JPH03203981A - Adhesive agent, cleansing agent for wafer or the like and method and device for treating with the same - Google Patents

Abstract

PURPOSE:To provide the subject adhesive having excellent stain resistance and useful for wafers, etc., by mixing rosin or a resin containing as a main component a tricyclic compound represented by abietic acid, a derivative thereof or a modified product thereof with a dibasic acid in the adhesive. CONSTITUTION:One kind or more of a resin such as rosin containing a tricyclic compound represented by abietic acid as a main component, a rosin ester which is a derivative of the resin, partially or perfectly hydrogenated rosin, polymerized rosin, a dibasic acid-modified rosin which is a modified product of the resin with a dibasic acid such as maleic acid, an ester thereof, etc., are mixed (so as to give an acid value of >= approximately 70) to provide the objective adhesive. The addition of natural or synthetic shellac to the adhesive permits to heighten the cleansability of the adhesive.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to adhesives used in the processing of wafers such as silicon wafers, cleaning agents for cleaning the adhesives, and wafers using these adhesives. The present invention relates to a processing method and an apparatus therefor.

(Prior Art) When performing various processing such as polishing on a wafer such as silicon, gadolinium gallium garnet, gallium arsenide, gallium phosphide, sapphire, crystal, glass, ceramic, magnetic material, etc., this wafer It is necessary to fix it, that is, temporarily fix it, to a plate etc. during the processing process so that it does not move.

Conventionally, such adhesives have mainly been thermoplastic, such as vinyl polymer compounds, petroleum resins, paraffin wax, etc., so that they can be applied thinly and uniformly. Such adhesives can be removed using halogenated organic solvents such as trichlorethylene, aromatic hydrocarbons, flammable solvents, and oxidizing cleaning agents that are a mixed solution of strong acids, strong alkalis, and hydrogen peroxide. , has been washed.

However, when cleaning objects such as wafers and plates with halogenated organic solvents such as trichlorethylene to remove the adhesive, the surface of the wafers becomes hydrophobic, and the cleaning effect is reduced in water cleaning in the post-process. In order to eliminate this defect, the surface of the wafer or the like must be made hydrophilic using a hydrophilic solvent such as alcohol or acetone prior to washing with water.

Furthermore, the use of organic solvents has serious environmental health problems such as air pollution and destruction of the natural environment, and has also become a social problem. Furthermore, flammable solvents also pose a great risk of disasters such as fire, and explosion-proof equipment must be installed as a disaster prevention measure. Further, oxidizing detergents have a short cleaning life and are expensive. Moreover, all cleaning agents are toxic to the human body and contaminant, and there are various problems in their handling and working environment. Furthermore, when cleaning with these solvents, the high volatility causes the sea urchins, etc. to dry out, resulting in the contaminants becoming more firmly attached to the wafers, etc.

(Problems to be Solved by the Invention) The present invention provides an adhesive, a cleaning agent, a processing method, and an apparatus that eliminate the above-mentioned drawbacks and can clean adhesives smoothly and safely without using organic solvents. It is an attempt to obtain.

(Means for Solving the Problems) As a result of intensive research to solve the above problems, the present inventors have developed an adhesive that is soluble in aqueous alkaline solutions that can be cleaned without using an organic solvent, and a cleaning agent that is made of aqueous alkaline solutions. The present inventors have discovered that these problems can be solved and even better results obtained by using the present invention, and the present invention has been completed.

The above adhesive contains abietic acid (molecular formula C3゜H8゜O
There are resins such as rosin whose main component is a three-membered ring compound represented by monocarboxylic acid II).

Further, there are rosin esters, partially or fully hydrogenated rosins, and polymerized rosins, which are derivatives of the resins. Furthermore, there are dibasic acid-modified rosins, which are denatured products of the above resins and dibasic acids such as maleic acid, and derivatives such as esters thereof. These adhesives may be used alone, or may be used in combination of two or more of them. Generally, it is preferable that these components have an oxidation value larger than about 70, and if the oxidation value is smaller than this, the degree to which the alkaline detergent described below can cleanly clean the product will be lowered.

Natural shellac, which is a natural resin, or synthetic shellac, which is a polyester compound of trihydroxypalmitic acid and higher aliphatic dibasic acid, may be further added to the adhesive and mixed. The blending ratio of these natural or synthetic shellacs to the total is usually preferably about 40% or less; if it is more than this, the adhesive force will be too strong or the melt viscosity will be too high when used for wafers. It is often unsuitable for precision machining.

In addition, in order to adjust the softening point, viscosity, spreadability, etc. of the adhesive, glycols such as polyethylene glycol and polypropylene glycol, dibasic acid glyceride, polyvinylpyrrolidone, polyvinyl alcohol, ethyl cellulose, and other water-soluble compounds are added to the adhesive. , plasticizers such as phthalate esters, sebacate esters, and phosphate esters, dibasic acids such as maleic acid, fatty acids such as myristic acid and palmitic acid, other organic acids, and surfactants alone. It may be added separately or in combination as appropriate. In this case, for palmitic acid, approximately 1
When the amount of the adhesive is increased, such as when more than 5% is used, the adhesive often becomes soft, and there is a risk that the wafer may shift during processing.

In addition to being used as a mixture or composition as described above, these adhesives may also be used after being dissolved in an organic solvent so that the concentration of the composition is about 1 to 60%.

In this case, if the concentration is lower than the above, it will be difficult to obtain a coating film necessary for adhesion, and if the concentration is lower than 1. N makes it difficult to obtain a uniform coating film. The above organic solvents include lower alcohols, ketones, esters, aromatic solvents such as toluene and xylene, trichlene, and 1.1.1)! There are chlorinated solvents such as lchloroethane.

This adhesive is applied to the wafer \- to affix the wafer 1- to a plate, or is applied to a plate to affix a wafer.

After the wafer is attached to the plate and the wafer is polished, etc., the wafer is peeled off from the plate, and the adhering adhesive is dissolved and removed by the cleaning agent 1.

Such cleaning agents include, for example, organic alkalis that are compatible with water, such as alkanolamines, amino alcohols, and water-soluble amines. Further, for example, there are inorganic alkalis such as caustic soda and caustic potash, and inorganic alkali salts such as silicates and carbonates.

The alkalis and alkali salts mentioned above can be mixed and used as appropriate. This alkaline agent usually has a total amine content of about 1 to 15% in the form of a cleaning agent concentration liquid.
If the content is less than this, the cleaning effect will be low, and if it is more than this, it will tend to attack the wafer being processed.

The above cleaning agent may further contain one or more of lower alcohols such as methanol, ethanol, propatool, and isopropyl alcohol, polyhydric alcohols, and polysaccharides that are compatible with water. I have something to add.

Further, in order to modify the surface of the adhesive or increase its permeability, an ionic or nonionic surfactant may be further mixed.

For example, if a water-soluble polymeric substance such as methylcellulose or carboxymethylcellulose is further added, the dirt that falls off during cleaning can be stably dispersed in the cleaning agent, preventing it from re-adhering to the object to be cleaned, such as a wafer. It is particularly effective. These are typically about 0.01 at their working concentration.
It is often preferable to use a mixture of about 0.1%.

Further, in order to prevent etching of the wafer, ammonium acetate or the like may be added, and the amount added is usually about 0.1 to 1%.

The above-mentioned cleaning agents are usually used diluted to an appropriate concentration, but are often used as an aqueous solution diluted with water about 2 to 50 times.

(Example) [Example of adhesive] (Example 1) 80 parts of rosin with an oxidation value of 100 or more and 20 parts of maleic acid modified rosin were heated and stirred at a temperature of 120 to 200°C until melted. was cooled to room temperature to obtain an adhesive.

This is a heat-melting adhesive, and its softening point is determined according to JIS
-5909 (E1 ball method) measured at 70℃
Met. When stainless steel plates were bonded together using this adhesive, the adhesive strength was 20 kg/d.

(Example 2) The blending ratio was changed from Example 1 above, and 20 parts of rosin with an oxidation value of 100 or more and 80 parts of maleic acid modified gin were added in 120 to 100 parts.
The adhesive was heated and stirred until it melted within a range of 200 tons, and then cooled to room temperature to obtain an adhesive.

This is a hot-melt adhesive with a softening point of 130.
It was ℃.

(Example 3) An adhesive was obtained in the same manner as in Example 1 except that 10 parts of palmitic acid was further added.

This is a hot-melt adhesive with a softening point of 60°C.
Met.

(Example 4) In the above Example 2, palmitic acid was further added to Loll.
In addition, an adhesive was obtained in the same manner.

This is a hot-melt adhesive with a softening point of 75°C.
Met.

(Example 5) An adhesive was obtained in the same manner as in Example 1 except that 15 parts of palmitic acid was further added.

This is a hot-melt adhesive with a softening point of 45°C.
Met.

(Example 6) An adhesive was obtained in the same manner as in Example 2 except that 15 parts of palmitic acid was further added.

This is a hot-melt adhesive with a softening point of 65°C.
Met.

(Example 7) 70 parts of rosin with an oxidation value of 100 or more and 30 parts of natural lac
The mixture was heated and stirred at a temperature of 120 to 200° C. until melted, and then cooled to room temperature to obtain an adhesive.

This is a heat-melting adhesive, and its softening point was measured to be 70°C. Also, when stainless steel plates were bonded together using this adhesive, the adhesive strength was 60k.
g/-.

(Example 8) The adhesive obtained in Example 1 above was dissolved in methanol with a solid content of 20
% to obtain a liquid adhesive.

The adhesives of Examples 1 to 7 exhibited good adhesive properties and were suitable as adhesives. In addition, the adhesive of Example 8 was
By applying with a spin coater, spray, etc., and volatilizing the solvent component by heating with a hot plate, oven, etc., a coating film with a uniform thickness could be obtained, and the adhesion accuracy could be improved.

Furthermore, by adjusting the solid content concentration, the coating film thickness could be changed. Furthermore, the adhesives described in Examples 2 to 7 were obtained in the same manner as in Example 8, and the same good results as in Example 8 were obtained in all cases.

[Example of cleaning agent]

(Example 1) 30 parts of triethanolamine, 10 parts of aminoethylethanolamine, N-methyljetanolamine 51B,
A cleaning agent was obtained by mixing 0.1 part of a nonionic surfactant and 55 parts of pure water. When this was diluted 10 times and a silicon wafer using the adhesive obtained in Example 8 was immersed therein at room temperature, the adhesive could be dissolved and cleaned in about 2.5 minutes. Furthermore, cleaning can be speeded up by circulating this diluted solution or by using heating or ultrasonic waves in combination.

(Example 2) In the same manner as in Example 1 above, when the diluted solution was diluted 20 times and a silicon wafer was immersed at room temperature, the adhesive could be dissolved and cleaned in about 4.5 minutes.

(Example 3) A cleaning agent was obtained by mixing 30 parts of aminoethylethanolamine, 15 parts of N-methyljetanolamine, 10 parts of isopropyl alcohol, 0.1 part of a nonionic surfactant, and 45 parts of pure water. When this was diluted 10 times and a silicon wafer using the adhesive obtained in Example 8 was immersed therein at room temperature, the adhesive could be dissolved and cleaned in about 2.5 minutes. Furthermore, if this diluted solution is seeded in grooves or combined with heating or ultrasonic waves, cleaning will be faster.

(Example 4) In the same manner as in Example 3 above, when the diluted solution was diluted 20 times and a silicon wafer was immersed at room temperature, the adhesive could be dissolved and cleaned in about 4.5 minutes.

(Example 5) Aminoethylethanolamine 40! B, N-methyljetanolamine 51S, isopropyl alcohol 10
45B of pure water were mixed to obtain a cleaning agent. When this was diluted 10 times and a silicon wafer using the adhesive obtained in Example 8 was immersed therein at room temperature, the adhesive could be dissolved and cleaned in about 3 minutes. Furthermore, cleaning can be speeded up by circulating this diluted solution or by using heating or ultrasonic waves in combination.

(Example 6) In the same manner as in Example 5 above, when the diluted solution was diluted 20 times and a silicon wafer was immersed at room temperature, the adhesive could be dissolved and cleaned in about 5 minutes.

(Example 7) A cleaning agent was obtained in the same manner as in Example 1 except that 0.5B of carboxymethylcellulose was further added.

When this was washed in the same manner as in Example 1, the degree of re-adhesion of dirt such as adhesive in the washing liquid was smaller than that of Example 1.

(Example 8) A cleaning agent was obtained in the same manner as in Example 3 except that 2 parts of ammonium acetate was further added.

When this was similarly cleaned, etching of the silicon wafer could be further prevented compared to that of Example 3.

An apparatus for cleaning wafers with the above cleaning agent after processing such as polishing is shown in FIGS. 1 and 2.

To clean a wafer with the above-mentioned adhesive attached, it is possible to put only the wafer in a cleaning tank and clean it, but in the figure, the wafer is placed in a cassette and the cassette is immersed in the cleaning tank. It's Nishide.

As shown in FIG. 1, on the side of the apparatus main body 1 there is a cassette 20 containing wafers and a loader section 3. One or more cassettes are stored in the loader section, and a robot as shown in FIG. , 4, but they can also be conveyed manually.

The robot 4 is provided so as to be movable in the lateral direction along the main body 1, and has an elevating shaft 5, and a chuck head 6 for gripping the cassette at the tip of the elevating shaft.

A cleaning tank filled with the cleaning liquid is provided adjacent to the loader section. In the drawing, the adhesive cleaning tank includes a first cleaning tank 7 and a second cleaning tank 8 arranged side by side, but only one tank or three or more tanks may be provided.

The cleaning tank 7.8 is made of a suitable synthetic resin material so as not to be attacked by the above-mentioned cleaning solution, which is an alkaline aqueous solution, and the interior thereof is partitioned by a partition wall 9, one room being a cassette immersion chamber 1O and the other room being a cassette immersion chamber 1O. A heating chamber 11 is provided, and a heater 12 is provided to appropriately warm the cleaning liquid overflowing from the immersion chamber 10. The heating chamber 11 and the immersion chamber 10 are
The cleaning liquid is communicated via a pump 13 and a filter 14 to filter and circulate the cleaning liquid from the heating chamber 11 to the immersion chamber 10. Preferably, the inflow part for the cleaning liquid provided at the bottom of the immersion chamber 10 is formed by a porous plate 15 so that the cleaning liquid is sprayed almost uniformly from the entire lower part of the immersion chamber 10. Furthermore, it is also possible to bubble with nitrogen or gas or apply ultrasonic vibrations to give the cleaning liquid a vibration.

Further, the first cleaning tank 7 is connected to a second cleaning tank 8 via a pump 16, and when the cleaning liquid in the first cleaning tank becomes dirty, it is discarded and the cleaning liquid in the second cleaning tank is replaced. It is arranged to be transferred to the first cleaning tank. Near the cleaning tank,
Although not shown, a pure water supply port and a hand shower 17 are provided.

Since the surface of the wafer cleaned by the cleaning liquid is hydrophilic, the cleaning apparatus of the present invention is equipped with the cleaning tank 7.
A pure water cleaning tank is provided adjacent to the tank. Various devices can be provided as the pure water cleaning tank. A pure water cleaning tank 18 shown in FIG. 3 spouts pure water, warm pure water, etc. from a spout 21 at the bottom of the tank toward the wafers 20 of the cassette into an overflow tank 19 that stores the cassette, and also supplies pure water above the tank. Pure water is jetted onto the wafer from the shower nozzle 22, and the pure water overflows to wash the wafer, and the drain valve 23 provided at the bottom is opened at an appropriate time to drain the pure water, and then the drain valve 23 is drained again. , and the above operation is repeated.

Furthermore, what is shown in FIG. 4 is a cascade of pure water washing tanks 24, in which pure water is sequentially caused to flow from one chamber 25 to the other chamber 26 and circulated.

The apparatus shown in FIG. 1 has the pure water cleaning tank 18 and the pure water cleaning tank 24 adjacent to each other, but a cascade of three or more stages or a plurality of pure water cleaning tanks 18 may be provided. You can also do that.

An unloader section 27 is provided following the pure water cleaning tank, and is preferably used as an underwater unloader so that the wafer after cleaning is placed under the water surface.

When the robot 4 grips the cassette 2 containing the wafer and immerses it in the first adhesive cleaning tank 7, the adhesive adhering to the surface of the wafer is dissolved by the alkaline aqueous cleaning solution, and the cassette 2 containing the wafer is immersed in the first adhesive cleaning tank 7. By the time it is transferred to tank 8, it is completely removed.

Since the surface of the wafer is hydrophilic, it can be immediately transported to the pure water cleaning tank 18, 24 by the robot and cleaned with pure water (effects of the invention). Since no organic solvent is used in the cleaning solution, air pollution and other environmental health issues can be eliminated and the work can be used with peace of mind, and the workpieces cleaned with the cleaning solution are hydrophilic, making it easier to use than conventional methods. There is no need for treatment prior to washing with water, as in
It can be washed with pure water immediately and has good workability.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view, FIG. 2 is a sectional view, and FIG. 31! ! is an explanatory diagram of a pure water cleaning tank, and FIG. 4 is an explanatory diagram of a cascade pure water cleaning tank. 3: Loader section 7.8: Adhesive cleaning tank
18.24: Pure water cleaning tank 27: Unloader section

Claims (1)

[Scope of Claims] 1. A resin whose main component is a three-membered ring compound represented by rosin or other abietic acid, a derivative of the resin, or one or two modified products of the resin with a dibasic acid. An adhesive for wafers, etc. that is a mixture of the above. 2. The adhesive for wafers, etc. according to claim 1, further comprising natural or synthetic shellac. 3. The adhesive for wafers and the like according to claim 1 or 2, further comprising one or more of a softening point regulator, a viscosity regulator, or a spreadability regulator. 4. An adhesive for wafers, etc., prepared by dissolving the adhesive according to any one of claims 1 to 3 in an organic solvent to a content of 1 to 50%. 5 Organic alkalis, inorganic alkalis that are compatible with water,
Or a cleaning agent for wafers, etc. that removes wafer adhesives made of one type of inorganic alkali salt or a mixture of two or more of these salts. 6. The cleaning agent for wafers, etc. according to claim 5, further comprising one of lower alcohols, polyhydric alcohols, and polysaccharides, or a mixture of two or more of these. 7. The cleaning agent for wafers, etc. according to claim 6, further comprising a surfactant. 8. The cleaning agent for wafers, etc. according to claim 7, further comprising methylcellulose, carboxymethylcellulose, or other water-soluble polymeric substance. 9. The cleaning agent according to any one of claims 5 to 8 above.
Washing solution diluted 50 times with water. 10. A wafer processing method, which comprises temporarily bonding a wafer and a plate with an adhesive soluble in an aqueous alkaline solution, processing the wafer, peeling the wafer from the plate, and cleaning the wafer with a cleaning solution of an aqueous alkaline solution. . 11 An adhesive cleaning tank filled with an alkaline aqueous solution cleaning solution to dissolve the alkaline aqueous solution soluble adhesive attached to the wafer, and a pure water cleaning tank adjacent to the adhesive cleaning tank to clean the wafer with pure water. A wafer cleaning device characterized by being equipped with a tank.