JP3443486B2 - How to remove resist - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an unnecessary resist material on an article such as a semiconductor substrate when manufacturing microfabricated parts such as semiconductors, circuits, various printed boards, various masks and lead frames. It concerns the method of removal.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, a resist material is applied onto a wafer, an image consisting of a resist pattern is formed by a normal photo process, and an etching is performed using this as a mask. Are removed to form a circuit. In order to form the next circuit, the resist material is applied again, and the cycle of image formation-etching-resist material removal is repeated. When forming circuits on various substrates, unnecessary resist material is removed after the resist pattern is formed.

Here, the unnecessary resist material is generally removed by an asher (ashing means) or a solvent (peeling solution). However, if an asher is used for removing the resist material, it may take a long time for the work and impurity ions in the resist material may be injected into the wafer, which is not preferable. Moreover, if a solvent is used,
There was a problem that it harmed the working environment.

Therefore, the applicant of the present application, for example, in Japanese Unexamined Patent Publication No. 4-345015, uses an adhesive sheet such as a sheet or tape for removing the resist material, which is used as a resist pattern. We have proposed a method in which it is attached to the upper surface of the photoresist and then peeled off integrally with the resist material. According to this method, when the impurity ions in the resist material are implanted into the wafer or the working environment is damaged, problems are avoided.

[0005]

However, according to the studies by the present inventors, in the method using the above-mentioned adhesive sheets,
A part or minute part of the resist material to be removed may remain on the article as it is without being peeled off, and it was difficult to peel off the entire surface without removing it.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a method for surely removing unnecessary resist material on an article by using adhesive sheets.

[0007]

Means for Solving the Problems The inventors of the present invention have diligently studied the above object, and as a result, in the peeling operation of the adhesive sheet, the resist material is partially left without being peeled off. It is thought that the cause is that the layer composed of the agent is not sufficiently adhered to the resist material, and based on this idea, a specific adhesion-imparting treatment was applied before the peeling operation. The problem of poor sex is avoided,
Knowing that we can achieve reliable stripping and removal of the resist material,
The present invention has been completed.

That is, the present invention provides a method of removing a resist in which a layer made of an adhesive is provided on an article having a resist pattern and the layer and the resist material are integrally peeled, prior to the above peeling. Adhesion is a process for applying adhesion that changes the layer made of an adhesive from a softened state to a solidified state.
The layer consisting of the agent is heated to a temperature above the glass transition point of the adhesive polymer.
After heating it to a softened state, the glass of the polymer
Cooling to a temperature below the transition point to a solidified state,
Swell the layer of adhesive or adhesive with water or solvent.
Or dissolve it to a softened state, then dry it with water or a solvent.
The present invention relates to a method for removing a resist, which comprises performing a treatment for drying and removing the solidified state to enhance the adhesion of this layer to a resist material.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the method of removing a resist of the present invention, first, on an article on which a resist pattern is present,
A layer of adhesive is provided. This method of providing may be carried out by a method of directly applying an adhesive onto the article, or by preparing adhesive sheets in the form of a sheet or tape from the adhesive in advance, The adhesive sheets may be attached to the above article. The thickness of the adhesive layer is not particularly limited, but is usually about 10 to 200 μm.
Is.

A substrate may be used here to reinforce the layer of adhesive. The use of the base material prevents breakage of the layer during the peeling operation, and facilitates efficient peeling of the resist material. When a base material is used, in the method of directly applying the adhesive onto the article, the base material may be attached to the application surface as a backing material. Further, in the method of adhering the adhesive sheets, a layer made of an adhesive may be provided on the base material to prepare sheet-shaped or tape-shaped adhesive sheets.

Examples of the material of the base material include polyethylene, polypropylene, polyethylene terephthalate, acetyl cellulose, polyimide, paper, cotton, hard or soft aluminum, stainless steel and glass. The shape of the substrate may be a film or a plate, and a porous substrate is particularly preferable. The porous base material enhances the bonding force between the base material and the layer made of an adhesive, and can prevent anchoring damage between the base material and the layer at the time of peeling the resist .

Adhesives include urea resin, phenol resin, epoxy resin, polyisocyanate, polyvinyl acetate, polyvinyl acetal, polyvinyl alcohol, poly (meth) acrylic acid ester, polycyanoacrylic acid ester. , polyamide, from among the various types of natural polymers, in particular
Swells or dissolves in thermoplastics, water or solvents
Well- known adhesives can be widely used, such as those having the property of being used as an adhesive polymer.

In the present invention, a layer made of such an adhesive is provided on an article, and an appropriate adhesion-imparting treatment depending on the type of the adhesive, that is, a layer made of the adhesive is provided before peeling the layer. A major feature is that an adhesion-imparting treatment for changing from a softened state to a solidified state is performed. Here, the above-mentioned "softened state" refers to a state where the viscosity becomes 10 ¹² poise or less.

[0014]

As one of the adhesion-imparting treatments , a layer made of an adhesive is heated to a temperature not lower than the glass transition point of the adhesive polymer to bring it into a softened state (flow within 10 seconds or less), and then the above-mentioned polymer is added. There is a treatment method of cooling to a temperature lower than the glass transition point to obtain a solidified state. In this treatment method, a thermoplastic resin is selected as an adhesive polymer, and a layer made of an adhesive using this is applied with heat to be softened,
It is cooled and solidified before the peeling operation.

As another one of the adhesion-imparting treatments, a layer made of an adhesive is swollen or dissolved with water or a solvent to make it a softened state (flow within 10 seconds or less), and then the water or the solvent is dried and removed. There is a treatment method that sets the solidified state. In this treatment method, an adhesive polymer having a property of swelling or dissolving in water or a solvent is selected, and various organic solvents can be used as the solvent. Water or a solvent may be contained in the adhesive in advance before forming a layer made of the adhesive on the surface of the resist material on the article, or may be supplied after the layer is formed. Good. The supply method may be either supply to the article surface or supply to the layer surface. It is preferable to use a porous material as the base material, because the above-mentioned supply becomes easy and the removal by drying becomes easy. Water or a solvent may be supplied in a liquid state or may be supplied as a vapor.

When such adhesion-imparting treatment is applied, the adhesion of the layer made of the adhesive to the resist material is remarkably enhanced. In this state, when the above layer has a substrate, the resist material on the article is peeled off together with the substrate, whereby the resist material on the article is easily and completely peeled off. That is, this stripping operation no longer causes problems when the resist material partially remains on the article.

[0018]

EXAMPLES Next, examples of the present invention will be described to more specifically describe.

Example 1 A 3-liter flask equipped with a stirrer was charged with 37.5 g of 2-ethylhexyl acrylate and 22.
5 g, 90 g of acrylic acid and 225 g of methanol were charged, the temperature was raised to 60 ° C. under a nitrogen gas atmosphere, 0.3 g of azobisisobutyronitrile was added as a polymerization initiator, and polymerization was carried out for 8 hours. The polymerization rate was about 100% by weight, and the weight average molecular weight of the obtained polymer was 200,000. This polymer solution was applied onto a polyester film having a thickness of 50 μm so that the thickness after drying would be 40 μm.
An adhesive sheet was prepared by drying at 0 ° C for 5 minutes.

On the other hand, a resist material composed of novolak and naphthoquinone diazide is applied to the surface of a silicon wafer (semiconductor substrate), heated, exposed and developed to form a resist pattern on the entire surface of the wafer, and then As ions are formed. At an acceleration energy of 80 KeV and a dose of 1 × 10 ¹⁶ i
It was injected over the entire surface at a concentration of ons / cm ³ .

The pressure sensitive adhesive layer was softened by pasting the above adhesive sheet on the entire surface of the resist pattern on this silicon wafer and heating it on a hot plate at 80 ° C. for 1 minute to heat it. After the state, it was returned to room temperature (20 ° C.) and solidified. After that, when the adhesive sheet was peeled off, the resist material was peeled off integrally. When the surface of the silicon wafer was observed with a fluorescence microscope, no resist material adhered and remained on the surface of the wafer was observed.

[0022]

Example 2 Polyacrylic acid having a weight average molecular weight of 410,000 was dissolved in distilled water so that the concentration became 20% by weight, and this solution was made into a glass having a thickness of 80 μm and a density of 40 lines / inch in both length and width. The cloth was applied to a basis weight of 50 g / m ² to prepare an adhesive sheet. Distilled water was dropped onto the entire surface of a resist pattern formed on a silicon wafer by the method of Example 1 and having As ions implanted into the entire surface by a spoid so that the entire surface of the wafer was spread. Then, the wafer was heated on a hot plate at 100 ° C. for 5 minutes in this state to dry the distilled water to solidify the polyacrylic acid and then return to room temperature (20 ° C.). After that, when the adhesive sheet was peeled off, the resist material was peeled off integrally. When the surface of the silicon wafer was observed with a fluorescence microscope, no resist material adhered and remained on the surface of the wafer was observed.

Example 3 The adhesive sheet produced in Example 2 was brought into contact with the entire surface of a resist pattern formed on a silicon wafer by the method of Example 1 and implanted with As ions on the entire surface. Steam from above using a steam iron heated to 120 ° C
The wafer at 100 ℃
It was put on the hot plate of No. 5 for 5 minutes to dry the water to solidify the polyacrylic acid, and then the temperature was returned to room temperature (20 ° C.). After that, when the adhesive sheet was peeled off, the resist material was peeled off integrally. When the surface of the silicon wafer was observed with a fluorescence microscope, no resist material adhered and remained on the surface of the wafer was observed.

Example 4 A methanol was dropped by a void onto the entire surface of a resist pattern formed on a silicon wafer by the method of Example 1 and having As ions implanted into the entire surface thereof, so that it spreads over the entire wafer. Then, the adhesive sheet prepared in Example 1 is brought into contact with the wafer, and in this state, the wafer is placed on a hot plate at 100 ° C. for 5 minutes to heat it to dry the methanol and solidify the polymer. After that, the temperature was returned to room temperature (20 ° C.). After that, when the adhesive sheet was peeled off, the resist material was peeled off integrally. When the surface of the silicon wafer was observed with a fluorescence microscope, no resist material adhered and remained on the surface of the wafer was observed.

Comparative Example 1 The adhesive sheet prepared in Example 1 was placed on the entire surface of a resist pattern formed on a silicon wafer by the method of Example 1 and implanted with As ions, at room temperature (20 ° C.). I attached it using a hand roller below. After that, when the adhesive sheet was peeled off, the resist material was not peeled at all.

[0027]

Comparative Example 2 The adhesive sheet prepared in Example 2 was applied to the entire surface of a resist pattern formed on a silicon wafer by the method of Example 1 and implanted with As ions on the entire surface at room temperature (20 ° C.). I attached it using a hand roller below. After that, when the adhesive sheet was peeled off, the resist material was not peeled at all.

[0029]

As described above, according to the resist removing method of the present invention, the unnecessary resist material on the article can be surely removed by a simple method.
In addition, it can be used in various fields such as liquid crystal.

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-6-252041 (JP, A) JP-A-6-37010 (JP, A) JP-A-6-267893 (JP, A) JP-A-6- 196398 (JP, A) JP 6-232040 (JP, A) JP 6-151301 (JP, A) JP 7-66102 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03F 7/42 H01L 21/027 C09J 7/02

Claims (4)

(57) [Claims] 1. An article on which a resist pattern is present,
Provide a layer made of an adhesive, in a method of removing the resist to integrally peel off the layer and the resist material, prior to the peeling, as an adhesion imparting treatment for changing the layer made of an adhesive from a softened state to a solidified state , Adhesive layer made of adhesive
Softening by heating above the glass transition temperature of the polymer
The glass transition temperature of the polymer above.
A method of removing a resist, characterized in that the adhesiveness of this layer to a resist material is enhanced by performing a process of cooling to a solidified state . 2. An article on which a resist pattern is present,
An adhesive layer is provided, and this layer and the resist material are integrated.
In the method of removing the resist that peels off,
Prior to this, the adhesive layer was changed from the softened state to the solidified state.
As an adhesion imparting treatment for reduction, after a layer made of the adhesive was softened and swelled or dissolved with water or solvent, the process of the solidification state of water or solvent and dried removed
To improve the adhesion of this layer to the resist material.
A method for removing a resist, which is characterized by the above . 3. The method for removing a resist according to claim 1, wherein the layer made of an adhesive is reinforced by a base material. 4. The method for removing a resist according to claim 3 , wherein the substrate is porous.