkylene chain). The polyether group X may be, for example, -X １ -O-X ２ -O-X ３ It may be a base represented by -. １ ~X ３ Each of these may independently be an alkylene group, and may be an alkylene group having 1 to 2 carbon atoms (e.g., a methylene group, an ethylene group). The polyether chain X may be, for example, -CH ２ CH ２ -O-CH ２ -O-CH ２ CH ２ - are some examples.

[0056] Examples of commercially available compounds A1 include the Thiocol LP series (dithiol with a disulfide bond, manufactured by Toray Fine Chemicals Co., Ltd.). Compound A can also be obtained by converting the reactive functional group (e.g., carboxyl group, hydroxyl group) and disulfide bond at the terminal of a compound to a thiol group. Examples of compounds with a reactive functional group and a disulfide bond at the terminal include 3,3'-dithiodipropionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), dithiodiethanol, and cystamine.

[0057] When compound A1 is used as compound A, the content of compound A1 may be 15% by mass or more, 25% by mass or more, or 35% by mass or more, and may be 80% by mass or less, 70% by mass or less, or 60% by mass or less, based on the total amount of the curable composition (solid content excluding solvent).

[0058] Furthermore, compound A may be a polythiol compound (compound A2) having a disulfide bond (-S-S-) and a hydroxyl group (-OH) in its molecule, and two or more thiol groups (-SH). Compound A2 may be, for example, a dithiol compound having two thiol groups (-SH). Compound A2 may be a high molecular weight component of a polymer or oligomer. The compound having two thiol groups (-SH) may be a compound consisting of two thiol groups and a group (first linking group) that includes a disulfide bond and a hydroxyl group and links the two thiol groups.

[0059] Compound A2 has one or more (two or more) disulfide bonds in its molecule. The number of disulfide bonds in component (A) may be, for example, 1 to 100 or 2 to 50.

[0060] Compound A2 has one or more (two or more) hydroxyl groups in its molecule. The number of hydroxyl groups in component (A) may be, for example, 1 to 100 or 2 to 50.

[0061] Compound A2 may be, for example, a compound having a disulfide bond and a structure represented by the following formula (2), and having two or more thiol groups.

[0062]

[0063] In equation (2), * indicates a coupling.

[0064] A compound having a disulfide bond and the structure represented by formula (2), and having two or more thiol groups, can be obtained, for example, by a method comprising the step of reacting a compound represented by formula (2-1) with a compound represented by formula (2-2). That is, a compound having a disulfide bond and the structure represented by formula (2), and having two or more thiol groups, may be, for example, a reaction product (polymer) of a compound represented by formula (2-1) with a compound represented by formula (2-2).

[0065]

[0066] In formula (2-1), X ４ X represents a polyether group. There are multiple X groups. ４ These may be the same as or different from each other. An example of a polyether group represented by X4 is the same as X in formula (1).

[0067] n2 may be, for example, 1 or more, 2 or more, 3 or more, or 4 or more, and may be 1000 or less, 500 or less, 200 or less, or 100 or less.

[0068] Examples of commercially available compounds represented by formula (2-1) include the Thiocol LP series (dithiol having a disulfide bond, manufactured by Toray Fine Chemicals Co., Ltd.).

[0069] In formula (2-2), X ５ X represents a polyether group. There are multiple X groups. ５ They may be the same or different from each other. ５ The polyether group represented by may be, for example, a polyoxyalkylene group. ２ The polyether group represented by -X ５Ａ - [O-X ５Ｂ ] ｎ３ It may be a base represented by -. ５Ａ and X ５ＢEach of these may independently be an alkylene group, and may be an alkylene group having 1 to 3 carbon atoms (for example, a methylene group, an ethylene group, or a propylene group). ５Ｂ n3 may be the same or different from each other. n3 represents an integer greater than or equal to 1. n3 may be, for example, 1 or greater, 2 or greater, 3 or greater, or 4 or greater, and may be 1000 or less, 500 or less, 200 or less, 100 or less, or 50 or less.

[0070] The molecular weight or number-average molecular weight (Mn) of the compound represented by formula (2-2) may be, for example, 100 to 10000, 150 to 5000, or 200 to 2000.

[0071] The epoxy equivalent of the compound represented by formula (2-2) may be 50 to 2000 g / eq, 80 to 1500 g / eq, or 100 to 1000 g / eq.

[0072] Examples of commercially available compounds represented by formula (2-2) include the Denacol EX series (EX-850, EX-851, EX-821, EX-830, EX-832, EX-841, EX-861, EX-920, manufactured by Nagase ChemteX Corporation).

[0073] The reaction product (polymer) of the compound represented by formula (2-1) and the compound represented by formula (2-2) may be, for example, the compound represented by the following formula (2-3).

[0074]

[0075] In formula (2-3), X ４ , X ５ , and n2 are synonymous with the above. Multiple X ４ , X ５ n2 and n4 may be the same or different from each other. n4 represents an integer greater than or equal to 1.

[0076] n4 may be, for example, 1 or more, 2 or more, 3 or more, or 4 or more, and may be 1000 or less, 500 or less, 200 or less, or 100 or less.

[0077] The reaction (polymerization) between the compound represented by formula (2-1) and the compound represented by formula (2-2) can be carried out by appropriately combining conventional dispersants such as stirrers, swivels, three-roll mills, ball mills, and bead mills.

[0078] The heating temperature for the reaction (polymerization) between the compound represented by formula (2-1) and the compound represented by formula (2-2) may be, for example, 0 to 200°C, 30 to 150°C, or 60 to 100°C. The heating time for the reaction (polymerization) between the compound represented by formula (2-1) and the compound represented by formula (2-2) may be, for example, 0.1 to 168 hours, 72 hours or less, 24 hours or less, 12 hours or less, 6 hours or less, 4 hours or less, 3 hours or less, or 2 hours or less.

[0079] In the reaction (polymerization) between the compound represented by formula (2-1) and the compound represented by formula (2-2), the thiol equivalent of the compound represented by formula (2-1) and the epoxy equivalent of the compound represented by formula (2-2) are adjusted so that the resulting reaction product has two or more thiol groups.

[0080] The reaction (polymerization) between the compound represented by formula (2-1) and the compound represented by formula (2-2) may be carried out in the presence of a curing accelerator (catalytic curing agent) as needed. Examples of curing accelerators (catalytic curing agents) include those similar to those used in the curable compositions described later.

[0081] The content of the curing accelerator may be 100 ppm by mass or more, 300 ppm by mass or more, or 500 ppm by mass or more, and may be 10,000 ppm by mass or less, 8,000 ppm by mass or less, or 5,000 ppm by mass or less, based on the total amount of the compound represented by formula (2-1) and the compound represented by formula (2-2).

[0082] The weight-average molecular weight (Mw) of compound A2 may be, for example, 2000 or more, 2500 or more, 3000 or more, or 3500 or more, from the viewpoint of film-forming properties of the curable composition layer. The upper limit of the Mw of compound A2 may be, for example, 15000 or less or 10000 or less.

[0083] When compound A2 is used as compound A, the content of compound A may be 40% by mass or more, 50% by mass or more, or 60% by mass or more, and may be 90% by mass or less, 85% by mass or less, or 80% by mass or less, based on the total amount of the curable composition (solids excluding the solvent).

[0084] Compound B is a compound having two or more functional groups that can react with a thiol group. Examples of functional groups that can react with a thiol group include cyclic ether groups (oxirane group (oxiranyl group, epoxy group), oxetane group (oxetanyl group), tetrahydrofuryl group, tetrahydropyranyl group, etc.); isocyanate groups; and ethylenically unsaturated groups (C=C). The upper limit of the number of functional groups in compound B may be, for example, 10 or less, 8 or less, 6 or less, or 4 or less.

[0085] In one embodiment, compound B may be compound B1 having a polyether group (polyether chain) and two or more cyclic ether groups. By using compound B1 as compound B, the low molecular weight components generated by irradiating the photo-soluble resin with light tend to have many polyether chains or hydroxyl groups and exhibit water solubility, making it possible to remove the low molecular weight components with an aqueous solvent.

[0086] The cyclic ether group may be an oxirane group, from the viewpoint of reactivity and availability. That is, compound B1 is an oxirane compound (epoxy compound) having a polyether chain and two or more oxirane groups (oxiranyl groups, epoxy groups). In this specification, the cyclic ether group includes groups having a cyclic ether structure (a structure containing a cyclic ether group). For example, the oxirane group includes groups having an oxirane structure (a structure containing an oxirane group (oxiranyl group, epoxy group)), such as a glycidyl group, a glycidyl ether group, and an epoxycyclohexyl group.

[0087] The molecular weight or number-average molecular weight of compound B1 may be, for example, 100 to 1,000,000, 100 to 500,000, 100 to 10,000, 150 to 5,000, or 200 to 2,000.

[0088] If the cyclic ether group of compound B1 is an oxirane group (oxiranyl group, epoxy group), the epoxy equivalent of compound B1 may be 50 to 2000 g / eq, 80 to 1500 g / eq, or 100 to 1000 g / eq.

[0089] Compound B1 may be compound B1a having two cyclic ether groups, or compound B1b having three or more cyclic ether groups. Compound B1a may be a compound (e.g., a polymer or oligomer) having a linear molecular chain and terminal groups, with a polyether chain in the molecular chain. In this case, the terminal groups in compound B1a may be cyclic ether groups. Compound B1a can be considered as a compound comprising two cyclic ether groups and a polyether chain, with a group (second linking group) linking the two cyclic ether groups. Compound B1b may be a compound in compound B1a having one or more cyclic ether groups as a side chain or substituent of the second linking group. Compound B1 may contain both compound B1a and compound B1b, as this can further shorten the curing time and further improve photomeltable and water-soluble properties.

[0090] Compound B1a may be a compound (e.g., a polymer or oligomer) having a linear molecular chain and terminal groups, with a polyether chain in the molecular chain. In this case, the terminal group in compound B1a may be a cyclic ether group. When compound B is compound B1a, low molecular weight components generated by irradiating the photo-soluble resin with light tend to be easily removed with an aqueous solvent. The polyether chain as a molecular chain may have substituents such as a hydroxyl group or an alkyl group which may have a hydroxyl group. The molecular chain in compound B1a may contain a polyether chain, or may consist of a polyether chain.

[0091] Compound B1a is, for example, formula (3): Z-(Y) ｎ５The compound may be represented by -Z. In the formula, Y represents a polyether group (polyether chain), and Z represents a cyclic ether group. Multiple Zs may be the same or different from one another. n5 represents an integer of 1 or more. n5 may be, for example, 1 or more, or 2 or more, and may be 1000 or less. If compound B1a is a compound represented by formula (3), then -(Y) ｎ５ The group represented by - is the second linking group.

[0092] The polyether group Y may be, for example, a polyoxyalkylene group (polyoxyalkylene chain). The polyether group Y may be, for example, -Y １ -O-Y ２ -O-Y ３ It may be a base represented by -. Y １ ~Y ３ Each of these may independently be an alkylene group, and may be an alkylene group having 1 to 3 carbon atoms (e.g., a methylene group, an ethylene group, or a propylene group). As for the polyether chain Y, for example, -CH ２ CH ２ -O-CH ２ -CH ２ -O-CH ２ CH ２ - are some examples.

[0093] Examples of commercially available compounds B1a include the Denacol EX series (EX-850, EX-851, EX-821, EX-830, EX-832, EX-841, EX-861, EX-920, manufactured by Nagase ChemteX Corporation).

[0094] Compound B1b may be a compound having one or more cyclic ether groups as side chains to the second linking group (a polyether group as Y) in compound B1a.

[0095] Examples of commercially available compounds B1b include the Denacol EX series (EX-614B, EX-313, EX-512, EX-521, manufactured by Nagase ChemteX Corporation).

[0096] The mass ratio of the content of compound B1b to the total content of compound B1a and compound B1b (the mass of compound B1b / the total mass of compound B1a and compound B1b) may be between 0.01 and 0.40. When the mass ratio is 0.01 or higher, the curing time of the curable composition tends to be shortened, and when the mass ratio is 0.40 or lower, the photomeltable properties and water solubility tend to be improved. The mass ratio may also be 0.02 or higher or 0.03 or higher, and may be 0.35 or lower, 0.30 or lower, 0.25 or lower, 0.20 or lower, 0.15 or lower, or 0.10 or lower.

[0097] The content of compound B may be 10% by mass or more, 20% by mass or more, or 30% by mass or more, and may be 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the total amount of the curable composition (solid content excluding solvent).

[0098] The ratio of the total number of moles of thiol groups in compound A to the total number of moles of functional groups in compound B may be, for example, 0.90 or more, or 0.95 or more, and may be 1.10 or less, or 1.05 or less.

[0099] A photoradical generator is a component that generates radicals upon light irradiation. For example, a component used as a photopolymerization initiator can be used as a photoradical generator. Examples of photoradical generators include hydrogen abstraction type radical polymerization initiators, which generate radicals by abstracting hydrogen from other molecules upon light irradiation, and intramolecular cleavage type photoradical polymerization initiators, which generate two radicals through photocleavage upon light irradiation. Since the (photomelting) reaction proceeds easily, the photoradical generator may be an intramolecular cleavage type photoradical polymerization initiator.

[0100] Examples of hydrogen abstraction type photoradical generators include hexaarylbisimidazole (HABI) compounds, benzophenone compounds, thioxanthone compounds, fluorenone compounds, and α-diketone compounds.

[0101] Examples of HABI compounds include 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole (e.g., 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole), 2,2'-bis(o-bromophenyl)-4,4',5,5'-tetraphenylbiimidazole, and 2,2'-bis(o,p-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole. Examples include zole, 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetra(m-methoxyphenyl)biimidazole, 2,2'-bis(o,o'-dichlorophenyl)-4,4',5,5'-tetraphenylbiimidazole, 2,2'-bis(o-nitrophenyl)-4,4',5,5'-tetraphenylbiimidazole, and 2,2'-bis(o-methylphenyl)-4,4',5,5'-tetraphenylbiimidazole.

[0102] Examples of benzophenone compounds include 4,4'-bis(dimethylamino)benzophenone and 4,4'-bis(diethylamino)benzophenone.

[0103] Thioxanthone compounds include thioxanthone, 2-isopropylthioxanthone, 2-dodecylthioxanthone, 2-cyclohexylthioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, 1-phenoxythioxanthone, 1-methoxycarbonylthioxanthone, 2-ethoxycarbonylthioxanthone, 3-(2-methoxyethoxycarbonyl)-thioxanthone, 4-butoxycarbonylthioxanthone, 3-butoxycarbonyl-7-methylthioxanthone, 3,4-di-[2-(2-methoxyethoxy)-ethoxycarbonyl]-thioxanthone, 2-chlorothioxanthone, and 1-ethoxycarbonyl Examples include -3-ethoxythioxanthone, 1-ethoxycarbonyl-3-chlorothioxanthone, 1-chloro-4-n-propoxythioxanthone, 2-methyl-6-dimethoxymethyl-thioxanthone, 2-methyl-6-(1,1-dimethoxybenzyl)-thioxanthone, 6-ethoxycarbonyl-2-methoxy-thioxanthone, 6-ethoxycarbonyl-2-methylthioxanthone, 1-ethoxycarbonyl-3-(1-methyl-1-morpholinoethyl)-thioxanthone, 2-morpholinomethylthioxanthone, 2-methyl-6-morpholinomethylthioxanthone, and thioxanthone-2-carboxylic acid polyethylene glycol ester.

[0104] Examples of fluorenone compounds include 9-fluorenone, 3,4-benzo-9-fluorenone, 2-dimethylamino-9-fluorenone, 2-methoxy-9-fluorenone, 2-chloro-9-fluorenone, 2,7-dichloro-9-fluorenone, 2-bromo-9-fluorenone, 2,7-dibromo-9-fluorenone, 2-nitro-9-fluorenone, and 2-acetoxy-9-fluorenone.

[0105] Examples of α-diketone compounds include benzyl (also known as diphenylethanedione or dibenzoyl).

[0106] Examples of intramolecular cleavage-type photoradical generators include benzyl ketal-based photoradical generators, α-aminoalkylphenone-based photoradical generators, α-hydroxyalkylphenone-based photoradical generators, α-hydroxyacetophenone-based photoradical generators, and acylphosphine oxide-based photoradical generators.

[0107] Examples of benzyl ketal-based photoradical generators include 2,2-dimethoxy-1,2-diphenylethane-1-one (Omnirad 651).

[0108] Examples of α-aminoalkylphenone-based photoradical generators include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 (Omnirad 369), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (Omnirad 907), and 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (Omnirad 379EG).

[0109] Examples of α-hydroxyalkylphenone-based photoradical generators include 1-hydroxycyclohexylphenyl ketone (Omnirad 184).

[0110] Examples of α-hydroxyacetophenone-based photoradical generators include 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one (Omnirad 127) and 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Omnirad 1173).

[0111] Examples of acylphosphine oxide-based photoradical generators include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (OmniradTPO₄H) and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (Omnirad819).

[0112] The amount of photoradical generator may be 1% by mass or more, 3% by mass or more, 5% by mass or more, or 10% by mass or more, based on the total amount of the curable composition (solids excluding the solvent), and may be 30% by mass or less, 25% by mass or less, 20% by mass or less, or 15% by mass or less.

[0113] The ratio of the number of moles of the photoradical generator to the number of moles of compound A (moles of photoradical generator / moles of compound A) may be 0.1 or higher, 0.2 or higher, or 0.3 or higher, as this further improves the photosoftening properties.

[0114] The curing accelerator is a component that promotes the reaction between compound A and compound B, and includes a component that functions as a catalyst for the curing reaction (catalytic curing agent). Examples of curing accelerators include amine compounds, imidazole derivatives, quaternary ammonium salts, organometallic salts, and phosphorus compounds.

[0115] Examples of amine compounds include dicyandiamide, trimethylamine, triethylamine, tripropylamine, tributylamine, tri-n-octylamine, dimethylethylamine, dimethylpropylamine, dimethylbutylamine, dimethyl-n-octylamine, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]undeca-7-ene, benzyldimethylamine, 4-methyl-N,N-dimethylbenzylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 4-dimethylaminopyridine.

[0116] Examples of imidazole derivatives include 1-(1-cyanomethyl)-2-ethyl-4-methyl-1H-imidazole, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4,5-triphenylimidazole, 1-benzyl-2-imidazole, 1,2-dimethylimidazole, and 1-benzyl-2-phenylimidazole.

[0117] Examples of quaternary ammonium salts include tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyltributylammonium chloride, tetramethylammonium bromide, tetraethylammonium bromide, tetrabutylammonium bromide, benzyltrimethylammonium bromide, benzyltriethylammonium bromide, tetramethylammonium iodide, tetraethylammonium iodide, tetrabutylammonium iodide, and benzyltributylammonium iodide.

[0118] Examples of organometallic salts include bis(2,4-pentanedionato)zinc(II), zinc octoate, zinc naphthenate, cobalt naphthenate, copper naphthenate, iron acetylacetone, nickel octoate, and manganese octoate.

[0119] Examples of phosphorus compounds include tetraphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, triphenylphosphine, tri-p-tolylphosphine, tris(4-chlorophenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(2,6-dimethoxyphenyl)phosphine, triphenylphosphinetriphenylborane, tetraphenylphosphonium dicyanamide, and tetraphenylphosphonium tetra(4-methylphenyl)borate.

[0120] The content of the curing accelerator may be 0.01% by mass or more, 0.1% by mass or more, or 0.5% by mass or more, and may be 10% by mass or less, 5% by mass or less, or 2% by mass or less, based on the total amount of the curable composition (solid content excluding solvent).

[0121] The curable composition may further contain components that do not fall under Compound A, Compound B, the photoradical generator, and the curing accelerator (other components). Examples of other components include plasticizers; tackifiers such as tackifiers; antioxidants; leuco dyes; sensitizers; coupling agents and other adhesion enhancers; polymerization inhibitors; light stabilizers; defoamers; fillers; chain transfer agents; thixotropy agents; flame retardants; mold release agents; surfactants; lubricants; and antistatic agents. Known additives may be used. If the curable composition contains other components, the total amount of other components may be 0 to 95% by mass, 0.01 to 50% by mass, or 0.1 to 10% by mass, based on the total amount of the curable composition.

[0122] The curable composition may also be used as a varnish of the curable composition diluted with a solvent. Examples of solvents include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p-cymene; aliphatic hydrocarbons such as hexane and heptane; cyclic alkanes such as methylcyclohexane; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; carbonate esters such as ethylene carbonate and propylene carbonate; and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone (NMP). The solid content in the varnish, that is, the content of substances other than solvents in the varnish, may be 10 to 95% by mass, 15 to 95% by mass, 15 to 80% by mass, 15 to 70% by mass, 20 to 60% by mass, or 20 to 50% by mass, based on the total amount of varnish.

[0123] The curable composition can be prepared, for example, by a method that includes a step of mixing or kneading each of the above components. Mixing and kneading can be carried out by appropriately combining conventional dispersants such as stirrers, sieves, three-roll mills, ball mills, and bead mills.

[0124] The method for forming a curable composition layer on a semiconductor wafer 1 is not particularly limited, but examples include applying the curable composition onto the semiconductor wafer 1 using a spin coater, a bar coater, etc., or forming the curable composition into a film and attaching (transferring) the formed curable composition film to the semiconductor wafer 1. The curable composition film may be in a semi-cured state (B-stage state) before bonding the curable composition film to the semiconductor wafer 1. The curable composition layer may be arranged, for example, on the circuit formation surface of the semiconductor wafer 1.

[0125] The resin film 3 containing the photo-fused resin can be formed, for example, by heating the curable resin layer. Heating the curable composition layer causes the reaction between compound A and compound B to proceed, and a curing accelerator can accelerate this reaction. The reaction product of compound A and compound B (photo-fused resin) may be, for example, a compound (polymer) containing the structure represented by the following formula (4). On the other hand, the photoradical generator has little involvement in this reaction, and the cured product of the curable composition may contain the reaction product of compound A and compound B (photo-fused resin) and the photoradical generator.

[0126]

[0127] In equation (4), X represents the first linking group, and Y represents the second linking group. m represents an integer of 1 or more. m may be, for example, 50 or more, 100 or more, 500 or more, or 1000 or more. * represents a bond.

[0128] The heating temperature of the curable composition layer may be, for example, 0 to 200°C, 30 to 150°C, or 60 to 100°C. The heating time of the curable composition layer may be, for example, 0.1 to 168 hours, 72 hours or less, 48 ​​hours or less, 24 hours or less, 12 hours or less, 6 hours or less, 4 hours or less, 3 hours or less, or 2 hours or less.

[0129] The resin film 3 may be in a (fully) cured state (C-stage state). The thickness of the resin film 3 may be, for example, 10 to 1000 μm, 30 to 500 μm, or 50 to 200 μm.

[0130] The elastic modulus of the photo-soluble resin contained in the resin film 3 may be 200,000 Pa or less, 150,000 Pa or less, or 120,000 Pa or less, from the viewpoint of ease of cleaning in the resin film removal process. Furthermore, the elastic modulus of the photo-soluble resin may be 60,000 Pa or more, 70,000 Pa or more, or 75,000 Pa or more, from the viewpoint of physical strength in the dicing process. In this specification, the elastic modulus refers to the storage modulus determined by the sinusoidal vibration strain of a rheometer. The storage modulus can be measured using a rheometer at a frequency of 1 Hz for a test specimen with a diameter of 8 mm and a thickness of 100 μm.

[0131] As described above, according to this embodiment, multiple semiconductor chips 1a can be obtained from a semiconductor wafer 1 with sufficient suppression of foreign matter such as cutting dust (debris) adhering to them (see Figure 2(d)). The semiconductor device manufacturing method of this embodiment is useful in terms of reducing the amount of cleaning solution used, improving processing efficiency (shortening cleaning time, etc.), and improving the yield of clean semiconductor chips obtained from a unit amount of semiconductor wafer.

[0132] The semiconductor device manufacturing method of this embodiment may further include a step of polishing the back surface of the semiconductor wafer 1 before the dicing process (back grinding step), a step of irradiating the adhesive layer of the dicing tape 5 with ultraviolet light (ultraviolet irradiation step, if the dicing tape 5 is an ultraviolet curing type), a step of picking up the semiconductor chip 1a from the dicing tape 5 (pickup step), a step of heat-pressing and bonding the picked-up semiconductor chip 1a and the support member 13 via an adhesive layer 15 (die bonding film, etc.) (semiconductor chip bonding step), and a step of heat-curing the adhesive layer 15 (thermocuring step).

[0133] <Back Grinding Process> In the back grinding process, the back surface of the semiconductor wafer 1 (the surface opposite to the circuit formation surface) is ground. Back grinding of the semiconductor wafer 1 can be performed using a general back grinder.

[0134] The semiconductor wafer 1 subjected to the backgrinding process may be in the form of a laminate in which a substrate such as backgrinding tape is attached to the circuit formation surface of the semiconductor wafer 1, or it may be in the form of a laminate comprising the semiconductor wafer 1, resin film 3 and substrate in that order.

[0135] Examples of substrates include polyolefin films such as polyethylene (PE) and polypropylene (PP); polyester films such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate; polyvinyl chloride (PVC) films; polyimide (PI) films; polyphenylene sulfide (PPS) films; ethylene vinyl acetate (EVA) films; and polytetrafluoroethylene (PTFE) films. The substrate may also be a laminate comprising a substrate layer and an adhesive layer. In this case, the adhesive layer may consist of a UV-curable or UV-non-curable pressure-sensitive adhesive. From the viewpoint of avoiding the phenomenon of the photomeltable resin contained in the resin film 3 melting before the dicing process, it is preferable that the adhesive layer consists of a UV-non-curable pressure-sensitive adhesive (one that does not require light irradiation when removing the substrate). The thickness of the substrate may be, for example, 10 to 1000 μm, 30 to 500 μm, or 50 to 200 μm.

[0136] The thickness of the semiconductor wafer 1 after back-grinding is thinner than the thickness of the semiconductor wafer 1 before back-grinding, and may be, for example, 10 to 1000 μm, 20 to 900 μm, or 30 to 800 μm.

[0137] When a laminate formed by attaching a substrate such as backgrind tape to the circuit formation surface of a semiconductor wafer 1 is subjected to a backgrinding process, after the substrate is removed following the backgrinding process, a resin film 3 is placed on the surface of the semiconductor wafer 1 opposite to the back-ground surface (circuit formation surface) to obtain a semiconductor wafer 7 with a resin film. This semiconductor wafer 7 with a resin film is then subjected to a dicing process.

[0138] When a laminate comprising a semiconductor wafer 1, a resin film 3, and a substrate in this order is subjected to a backgrinding process, the substrate is removed after the backgrinding process to obtain a semiconductor wafer 7 with a resin film, in which the resin film 3 is placed on the side of the semiconductor wafer 1 opposite to the back-ground surface (circuit formation surface). This semiconductor wafer with a resin film is then subjected to a dicing process.

[0139] <Ultraviolet Irradiation Step> When the adhesive layer of the dicing tape 5 is composed of an ultraviolet-curing pressure-sensitive adhesive, the method for manufacturing the semiconductor device may include an ultraviolet irradiation step. In this step, ultraviolet light is irradiated onto the adhesive layer. In ultraviolet irradiation, the wavelength of the ultraviolet light may be 200 to 400 nm. The ultraviolet irradiation conditions are illuminance and irradiation dose of 30 to 240 mW / cm², respectively. ２ The range and 50-500 mJ / cm ２ It may be within that range.

[0140] <Pickup Process> In this process, the individual semiconductor chips 1a are separated from each other, and the semiconductor chips 1a that have been pushed up from the dicing tape 5 by a needle are picked up from the dicing tape 5 by a suction collet.

[0141] The ultraviolet irradiation step and the pickup step may be performed after the resin film fragment removal step, or before the resin film fragment removal step.

[0142] <Semiconductor Chip Bonding Process> In this process, the picked-up semiconductor chip 1a and the support member 13 are bonded together by heat and pressure through an adhesive layer 15 (die bonding film, etc.). The die bonding film can be any die bonding film used in this field. Multiple semiconductor chips 1a may be bonded to the support member 13.

[0143] The heating temperature in the heat-sealing process may be, for example, 80 to 160°C. The load in the heat-sealing process may be, for example, 5 to 15 N. The heating time in the heat-sealing process may be, for example, 0.5 to 20 seconds.

[0144] <Thermosetting Process> In this process, the adhesive layer 15 is thermoset. The heating temperature can be appropriately changed depending on the components of the die bonding film. For example, the heating temperature may be 60 to 200°C, 90 to 190°C, or 120 to 180°C. The heating time may be 30 minutes to 5 hours, 1 to 3 hours, or 2 to 3 hours. The temperature or pressure may be changed in stages.

[0145] In this way, a semiconductor device 20 (see Figure 1(e)) can be manufactured, comprising a semiconductor chip 1a, a support member 13 on which the semiconductor chip 1a is mounted, and an adhesive layer 15 provided between the semiconductor chip 1a and the support member 13 to bond the semiconductor chip 1a and the support member 13.

[0146] [Second Embodiment: Method for Manufacturing a Semiconductor Device with a Half-Cut Dicing Process] In the dicing process of the first embodiment described above, as shown in Figure 2(b), a method was applied in which a cut was made from the resin film 3 to the interface between the semiconductor wafer 1 and the dicing tape 5, thereby completely cutting the semiconductor wafer 1 (full-cut method). However, in the dicing process, a cut may be made in the semiconductor wafer with the resin film such that the cut does not reach the interface between the semiconductor wafer and the dicing tape (i.e., the depth of the cut is less than the sum of the thicknesses of the semiconductor wafer and the resin film) (half-cut method).

[0147] In other words, another embodiment of the present disclosure relates to a method for manufacturing a semiconductor device comprising a half-cut dicing process. The method for manufacturing a semiconductor device according to this embodiment comprises a step of dicing a semiconductor wafer having a semiconductor wafer and a resin film disposed on the semiconductor wafer (dicing step), a step of removing the resin film from the semiconductor wafer with the resin film after the dicing step (resin film removal step), and a step of back grinding the semiconductor wafer after the resin film removal step (back grinding step). In this manufacturing method, the resin film includes a photo-meltable resin. The resin film removal step also includes a photo-melt step of irradiating the resin film with light to melt the photo-meltable resin, a first cleaning step of supplying an aqueous solvent to the resin film while rotating the semiconductor wafer with the resin film at a first rotational speed, and a second cleaning step of supplying an aqueous solvent to the resin film while rotating the semiconductor wafer with the resin film at a second rotational speed faster than the first rotational speed.

[0148] In a half-cut dicing process, the depth of the cut made in the resin-coated semiconductor wafer can be appropriately selected according to the desired thickness of the semiconductor chip.

[0149] A semiconductor wafer with a resin film, which has been cut using a half-cut method, is subjected to a resin film removal process, in which the resin film is removed. The resin film removal process in this embodiment is the same as the resin film removal process in the first embodiment described above, except that the semiconductor wafer has been cut using a half-cut method (i.e., it has not been separated into semiconductor chips at this point).

[0150] After the resin film process, the semiconductor wafer is transferred from the dicing tape to a substrate such as a backgrind tape, and then subjected to the backgrind process in the form of a laminate comprising the semiconductor wafer and the substrate. If the dicing tape is UV-curable, a UV irradiation step may be provided before the transfer, in which the adhesive layer of the dicing tape is irradiated with ultraviolet light. The substrate to which the semiconductor wafer is transferred can be the same as the substrate used in the backgrind process of the first embodiment described above.

[0151] In the backgrinding process, the side of the semiconductor wafer without cuts (the back side) is ground until the cuts are reached (until it is separated into individual semiconductor chips). At this time, the side opposite to the grinding side (the circuit formation side) is covered by the substrate, so the adhesion of foreign matter such as grinding dust to the circuit formation side can be sufficiently suppressed.

[0152] After the backgrinding process, the substrate is removed to obtain a plurality of semiconductor chips having the desired thickness. The thickness of the back-ground semiconductor wafer is thinner than the thickness of the semiconductor wafer before backgrinding, and may be, for example, 10 to 1000 μm, 20 to 900 μm, or 30 to 800 μm. Furthermore, the method of removing the substrate is not particularly limited. For example, the individual semiconductor chips may be separated from each other, and the semiconductor chips pushed up from the substrate side with a needle may be picked up from the substrate by suction with a suction collet.

[0153] The semiconductor device manufacturing method of this embodiment may further include, similar to the first embodiment, a semiconductor chip bonding step in which a picked-up semiconductor chip and a support member are bonded together by heat and pressure via an adhesive layer (such as a die bonding film), and a heat curing step in which the adhesive layer is heat-cured.

[0154] The present disclosure will be described in more detail below with reference to examples. However, the present invention is not limited to these examples.

[0155] [Preparation of Evaluation Samples] <Synthesis of Polythiol Compounds> (Preparation of Raw Materials) The following raw materials were prepared: ・Polythiol compound having a disulfide bond X-1: Thiocol LP-3 (dithiol compound, manufactured by Toray Fine Chemicals Co., Ltd., weight-average molecular weight: 1000) ・Cyclic ether compound having a polyether group and two or more cyclic ether groups X-2: Denacol EX-861 (oxirane compound, number of oxirane groups: 2, manufactured by Nagase ChemteX Corporation, epoxy equivalent: 551 g / eq) ・Curing accelerator X-3: UCAT SA-1 (salt compound of 1,8-diazabicyclo[5.4.0]undeca-7-ene, manufactured by Sunapro Co., Ltd.)

[0156] (Synthesis of Polythiol Compound) 115.9 g of (X-1) and 83.7 g of (X-2) were weighed into a flask so that the equivalent ratio of thiol groups to epoxy groups was 3:2. The flask was heated to 100°C while stirring under a nitrogen atmosphere with a flow rate of 50 mL / min and a stirring blade rotation speed of 200 rpm. When the contents of the flask stabilized at 100°C, (X-3) was added. The amount of (X-3) added was adjusted to 2000 ppm based on the total amount of (X-1) and (X-2). While maintaining the contents of the flask at 100°C, the contents of the flask were sampled as needed to measure the thiol concentration, and the reaction was terminated when the thiol concentration reached 33% of the added amount to obtain the dithiol compound (A-2). The weight-average molecular weight (Mw) of the dithiol compound (A-2) was 5000.

[0157] Mw was measured by gel permeation chromatography (GPC) and derived by conversion using a calibration curve for standard polystyrene. The GPC conditions are as follows: Measurement device: SHOWDEX® GPC-101 (manufactured by RESONAC Corporation) Detector: SHOWDEX RI-71S differential refractometer (manufactured by RESONAC Corporation) Column: SHOWDEX LF-804 + LF-804 (manufactured by RESONAC Corporation) Column temperature: 40°C Eluent: Tetrahydrofuran (THF) Flow rate: 1 mL / min

[0158] <Preparation of Thermosetting Composition Varnish> (Preparation of Raw Materials) The following raw materials were prepared. (A) Component: Polythiol compound having a disulfide bond and a hydroxyl group A-1: ​​The above dithiol compound (A-1) (B) Component: Cyclic ether compound having a polyether group and two or more cyclic ether groups B-1: Denacol EX-861 (oxirane compound, number of oxirane groups: 2, manufactured by Nagase ChemteX Corporation, epoxy equivalent: 551 g / eq) B-2: Denacol EX-614B (oxirane compound, number of oxirane groups: 4, manufactured by Nagase ChemteX Corporation, epoxy equivalent: 167 g / eq) (C) Component: Curing accelerator C-1: UCAT SA-1 (salt compound of 1,8-diazabicyclo[5.4.0]undeca-7-ene, manufactured by Sunapro Co., Ltd.) (D) Component: Photoradical generator D-1: Omnirad379EG (2-dimethylamino-2-(4-methylbenzyl)-1-(4-molifolin-4-ylphenyl)-butan-1-one, manufactured by IGM Resins B.V.) (E) component: solvent E-1: ethyl lactate (F) component: curing accelerator inhibitor F-1: 2-ethylhexanoic acid

[0159] (Preparation of curable composition varnish) Components (A), (B), and (D) of the type and amount (unit: parts by mass) listed in Table 1 were added to an ointment jar, and the mixture was mixed for 90 seconds at 2000 revolutions per minute using a rotary agitator (manufactured by Thinky Co., Ltd., product name: Foam Remover Rentaro ARE-310), and then heated at 100°C for 30 minutes. After cooling, the mixture in the ointment jar was transferred to a screw bottle and diluted with component (E) to a solid content of 50% by mass. The diluted mixture was mixed in a vortex mixer, and when the solid content was uniformly dissolved, components (C) and (F) of the type and amount (unit: parts by mass) listed in Table 1 were added to obtain a curable composition varnish.

[0160]

[0161] <Preparation of Evaluation Samples> A silicon wafer (oxide-coated wafer, 6 inches, thickness: 625 μm) was fixed to a spin coater, and the above curable composition varnish was dropped onto the silicon wafer. Spin coating was performed at two rotation speeds to form a coating film with a thickness of 3 to 5 μm. The first spin coating was performed at a rotation speed of 500 rpm and a time of 5 seconds. The second spin coating was performed at a rotation speed of 1000 rpm and a time of 30 seconds to control the thickness of the coating film. Subsequently, the silicon wafer after film formation was placed on a hot plate and the solvent was removed at a temperature of 80°C and a time of 5 minutes to form a curable composition layer, and then N ２ A semiconductor wafer with a resin film was obtained by heating it in an oven at a temperature of 100°C for 120 minutes. Furthermore, a dicing tape was attached to the side of the silicon wafer opposite to the resin film, and an evaluation sample was prepared having the dicing tape, silicon wafer, and resin film in this order. The elastic modulus of the above resin film (photomeltable resin) was 85,000 Pa.

[0162] [Example 1] <Dicing Process> Using the evaluation sample described above, a dicing resistance test was performed using a dicing saw (DISCO Corporation, product name: DFD6361) and a dicing blade (DISCO Corporation, product names: Z1: ZH05-SD2000-N1-110FF, Z2: ZH05-SD4000-N1-70BB). A half-cut method was adopted, with the cut made from the resin film side, and the cut depth was 150 μm from the silicon wafer surface. The cooling water flow rate was 1.0 L / min. Under these conditions, dicing was performed so that the chip size was 5 mm vertically and 5 mm horizontally.

[0163] <Resin Film Removal Process> Using a conveyor-type UV exposure system (manufactured by GS Yuasa Corporation), ultraviolet light was irradiated from the resin film side of the evaluation sample after the dicing process. The ultraviolet light irradiation was at an illuminance of 120 mW / cm². ２ and irradiation dose of 2000 mJ / cm ２The experiment was conducted under the following conditions. The irradiation conditions were determined using an illuminance meter (UVR-T1, manufactured by Topcon Techno House Co., Ltd.) with a 365 nm light receiver (UD-T36). Next, the evaluation samples, after irradiation with ultraviolet light, were spin-cleaned using the spinner cleaning unit built into the dicing saw. The spin cleaning consisted of two stages: cleaning at low speed (first cleaning step) followed by cleaning at high speed (second cleaning step). The rotation speed and time in the first and second cleaning steps are shown in Table 2. Furthermore, using a two-fluid cleaning method, water as the cleaning solution was discharged from the nozzle of the spinner cleaning unit together with compressed air, and the mist-like water was sprayed onto the resin film of the rotating evaluation sample.

[0164] <Evaluation of Foreign Matter Removal Performance> After drying the silicon wafer following the resin film removal process, the surface of the silicon wafer was observed using an automated wafer visual inspection system (manufactured by Takano Corporation, minimum detection size: 2.58 μm or larger). Chips containing one or more foreign matter and / or resin particles within a 5 mm square chip were classified as A (defective), and chips not containing foreign matter and / or resin were classified as B (good). The chip yield (the percentage of chips classified as good out of the total number of chips obtained from one silicon wafer, (number of B-class chips) / [(number of A-class chips) + (number of B-class chips)] × 100 (%)) was calculated. The results are shown in Table 2.

[0165] [Examples 2-4] The dicing process and resin film removal process were performed in the same manner as in Example 1, except that the first and second cleaning processes were performed at the rotation speeds and times shown in Table 2, and the foreign matter removal performance was evaluated. The results obtained are shown in Table 2.

[0166] [Comparative Examples 1-4] The dicing and resin film removal processes were performed in the same manner as in Example 1, except that the first cleaning process was performed at the rotation speed and time shown in Table 2, and the second cleaning process was omitted. The foreign matter removal performance was then evaluated. The results obtained are shown in Table 2.

[0167] [Comparative Example 5] The dicing process and resin film removal process were performed in the same manner as in Example 1, except that cleaning at high speed (first cleaning step) was followed by cleaning at low speed (second cleaning step). The rotation speed and time in the first and second cleaning steps are shown in Table 2. The foreign matter removal performance of the silicon wafer after the resin film removal process was evaluated in the same manner as in Example 1. The results obtained are shown in Table 2.

[0168]

[0169] 1... Semiconductor wafer, 1a... Semiconductor chip, 3... Resin film, 3a... Resin film piece, 5... Dicing tape, 7... Semiconductor wafer with resin film, 7a... Semiconductor chip with resin film piece, 9... Dicing blade, 13... Support member, 15... Adhesive layer, 20... Semiconductor device.

Claims

1. A method for manufacturing a semiconductor device, comprising: a dicing step of dicing a semiconductor wafer and a resin film-coated semiconductor wafer having a resin film disposed on the semiconductor wafer; a resin film removal step of removing the resin film from the resin film-coated semiconductor wafer after the dicing step, wherein the resin film contains a photo-meltable resin, and the resin film removal step includes a photo-melting step of irradiating the resin film with light to melt the photo-meltable resin; a first cleaning step of supplying an aqueous solvent to the resin film while rotating the resin film-coated semiconductor wafer at a first rotational speed; and a second cleaning step of supplying an aqueous solvent to the resin film while rotating the resin film-coated semiconductor wafer at a second rotational speed faster than the first rotational speed.

2. The method for manufacturing a semiconductor device according to claim 1, wherein the second rotational speed is 2 times or more but less than 10 times the first rotational speed.

3. The method for manufacturing a semiconductor device according to claim 1, wherein the first rotational speed is 200 rpm or more and 1000 rpm or less.

4. The method for manufacturing a semiconductor device according to claim 1, wherein the second rotational speed is 1,000 rpm or more and 2,000 rpm or less.

5. The method for manufacturing a semiconductor device according to claim 1, wherein the photomeltable resin comprises a reaction product of a polythiol compound having a disulfide bond and two or more thiol groups, and a compound having two or more functional groups that can react with thiol groups.

6. The method for manufacturing a semiconductor device according to claim 1, wherein the photomeltable resin comprises a reaction product of a polythiol compound having a disulfide bond and a hydroxyl group and two or more thiol groups, and a cyclic ether compound having a polyether group and two or more cyclic ether groups.

7. The method for manufacturing a semiconductor device according to claim 1, wherein the elastic modulus of the photomeltable resin is 200,000 Pa or less.

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