KR102397091B1 - Resist stripper composition and a method of stripping resist using the same - Google Patents

Abstract

The present invention relates to a resist stripper composition comprising a tetraalkyl ammonium hydroxide compound, an amine compound, a nonionic surfactant and water, and a resist stripping method using the same, which can remove a modified resist and particulate impurities, It has the effect of not damaging the resist lower layer.

Description

Resist stripper composition and a method of stripping resist using the same

The present invention relates to a resist stripper composition and a resist stripping method using the same, and more particularly, to a resist stripper composition comprising a tetraalkyl ammonium hydroxide compound, an amine compound, a nonionic surfactant and water, and a resist stripping method using the same It relates to a peeling method.

A photoresist is a material essential for a photolithography process, and the photolithography process includes an integrated circuit (IC), a large scale integration (LSI), a very large scale It is one of the processes generally used for manufacturing semiconductor devices such as integration (VLSI) and the like and image realization devices such as liquid crystal display (LCD) and plasma display device (PDP).

The photo-resist is a chemical film that can shape a micro-pattern drawn in advance on a photomask on a desired substrate using a photochemical reaction by light, and is a polymer applied to exposure technology together with a photomask. As a material, it is recognized as a major factor that directly affects the degree of integration of a device and determines the ultimate resolution limit. According to the so-called Moore's law (the theory that the density of semiconductors doubles every two years), in order to put the circuit density, which increases every year, into a semiconductor of a limited size, the designed circuit must be patterned smaller. The increase in semiconductor density inevitably requires the development of new photoresists constantly.

A photolithography process for forming fine wiring on a substrate using such a photoresist is generally used, which uses the thermal, mechanical, and chemical properties of the photoresist to apply the photoresist to the substrate and then exposes it to light of a certain wavelength. (exposure) and performing dry or wet etching.

In a fine patterning technique using a photoresist, an important field along with the development of a new photoresist is a resist stripper (or Photoresist Remover). After the process is finished, the photoresist must be removed with a solvent called a stripper (or photoresist remover), which is an unnecessary photoresist layer after the etching process, and the metal residues or altered photoresist remaining on the substrate through the etching and washing processes. This is because resist residues cause problems such as lowering the yield of semiconductor manufacturing.

Accordingly, a significant level of peeling properties is required with respect to the removal power of the etching residue, the excellent peeling power of the altered photoresist residue, and the corrosion inhibiting power of the metal wiring.

Korean Patent Laid-Open No. 10-2005-0094409 discloses a resist stripper composition, but there is a problem in causing damage to the resist lower layer.

Republic of Korea Patent Publication No. 10-2005-0094409

An object of the present invention is to provide a resist stripper composition capable of removing particulate impurities and denatured resist generated by ions implanted to dope a semiconductor film during a semiconductor manufacturing process.

Another object of the present invention is to provide a resist stripper composition capable of minimizing damage to a silicon nitride layer or a silicon oxide layer that is a resist lower layer.

In order to achieve the above object,

The present invention provides a resist stripper composition comprising a tetraalkyl ammonium hydroxide compound represented by the following formula (1), an amine compound represented by the following formula (2), a nonionic surfactant, and water.

[Formula 1]

N(R ₁ ) ₄ ⁺ OH ^-

[Formula 2]

NH ₂ C ₂ H ₄ (NHC ₂ H ₄ ) _n NH ₂

Wherein R ₁ is a linear alkyl group having 2 to 4 carbon atoms,

Wherein n is an integer of 0 to 2.

In addition, the present invention comprises the steps of (1) depositing a semiconductor film on a substrate;

(2) forming a photoresist film on the semiconductor film;

(3) selectively exposing the photoresist film;

(4) forming a photoresist pattern by developing the photoresist film after the exposure;

(5) doping the semiconductor film on which the photoresist pattern is formed; and

(6) stripping the photoresist modified by the doping using the resist stripper composition of the present invention; provides a resist stripping method comprising a.

The resist stripper composition of the present invention can effectively remove particulate impurities and denatured resist generated by ions implanted to dope the semiconductor film.

In addition, the resist stripper composition of the present invention can minimize damage to the silicon nitride film or silicon oxide film that is the resist lower film.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a resist stripper composition comprising a tetraalkyl ammonium hydroxide compound represented by the following formula (1), an amine compound represented by the following formula (2), a nonionic surfactant, and water.

[Formula 1]

N(R ₁ ) ₄ ⁺ OH ^-

[Formula 2]

NH ₂ C ₂ H ₄ (NHC ₂ H ₄ ) _n NH ₂

Wherein R ₁ is a linear alkyl group having 2 to 4 carbon atoms,

Said n is an integer of 0-2.

The resist stripper composition of the present invention can remove a modified resist formed by ions implanted to dope (n-doping or p-doping) a semiconductor film during a semiconductor manufacturing process.

In more detail, a resist is applied on the semiconductor film, and then ion implantation is performed to dope the semiconductor film. During the ion implantation process, the doped material penetrates into the resist, thereby crosslinking the resist composition to form a modified resist, and particulate impurities are also generated. Dissolution becomes difficult due to the modified resist and particulate impurities, and thus it is difficult to peel the resist.

In addition, in the prior art, a problem in that a silicon oxide film or a silicon nitride film, which is an underlying film, is damaged when the resist is removed by including an oxidizing agent in the resist stripper composition.

Accordingly, in the present invention, it was intended to provide a resist stripper composition capable of removing the modified resist and not causing damage to the lower layer, and the resist stripper composition of the present invention is a tetraalkyl ammonium hydroxide compound of Formula 1 , an amine compound of Formula 2, a nonionic surfactant, and water.

The resist stripper composition of the present invention, the tetraalkyl ammonium hydroxide compound of Formula 1 below, serves to decompose and dissolve the denatured resist.

[Formula 1]

N(R ₁ ) ₄ ⁺ OH ^-

Wherein R ₁ is a linear alkyl group having 2 to 4 carbon atoms.

The tetraalkyl ammonium hydroxide compound of Formula 1 includes at least one selected from the group consisting of tetraethyl ammonium hydroxide, tetrapropyl ammonium hydroxide and tetrabutyl ammonium hydroxide, preferably tetraethyl ammonium hydroxide. and at least one selected from the group consisting of ammonium hydroxide and tetrabutyl ammonium hydroxide.

In addition, the tetraalkyl ammonium hydroxide compound of Formula 1 is included in an amount of 0.1 to 20 wt%, preferably 0.2 to 15 wt%, based on the total weight of the resist stripper composition of the present invention.

When the tetraalkyl ammonium hydroxide compound of Formula 1 is included in an amount of less than 0.1 wt%, the removal rate of the denatured resist is significantly reduced, and when it is included in an amount exceeding 20 wt%, the resist lower layer, that is, the semiconductor layer is damaged. There is this.

The amine compound of Formula 2, which is the resist stripper composition of the present invention, swells the modified resist to improve the removal rate, and serves to chelate and remove the generated particulate impurities.

[Formula 2]

NH ₂ C ₂ H ₄ (NHC ₂ H ₄ ) _n NH ₂

Wherein n is an integer of 0 to 2.

The amine compound of Formula 2 includes at least one selected from the group consisting of ethylenediamine, diethylenetriamine and triethylenetetraamine, preferably selected from the group consisting of diethylenetriamine and triethylenetetraamine including one or more of which

In addition, the amine compound of Formula 2 is included in an amount of 0.01 to 5 wt%, preferably 0.1 to 3 wt%, based on the total weight of the resist stripper composition of the present invention.

When the amine compound of Formula 2 is included in an amount of less than 0.01 wt%, the effect of improving the removal rate of the modified resist is insignificant, and when it exceeds 5 wt%, the removal rate of the modified resist is reduced.

The nonionic surfactant, which is the resist stripper composition of the present invention, serves to increase the rate of removal of the denatured resist by improving the wettability of the semiconductor film, which is the resist lower film.

The nonionic surfactant is selected from the group consisting of polyoxyethylene octyl phenyl ether, polyoxyethylene polyoxypropylene butyl ether, and polyoxyethylene nonylpheyl ether. At least one selected from the group consisting of polyethylene octylphenyl ether and polyoxyethylene polyoxypropylene butyl ether is preferably included.

The nonionic surfactant is included in an amount of 0.01 to 5 wt%, preferably 0.05 to 3 wt%, based on the total weight of the resist stripper composition of the present invention.

When the nonionic surfactant is included in an amount of less than 0.01% by weight, the effect of improving wettability is insignificant, and when it is included in an amount exceeding 5% by weight, a problem in which a large amount of foam is generated occurs.

The resist stripper composition of the present invention contains the remaining amount of water so that the total content of the resist stripper composition is 100% by weight, and the water is preferably deionized water.

The resist stripper composition of the present invention can provide excellent peeling force for the modified resist and particulate impurities formed by crosslinking between polymers by penetrating the doped material into the resist during the ion implantation process for doping the semiconductor film, and damage to the membrane can be prevented.

In addition, the method of use of the resist stripper composition of the present invention is not particularly limited, and the semiconductor film containing the modified resist and particulate impurities formed during the ion implantation process for doping the semiconductor film during the semiconductor manufacturing process is immersed in the stripper composition or , it can be used in a method such as applying the stripper composition to the substrate.

In addition, the present invention provides a resist stripping method characterized by using the resist stripping solution composition of the present invention. The above-mentioned resist peeling method,

(1) depositing a semiconductor film on a substrate;

(2) forming a photoresist film on the semiconductor film;

(3) selectively exposing the photoresist film;

(4) forming a photoresist pattern by developing the photoresist film after the exposure;

(5) doping the semiconductor film on which the photoresist pattern is formed; and

(6) removing the photoresist modified by the doping using the resist stripper composition of the present invention;

The semiconductor film includes at least one selected from the group consisting of a silicon film, a silicon oxide film, and a silicon nitride film.

Among the stripping methods, the resist film formation, exposure and development processes may be performed by methods commonly known in the art.

In the stripping, if the resist stripper composition and the substrate coated with the resist modified by doping can come into contact with each other, good stripping results can be obtained.

In addition, as the peeling method, a dipping method, a spraying method, or a dipping and spraying method may be used. In the case of peeling by dipping, spraying or immersion and spraying, as peeling conditions, the temperature is usually 10 to 100° C., preferably 20 to 80° C., and the dipping, spraying, or immersion and spraying time is usually 30 seconds to 40 minutes; It is preferably 1 minute to 20 minutes, but it is not strictly applied in the present invention, and can be easily and modified by those skilled in the art under suitable conditions.

When the temperature of the stripper composition applied on the resist-coated substrate is less than 10° C., the time required to remove the denatured resist film may be excessively long. In addition, when the temperature of the resist stripper composition exceeds 100° C., damage to the lower film layer of the resist film is concerned, and handling of the stripper is difficult.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are provided to explain the present invention in more detail, and the scope of the present invention is not limited by the following examples. The following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention.

< resist stripper Composition Preparation>

Example 1 to 11 and comparative example 1 to 6.

A resist stripper composition was prepared by mixing the components and contents shown in Table 1 below.

Unit: Weight % division hydroxide
compound amine compounds organic solvent nonionic
Surfactants Water (DIW) A-1 A-2 A-3 B-1 B-2 B-3 B-4 C-1 C-2 D-1 D-2 Example 1 15 - - 0.1 - - - - - 0.1 - remaining amount Example 2 - 15 - 0.1 - - - - - 0.1 - remaining amount Example 3 15 - - 3 - - - - - 0.1 - remaining amount Example 4 - 15 - - 3 - - - - - 0.1 remaining amount Example 5 15 - - 0.1 - - - - - One - remaining amount Example 6 - 15 - - 0.1 - - - - - One remaining amount Example 7 5 - - 0.5 - - - - - 0.1 - remaining amount Example 8 - 5 - - 0.5 - - - - - 0.1 remaining amount Example 9 15 - - - 0.1 - - - - 0.1 - remaining amount Example 10 10 - - 0.5 - - - - - - 0.1 remaining amount Example 11 - 10 - - 0.5 - - - - 0.1 - remaining amount Comparative Example 1 - - 15 0.1 - - - - - 0.1 - remaining amount Comparative Example 2 15 - - - - - - 0.1 - 0.1 - remaining amount Comparative Example 3 15 - - - - - - - 5 0.1 - remaining amount Comparative Example 4 15 - - - - 0.1 - - - 0.1 - remaining amount Comparative Example 5 15 - - - - - 0.1 - - 0.1 - remaining amount Comparative Example 6 15 - - 0.1 - - - - - - - remaining amount

A-1: tetraethylammonium hydroxide

A-2: tetrabutylammonium hydroxide

A-3: tetramethylammonium hydroxide

B-1: diethylenetriamine

B-2: triethylenetetraamine

B-3: monoethanolamine

B-4: Butylamine

C-1: Butyl acetate

C-2: N-methylpyrrolidone

D-1: polyethylene octylphenyl ether

D-2: polyoxyethylene polyoxypropylene butyl ether

Experimental example One. resist stripper Evaluation of the performance of the composition

One. detergency evaluation

A photoresist (193 nm) was applied on a silicon wafer, patterned through exposure and development, and then ions were implanted to prepare a doped silicon wafer.

The wafer was cut into a size of 2x2 cm, and the resist stripper compositions prepared in Examples 1 to 11 and Comparative Examples 1 to 6 were heated to 60° C., and then the wafer was immersed for 2 minutes and then washed with water.

The cleaned wafer was observed for removal of denatured resist and removal of particulate impurities using a scanning electron microscope (SEM, Hitachi S-4700) and an ellipsometer (SE-MG-1000).

The evaluation results are as follows, and the results are shown in Table 2 below.

<Evaluation of removal of modified resist>

◎ : Removed more than 95%

○ : 90% or more and less than 95% removed

△: 80% or more and less than 90% removed

Х: removed to less than 80%

<Evaluation of removal of particulate impurities>

◎ : Removed more than 95%

○ : 90% or more and less than 95% removed

△: 80% or more and less than 90% removed

Х: removed to less than 80%

2. oxide film and of nitride film damage assessment

A silicon oxide film (SiOx) and a silicon nitride film (SiN) were cut to a size of 2x2 cm, the resist stripper compositions prepared in Examples 1 to 11 and Comparative Examples 1 to 6 were heated to 60° C., and then the silicon oxide film and silicon nitride film were each immersed for 5 minutes and then washed with water.

The cleaned silicon oxide film and silicon nitride film were observed for film damage using a scanning electron microscope (SEM, Hitachi S-4700) and an ellipsometer (SE-MG-1000).

The evaluation results are as follows, and the results are shown in Table 2 below.

<Evaluation of silicon oxide film (SiOx) damage>

◎: silicon oxide film etch rate < 1 A/min

○ : 1 A/min ≤ Silicon oxide film etching rate < 5 A/min

△: 5 A/min ≤ silicon oxide film etching rate < 10 A/min

Х : Silicon oxide film etch rate ≥ 10 A/min

<Evaluation of silicon nitride (SiN) damage>

◎: silicon nitride film etch rate < 1 A/min

○ : 1 A/min ≤ Silicon nitride etching rate < 5 A/min

△: 5 A/min ≤ silicon nitride etching rate < 10 A/min

Х : Silicon nitride etching rate ≥ 10 A/min

3. Stability evaluation

Whether a color change occurred in the resist stripper compositions prepared in Examples 1 to 11 and Comparative Examples 1 to 6 was visually observed.

The evaluation results are as follows, and the results are shown in Table 2 below.

<solubility>

○: color change

X: No color change

division denaturalization
resist removal particulate
removal of impurities SiOx damage SiN damage color change Example 1 ◎ ◎ ◎ ◎ Х Example 2 ◎ ◎ ◎ ◎ Х Example 3 ○ ○ ◎ ◎ Х Example 4 ○ ○ ◎ ◎ Х Example 5 ○ ◎ ◎ ◎ Х Example 6 ◎ ◎ ◎ ◎ Х Example 7 ○ ◎ ◎ ◎ Х Example 8 ○ ◎ ◎ ◎ Х Example 9 ◎ ◎ ◎ ◎ Х Example 10 ◎ ◎ ◎ ◎ Х Example 11 ◎ ◎ ◎ ◎ Х Comparative Example 1 ◎ ◎ ○ △ Х Comparative Example 2 Х Х ◎ ◎ ○ Comparative Example 3 △ △ ◎ ◎ ○ Comparative Example 4 △ ○ ◎ ◎ X Comparative Example 5 △ ○ ◎ ◎ X Comparative Example 6 △ ○ ◎ ◎ X

Through the results in Table 2, it was confirmed that Examples 1 to 11, which are the resist stripper compositions of the present invention, were excellent in removing the modified resist and particulate impurities, did not damage the silicon oxide film and the silicon nitride film, and were stable. .

On the other hand, the resist stripper composition of Comparative Example 1 using a hydroxide compound not corresponding to the tetraalkyl ammonium hydroxide compound of Formula 1 was unstable, resulting in color change, and the amine compound of Formula 2 was not used. However, the resist stripper compositions of Comparative Examples 2 and 3 using an organic solvent did not effectively remove the modified resist and particulate impurities.

The resist stripper compositions of Comparative Examples 4 and 5 using an amine compound not corresponding to the amine compound of Formula 2 did not effectively remove the modified resist.

In addition, the resist stripper composition of Comparative Example 6, which did not contain the nonionic surfactant, did not effectively remove the modified resist.

Therefore, the resist stripper composition of the present invention exhibits excellent peeling power for the modified resist and particulate impurities formed by crosslinking between polymers as the doped material penetrates the resist during the ion implantation process for doping the semiconductor film, and the lower part of the resist It did not damage the membrane, and it was confirmed through the experiment that it was stable.

Claims (7)

A resist stripper composition comprising a tetraalkyl ammonium hydroxide compound of Formula 1 below, an amine compound of Formula 2 below, a nonionic surfactant, and water, and no organic solvent.
[Formula 1]
N(R ₁ ) ₄ ⁺ OH ^-
[Formula 2]
NH ₂ C ₂ H ₄ (NHC ₂ H ₄ ) _n NH ₂
Wherein R ₁ is a linear alkyl group having 2 to 4 carbon atoms,
Said n is an integer of 0-2. The method according to claim 1, wherein the tetra alkyl ammonium hydroxide compound of Formula 1 comprises at least one selected from the group consisting of tetra ethyl ammonium hydroxide, tetra propyl ammonium hydroxide and tetra butyl ammonium hydroxide. A resist stripper composition, characterized in that it. The resist stripper composition of claim 1, wherein the amine compound of Formula 2 comprises at least one selected from the group consisting of ethylenediamine, diethylenetriamine, and triethylenetetraamine. The resist stripping solution according to claim 1, wherein the nonionic surfactant comprises at least one selected from the group consisting of polyethylene octylphenyl ether, polyoxyethylene polyoxypropylene butyl ether, and polyoxyethylene nonylphenyl ether. composition. The method according to claim 1, Based on the total weight of the resist stripper composition, 0.1 to 20% by weight of the tetraalkyl ammonium hydroxide compound of Formula 1, 0.01 to 5% by weight of the amine compound of Formula 2, 0.01 to nonionic surfactant 5% by weight and the remaining amount of water so that the total weight of the resist stripper composition is 100% by weight. (1) depositing a semiconductor film on a substrate;
(2) forming a photoresist film on the semiconductor film;
(3) selectively exposing the photoresist film;
(4) forming a photoresist pattern by developing the photoresist film after the exposure;
(5) doping the semiconductor film on which the photoresist pattern is formed; and
(6) Peeling off the photoresist modified by the doping using the resist stripper composition of any one of claims 1 to 5; The method according to claim 6, wherein the semiconductor film comprises at least one selected from the group consisting of a silicon film, a silicon oxide film, and a silicon nitride film.