KR20110038339A - Protective film composition for laser dicing - Google Patents

Abstract

PURPOSE: A protective film composition for laser is provided to ensure excellent thermal stability, thereby avoiding the formation of a thermal crosslinking material by laser irradiation during a dicing process, and to secure excellent adhesion to a wafer. CONSTITUTION: A protective film composition for laser comprises (A) polyethyloxazoline, (B) at least one component selected from the group consisting of a water-soluble resin, a monomer of alcohols, and their mixture, (C) an antioxidant, (D) a water-soluble surfactant, and (E) a solvent. Polyethyloxazoline(A) and one kind of compound(B) selected from the group consisting of a water-soluble resin, a monomer of alcohols, and their mixture are included in a weight ratio of 1:9 - 7:3.

Description

Protective film composition for laser dicing

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective film composition for laser dicing, and more particularly, to a laser dicing protective film composition which is used in a laser dicing process of semiconductor devices and display devices, and which is excellent in thermal stability, coating property, storage stability, and the like.

The wafer dicing step in the semiconductor device manufacturing step is a step of separating each of the listed devices by cutting a boundary surface called a street after the semiconductor lamination step is completed. When the dicing process of the wafer is completed, the semiconductor device is completed.

At present, semiconductor devices are being integrated, thereby narrowing the distance between the streets and weakening the mechanical properties of the stacks. For example, the insulating film at the top of the stack in the integrated semiconductor device may be broken or damaged during the dicing process. Therefore, the dicing process is also changing from a process of cutting a wafer by a blade to a process using a blade after forming a groove in a wafer street using a laser. Moreover, the process of cutting a wafer using only a laser is also introduced. However, in a laser dicing process using a laser, fumes are generated and scattered by the heat of the laser, which causes a problem of contamination of the upper surface of the wafer.

In order to solve the problem, a known technique is applied to a water-soluble resin of polyvinyl alcohol, polyethylene glycol, and cellulose based on an upper surface of a wafer to form a protective film and to generate laser light. A processing method for investigating is disclosed.

However, the processing method has a disadvantage in that debris occurs along the wafer street when silicon gas is generated at the wafer cutting surface by the laser light. In addition, fume is generated along with silicon gas and accumulates on the wafer, which is a defect since the wafer protective film is not washed out after washing with water. In addition, water-soluble resins such as polyvinal alcohol have a disadvantage of poor thermal stability. In more detail, when the laser is irradiated during the laser dicing process, heat is generated internally, and thermal decomposition of the water-soluble resin occurs by the heat, thereby deteriorating thermal stability. In addition, crosslinking occurs during pyrolysis, and the thermal crosslinking material may remain on the upper surface of the wafer without being washed off with water after the laser dicing process, causing other problems.

On the other hand, a protective film for wafer dicing is generally formed by spin coating a protective film composition. At this time, the upper surface of the wafer is uneven and there are many irregularities. If the coating property of the protective film composition is bad, the stability of the protective film is lowered and the process margin is reduced.

Not only the manufacturing process of the semiconductor element but also the manufacturing process of the display element using the glass substrate has problems for the same reason as in the manufacturing process of the semiconductor element.

It is an object of the present invention to provide a protective film composition for laser dicing in which thermal crosslinking material is not produced by laser irradiation during the dicing process due to excellent thermal stability.

Moreover, the objective of this invention is providing the protective film composition for laser dicing which is excellent in adhesive force with a wafer, and has suitable hardness.

It is also an object of the present invention to provide a protective film composition for laser dicing in which a flaw does not occur on a wafer surface after washing the protective film with water after a grooving process by a laser.

 In addition, an object of the present invention is to provide a protective film composition for laser dicing excellent in coating properties and storage stability.

The present invention (A) polyethyloxazoline; (B) one component selected from the group consisting of water-soluble resins, monomolecules of alcohols and mixtures thereof; (C) antioxidants; (D) water soluble surfactants; And (E) it provides a protective film composition for laser dicing comprising a solvent.

The protective film composition for laser dicing of the present invention is excellent in thermal stability and does not generate a thermal crosslinking material due to laser irradiation during the dicing process. In addition, the protective film composition for laser dicing of the present invention has excellent adhesion with the wafer to prevent debris generated during the laser dicing process from adhering to the wafer surface. In addition, the protective film composition for laser dicing of the present invention by forming a protective film having an appropriate hardness, after the cleaning of the protective film with water after the grooving process does not cause defects on the wafer surface. In addition, the protective film composition for laser dicing of the present invention can be widely used in the dicing process of the manufacturing process of semiconductor devices and display devices having high integration because of excellent coating performance and storage stability for the wafer.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated.

(A) Polyethyloxazoline contained in the protective film composition for laser dicing of the present invention is excellent in thermal stability and solubility in water.

Examples of the (A) polyethyloxazoline include poly (2-ethyl-2-oxazoline), and a commercially available product includes aquasol (trade name).

The (A) polyethyloxazoline is a temperature rising rate of 10 ℃ / min under a nitrogen atmosphere when the weight loss is measured on a thermogravimetric analyzer (TGA) begins to appear weight loss at 350 ℃ or more and rapidly decomposed around 380 ℃ Happens. However, no crosslinking accompaniment is made during decomposition, so that no defects are produced that do not dissolve in water.

One component selected from the group consisting of (B) a water-soluble resin, a single molecule of alcohols, and a mixture thereof contained in the protective film composition for laser dicing of the present invention improves the adhesion between the protective film and the substrate, and the hardness of the protective film. Adjust.

The one component selected from the group consisting of (A) polyethyloxazoline, (B) water-soluble resin, monomolecules of alcohols and mixtures thereof is preferably included in a weight ratio of 1: 9 to 7: 3. Do. When it is contained in the above-mentioned range, the thermal stability of the protective film is excellent, the adhesion between the protective film and the wafer is improved, and the protective film has an appropriate hardness.

The water-soluble resin is preferably one or two or more selected from the group consisting of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), cellulose and polyacrylic acid (PAA).

If the water-soluble resin is included alone in the protective film composition for laser dicing, the thermal stability is weak due to the hydroxyl group or the carboxylic acid group contained in the water-soluble resin and cross-linking by-products are generated upon thermal decomposition. For this reason, it mixes with said (A) polyethyl oxazoline excellent in thermal stability, and is used.

Among the water-soluble resins, polyvinyl alcohol has good solubility in water and excellent adhesion to wafers. Therefore, when the (A) polyethyl oxazoline and polyvinyl alcohol are mixed and used, the adhesive force of the protective film composition for laser dicing can be improved. For this reason, the lifting phenomenon of a protective film can be prevented at the time of laser irradiation.

The polyvinyl alcohol has a solubility in water according to the saponification degree and the molecular weight, and thus the storage stability and the stability with time after dissolution are different, so that the saponification degree is 87 to 90% and the polyvinyl alcohol having a polymerization degree of 500 to 2,000 is used. It is desirable to. If saponification degree and polymerization degree satisfy | fill the above-mentioned range, there will be no viscosity change with time. If the above-mentioned range is exceeded, the solubility in water is not good and the viscosity increases with time because gelation proceeds after being dissolved in water.

The polyvinyl alcohol is preferably included so that the pH of the protective film composition for laser dicing of the present invention is 5.5 to 7.0. If it is less than the above-mentioned range, there is a disadvantage that more crosslinking by-products which are not dissolved by water at 250 ° C. or lower occur when the pH is 5.5 or more.

Among the water-soluble resins, polyvinylpyrrolidone (PVP) has good solubility in water and excellent thermal stability. When the weight loss of the polyvinylpyrrolidone (PVP) was measured in a thermogravimetric analyzer (TGA) at a temperature rising rate of 10 ° C./min under a nitrogen atmosphere, a weight loss began to appear at around 300 ° C. and suddenly at 400 ° C. Decomposition occurs. However, no cross-linking by-products are produced during decomposition, resulting in no defects that do not dissolve in water.

The single molecule of the alcohols is preferably one or two or more selected from the group consisting of monoethylene glycol, trisethylene glycol, tetraethylene glycol, pentaerythritol, and trismethylpropanol.

The alcoholic single molecules improve the cleaning property of the protective film.

(C) Antioxidant contained in the protective film composition for laser dicing of this invention raises the storage stability of a composition, and suppresses formation of a crosslinking by-product.

In more detail, generation | occurrence | production of the bridge | crosslinking by-product which arises in a process is suppressed by the 1 type component chosen from the group which consists of said (B) water-soluble resin, the monomolecule of alcohol, and a mixture thereof. In addition, the (C) antioxidant stabilizes radicals or electrons generated by light or heat in the laser dicing process in the protective film composition for laser dicing of the present invention to suppress the formation of crosslinking byproducts that are not dissolved by water. In addition, when the (C) antioxidant is included in the protective film composition for laser dicing of the present invention, polyvinyl alcohol in the water-soluble resin, when stored for a long time at a temperature higher than room temperature to form a crosslinking by-product that does not dissolve in water and gelation occurs To prevent them.

The (C) antioxidant is 100 parts by weight, which is the sum of the solid content of the one component selected from the group consisting of the above-mentioned (A) polyethyloxazoline, (B) water-soluble resin, alcohols, monomolecules and mixtures thereof. It is preferably included in 0.1 to 3.0 parts by weight. If the above range is satisfied, there is an advantage of excellent storage stability, thermal stability and process safety.

It is preferable that the said (C) antioxidant is water-soluble, and it is more preferable that it is a triazine derivative antioxidant.

The water-soluble surfactant (D) contained in the protective film composition for laser dicing of the present invention improves the coating property of the composition, prevents gelation of the composition, and improves storage stability.

In general, since the protective film used in the laser dicing process has a thickness of 0.5 μm or more and the surface of the wafer has a large curvature, when the coating property of the protective film composition is not good, a difference in the film thickness between the center and the edge of the wafer occurs. Process margins will be reduced. Therefore, the protective film composition of this invention improves the coating property of a composition by adding water-soluble surfactant.

The said (D) water-soluble surfactant is 100 weight part of the sum total of solid content of the 1 component chosen from the group which consists of said (A) polyethyloxazoline, said (B) water-soluble resin, a single molecule of alcohol, and mixtures thereof. With respect to, it is preferably included in 0.001 parts by weight to 0.008 parts by weight. If the above-mentioned range is satisfied, it is excellent in applicability | paintability, storage stability, and thermal stability, and there exists an advantage that the hardness of a protective film is suitable.

The (D) water-soluble surfactants include polyether-modified alkylsiloxanes, polyether-modified polyalkylsiloxanes, polydimethyl siloxanes of polyether-modified hydroxy functional groups, polyether-polyester-modified hydroxy polyalkylsiloxanes, and non-ionic polyacrylic-based water-soluble surfactants. It is preferable that it is 1 type, or 2 or more types chosen from the group which consists of an active agent, an alcohol alkoxylate, and a polymeric fluorine-type water-soluble surfactant.

The solvent (E) contained in the protective film composition for laser dicing of the present invention is included by adjusting the viscosity of the protective film composition for laser dicing of the present invention to 10 to 100 cP. When the viscosity range described above is satisfied, coating properties, storage stability, protective film and wafer adhesion are excellent, and the hardness of the protective film is appropriate.

The solvent (E) is preferably one kind selected from the group consisting of water, an organic solvent and a mixture thereof. It is preferable that the said (E) solvent is a mixture of water and an organic solvent for film thickness control, coating property, and storage stability of the protective film composition for laser dicing of this invention.

The organic solvent is one or two selected from the group consisting of isopropyl alcohol, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), butylene carbonate, propylene carbonate, glycerin carbonate and ethylene carbonate It is preferable that it is above.

Of the organic solvents, propylene glycol monomethyl ether has excellent compatibility with water, so that it can be dissolved with water at any mixing ratio, but propylene glycol monomethyl ether acetate is dissolved in only 16 g or less with respect to 100 g of water. do. In addition, when a mixture of organic solvents such as butylene carbonate, propylene carbonate, glycerin carbonate, and ethylene carbonate having a high polarity is used in combination, it has an advantageous effect in terms of storage stability and coating property. The ethylene carbonate is well soluble in solid or water at room temperature, glycerin carbonate can be dissolved in water at any mixing ratio. However, butylene carbonate and propylene carbonate should be used within this range because the solubility in water is less than 10% and 25% at room temperature, respectively.

It is preferable that pHs of the protective film composition for laser dicing of this invention are 5.5-7.0.

The protective film composition for laser dicing of the present invention may further include one or more additives known in the art to improve performance. In particular, the protective film composition for laser dicing of the present invention may further include an antifoaming agent as an additive in order to suppress the foaming of the solution, such antifoaming agents include polysiloxane, polyalkylsiloxane, fluorosilicone polymer and the like.

The present invention also relates to a semiconductor device and a display device produced using the above protective film composition for laser dicing. The semiconductor device according to the present invention is completely protected by the wafer dicing protective film according to the present invention even when dicing a wafer using a laser, a blade, etc., and the cleaning of the protective film is also easy, so that there is no defect. Characterized in that manufactured.

Hereinafter, the present invention will be described in more detail using examples. However, the following examples are provided to illustrate the present invention, and the present invention is not limited to the following examples and may be variously modified and changed.

Examples 1 to 6 and Comparative Examples 1 to 3: Preparation of protective film composition for laser dicing

The ingredients shown in Table 1 were added to the mixing tank equipped with the stirrer as described in the contents, and the solution had a viscosity of 60 cP while introducing water into the solvent. This was stirred at a speed of 500 rpm for 1 hour at room temperature to prepare a protective film composition for laser dicing. At this time, polyethylol sazoline, polyvinyl alcohol, and polyvinylpyrrolidone were converted into solid content.

(A) component
(g) (B) component
(g) (C) component
(g) (D) component
(g) additive
(g) Example 1 A-1 5 B-1 5 C-1 0.05 D-1 0.0003 F-1 0.0003 Example 2 A-1 5 B-1 5 C-2 0.05 D-1 0.0003 F-1 0.0003 Example 3 A-1 5 B-1 5 C-3 0.05 D-1 0.0003 F-1 0.0003 Example 4 A-1 5 B-1 5 C-4 0.05 D-1 0.0003 F-1 0.0003 Example 5 A-1 2 B-2 / B-3 6/2 = 8 C-1 0.05 D-1 0.0003 F-1 0.0003 Example 7 A-1 3 B-2 / B-4 / B-5 7/1 / 0.3 = 8.3 C-1 0.05 D-1 0.0003 F-1 0.0003 Comparative Example 1 A-1 5 B-1 5 - - D-1 0.0003 F-1 0.0003 Comparative Example 2 A-1 2 B-2 / B-3 6/2 = 8 - - D-1 0.0003 F-1 0.0003 Comparative Example 4 A-1 3 B-2 / B-4 / B-5 7/1 / 0.3 = 8.3 - - D-1 0.0003 F-1 0.0003

A-1: Polyethyl oxazoline (Brand name: Aquasol, Manufacturer: ICP, Degree of polymerization: 50)

B-1: polyvinyl alcohol (polymerization degree: 500, saponification degree: 87 to 90%)

B-2: polyvinyl alcohol (polymerization degree: 1700, saponification degree: 87 to 90%)

B-3: polyvinylpyrrolidone (polymerization degree: 1200)

B-4: triethylene glycol

B-5: Butylene Carbonate

C-1: antioxidant (trade name: TINUVIN99DW, manufacturer: Ciba)

C-2: Antioxidant (trade name: TINUVIN123DW, manufacturer: Ciba)

C-3: antioxidant (trade name: TINUVIN400DW, manufacturer: Ciba)

C-4: antioxidant (trade name: TINUVIN477DW, manufacturer: Ciba)

D-1: Surfactant (brand name: BYK-337, manufacturer: BYK)

F-1: Defoamer (Brand name: BYK-025, Manufacturer: BYK)

Test Example: Evaluation of Properties of Protective Film Composition for Laser Dicing

<Storage Stability Test>

The compositions of Examples 1 to 6 and Comparative Examples 1 to 3 were stored at room temperature and 40 ° C. to measure viscosity and coatability every week to determine whether changes in physical properties over time occurred. The test results are shown in Table 2 below.

◎: stable for more than 36 weeks

○: stable for more than 24 weeks

△: stable for more than 12 weeks

X: stable under 12 weeks

<Adhesive test>

Samples were prepared by spin coating the compositions of Examples 1 to 6 and Comparative Examples 1 to 3 on a 4 inch silicon oxide substrate and drying at 110 ° C. for 5 minutes to adjust the spin rate (rpm) so that the film thickness was 1 μm. Was prepared. Thereafter, a crosscut test (tapping test) was conducted according to the experimental method of JIS K5600-5-6. The test results are shown in Table 2 below.

◎: number of grids dropped (0)

○: number of grids dropped (1-5)

△: Number of fallen grids (5-10)

×: number of fallen grids (10 or more)

<Thermal Stability Test>

After spin coating the compositions of Examples 1 to 6 and Comparative Examples 1 to 3 on a 4 inch silicon oxide substrate, the spin rate (rpm) was adjusted so that the film thickness dried at room temperature for 5 minutes was 1 μm. Was prepared. After the baking for 10 minutes at 300 ℃ in a hot air dryer, it was confirmed whether washed out with water. This is a test to check whether pyrolytic crosslinking material that is insoluble in water is generated by heat. The test results are shown in Table 2 below.

◎: stripped clean

○: fine particles present

△: many unstriped parts

×: not stripped at all

Storage stability Adhesion Thermal stability 23 ℃ 40 ℃ Example 1 ◎ ◎ ◎ ◎ Example 2 ◎ ◎ ○ ◎ Example 3 ◎ ◎ ○ ◎ Example 4 ◎ ◎ ◎ ◎ Example 5 ◎ ◎ ◎ ◎ Example 6 ◎ ◎ ◎ ◎ Comparative Example 1 ○ △ ○ ○ Comparative Example 2 ○ △ ◎ ○ Comparative Example 3 ○ X ◎ ◎

Claims (13)

(A) polyethyloxazoline; (B) one component selected from the group consisting of water-soluble resins, monomolecules of alcohols and mixtures thereof; (C) antioxidants; (D) water soluble surfactants; And (E) A protective film composition for laser dicing comprising a solvent. The method according to claim 1, The one component selected from the group consisting of (A) polyethyloxazoline, (B) water-soluble resins, alcohols, monomolecules and mixtures thereof is contained in a weight ratio of 1: 9 to 7: 3. A protective film composition for laser dicing to be. The method according to claim 1, To 100 parts by weight that is the sum of solids of one component selected from the group consisting of (A) polyethyloxazoline, (B) water-soluble resin, alcohols, monomolecules and mixtures thereof, 0.1 to 3.0 parts by weight of the (C) antioxidant; And The protective film composition for laser dicing, characterized in that the (D) water-soluble surfactant is contained in 0.001 parts by weight to 0.008 parts by weight. The method according to claim 1, The solvent (E) is a laser dicing protective film composition, characterized in that it comprises a viscosity of 10 to 100 cP of the protective film composition for laser dicing. The method according to claim 1, The protective film composition for laser dicing, characterized in that the pH of the protective film composition for laser dicing is 5.5 to 7.0. The method according to claim 1, The water-soluble resin is one or two or more selected from the group consisting of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), cellulose and polyacrylic acid (PAA) A protective film composition for laser dicing. The method according to claim 1, The monomolecular molecules of the alcohols are one or two or more selected from the group consisting of monoethylene glycol, trisethylene glycol, tetraethylene glycol, pentaerythritol, and trismethylpropanol. The method according to claim 1, The protective film composition for laser dicing, wherein the (C) antioxidant is a triazine derivative antioxidant. The method according to claim 1, The (D) water-soluble surfactants include polyether-modified alkylsiloxanes, polyether-modified polyalkylsiloxanes, polydimethyl siloxanes of polyether-modified hydroxy functional groups, polyether-polyester-modified hydroxy polyalkylsiloxanes, and non-phosphorous polyacrylic-based water-soluble surfactants. A protective film composition for laser dicing, characterized in that one or two or more selected from the group consisting of an activator, an alcohol alkoxylate, and a polymeric fluorine-based water-soluble surfactant. The method according to claim 1, The solvent (E) is a laser dicing protective film composition, characterized in that one kind selected from the group consisting of water, organic solvents and mixtures thereof. The method according to claim 10, The organic solvent is one or two selected from the group consisting of isopropyl alcohol, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), butylene carbonate, propylene carbonate, glycerin carbonate and ethylene carbonate The protective film composition for laser dicing characterized by the above. The semiconductor device manufactured using the protective film composition for laser dicing of Claim 1. The display element manufactured using the protective film composition for laser dicing of Claim 1.