JPH09306809A - Formation of resist pattern and developing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a resist pattern and a developing apparatus which are capable of good resist patterning without increasing the installation cost and without decreasing the throughput in a resist process using an antireflection coating. SOLUTION: This method for manufacturing a semiconductor device includes a process for rotating a wafer, on whose surface a resist film is formed and an antireflection coating is formed on that resist film, and at the same time dissolving and removing this antireflection coating by dripping treatment solution for dissolving the antireflection coating on the surface of thereof, and a process for carrying out a developing treatment of this resist film after this antireflection coating removing treatment. This developing apparatus comprises a nozzle 4 in which holes for dripping the treatment solution and holes for dripping the developing solution for the resist film are alternately provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a resist process using an antireflection film. With the recent high integration of semiconductor devices, it has become necessary to form a fine pattern for a resist used in a semiconductor device manufacturing process, and it is important to control the dimensions of the resist pattern. Therefore, it is considered to use an antireflection film as a countermeasure.

By coating an antireflection film on a resist film, the reflection of light radiated from above on the resist film surface is suppressed, and the controllability of dimensions when forming a resist pattern is improved.

An antireflection film is spin-coated on a resist pattern, exposed, and resist-baked after exposure (Pos
After performing t Exposure Baking (abbreviated as PEB), the antireflection film is stripped using pure water or a positive resist developer (TMAH aqueous solution), but the number of steps is increased and the antireflection film is coated and stripped. There is a drawback that a device for use is also required.

In order to reduce these difficulties as much as possible,
At present, the antireflection film is peeled off and the resist is developed at the same time, so that the device is shared and the process is shortened. However, in order to improve the performance of the antireflection film, it is necessary to lower the refractive index, so it is necessary to increase the content of fluorine, but when the content of fluorine is increased, the water solubility deteriorates. Therefore, there is a problem that a hydrophilic substance must be added to increase the water solubility.

Under the circumstances as described above, there is a demand for a resist pattern forming method capable of reducing these problems as much as possible.

[0006]

2. Description of the Related Art A conventional resist pattern forming method will be described in detail with reference to FIG. FIG. 6 is a diagram showing the structure of a conventional developing device.

When a wafer having a resist film and an antireflection film formed on the surface thereof is developed by using such a developing device, the semiconductor substrate 5 is connected to the rotary shaft 12 of the developing device as shown in FIG. After being placed on the surface of the integral chuck 13 and vacuum-adsorbed, first, while rotating the chuck 13, pure water is dropped from the pure water nozzle 14a to dissolve and peel off the antireflection film, and then development is performed. The resist film is developed by dropping the developing solution from the solution nozzle 14b.

Most of the antireflection films currently on the market are water-soluble ones using water as a solvent and can be easily peeled off with pure water or a developer for positive resist.
The peeling of the antireflection film can be performed before developing the resist by slightly lengthening the pre-wetting time in the normal developing process, so that it is possible to share a cup as an apparatus.

However, in the case of i-line exposure, in order to improve the performance of the antireflection film, the current refractive index n = 1.41.
It is necessary to reduce the degree to an ideal refractive index n = 1.3, and for that purpose, it is necessary to increase the content of fluorine, but if the content of fluorine is increased, the water solubility becomes poor. Therefore, it is necessary to add a hydrophilic substance to increase the water solubility.

[0010]

In the conventional method of forming a resist pattern described above, the water-soluble antireflection film can be stripped by pure water or a developer, but the refractive index is set to an ideal value. In order to do so, it is necessary to increase the content of fluorine, but increasing the content of fluorine deteriorates the water solubility, so a hydrophilic substance is added to increase the water solubility. As shown in FIG. 3 (a), the hydrophilic substance volatilizes from the antireflection film due to heating in the PEB process. Further, as shown in FIG. 3 (b), in the resist stripping process using pure water, only the hydrophilic substance is dissolved in pure water from the antireflection film, and the antireflection film is stripped as shown in FIG. 3 (c). Since the hydrophilic substance disappears and the remaining antireflective film has a strong water repellency, the water and the development process are performed as shown in FIG. 3 (c). There is a problem that the liquid does not spread over the entire surface and becomes a water drop, and as shown in FIG. 4, only the portion where the developing liquid was present is patterned.

The base resin of the antireflection film has a pH of 2
Since it has a strong acidity of ~ 3, it dissolves in an alkaline aqueous solution, so it is possible to carry out sudden development without peeling off the antireflection film. Ideally, the antireflection film should be removed first.

When an antireflection film having good water solubility is used, the antireflection film does not remain on the surface of the resist film, so that the resist film is correctly developed and an accurate resist film pattern is formed, but the water solubility is poor. When an antireflection film is used,
As shown in (a), the antireflection film 7 remains on the surface of the resist 6, and the resist 6 in the portion to be developed remains without being developed, and an accurate resist film pattern is not formed, resulting in defective development. There was a problem, and the resist 6 in the region where the antireflection film partially remained was not developed as shown in FIG. 5 (b).

In order to prevent the occurrence of such defective development, it is considered that the antireflection film is peeled off by using a dedicated peeling solution when the treatment is carried out by four steps of exposure → PEB → peeling → development. However, in order to use a dedicated stripping solution,
It was necessary to newly install equipment equipped with a cup dedicated to peeling, which resulted in increased equipment cost and reduced throughput.

Under the circumstances as described above, the present invention provides a resist pattern forming method and a developing device capable of performing good resist film patterning without increasing equipment costs and decreasing throughput. It is intended for.

[0015]

According to the method of forming a resist pattern of the present invention, a surface of a resist film is formed on a surface of a resist film and an antireflection film formed on the surface of the resist film while rotating the wafer. A step of dropping a treatment liquid that dissolves the antireflection film on the substrate to dissolve and peel the antireflection film; and a step of developing the resist film after the peeling treatment of the antireflection film is completed. To configure.

The developing device of the present invention comprises a nozzle in which the holes for dropping the processing liquid and the holes for dropping the developing liquid of the resist film are alternately arranged. That is, the present invention comprises a nozzle in which a hole for dropping a processing liquid for dissolving the antireflection film for dissolving and peeling the antireflection film and a hole for dropping the developing solution for the resist film are alternately arranged. First, the treatment liquid is dropped onto the surface of the antireflection film by using a developing device to remove the antireflection film, and the treatment liquid is switched to the development liquid for the resist film to develop the resist film. Therefore, it is possible to accurately pattern the resist film by preventing the antireflection film from remaining on the surface of the resist film.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a diagram showing a structure of a developing device according to one embodiment of the present invention, and FIG. 2 is a diagram showing a resist pattern formed by a resist pattern forming method according to one embodiment of the present invention.

The semiconductor substrate used in one embodiment of the present invention is H
It is a Bare silicon wafer that has been subjected to MDS processing, and the resist film is a positive resist having a film thickness of 7,500 Å. The antireflection film is an antireflection film manufactured by Japan Synthetic Rubber Co., Ltd., and the film thickness is 650
Å.

The pre-baking treatment after applying the resist to the semiconductor substrate was performed at 90 ° C. for 90 seconds, and the pre-baking treatment after applying the antireflection film was performed at 90 ° C. for 30 seconds. I-line is used as exposure light, NA is 0.57, σ is 0.60, PEB
Was performed at 110 ° C. for 60 seconds.

As shown in FIG. 1, the developing device of one embodiment according to the present invention uses a nozzle having a structure as shown in FIG. 1 (b) instead of the nozzle for the developing solution of the conventional developing device.
As shown in the figure, the nozzle 4 is provided with a main introduction path 4a for the first liquid.
A hole through which the introduction path 4b branches off and liquid is dripped at the lower end of the introduction path 4b.
4c is formed, and from the main introduction passage 4d for the second liquid to the introduction passage
4e is branched and a hole 4f for dropping the liquid is formed at the lower end of the introduction path 4e.

The holes 4c and 4f have a diameter of 1 mm, the introduction passages 4b and 4e have a diameter of 2 mm, and the main introduction passages 4a and 4d have a diameter of 5 mm. If the developing solution is supplied to the main introduction path 4d, it is possible to switch the solution to the developing solution and supply it immediately after the antireflection film is removed by the removing solution.

When a wafer having a resist film and an antireflection film on its surface is developed by using such a developing device, the semiconductor substrate 5 is placed on the rotary shaft 2 of the developing device as shown in FIG. After being placed on the surface of the chuck 3 having an integral structure and vacuum-adsorbed, first, while rotating the chuck 3 at 1,000 rpm, a 1% aqueous solution of TMAH is dropped from the hole 4c of the nozzle 4 for 30 seconds to form an antireflection film. After dissolution and peeling, the antireflection film was completely peeled and removed, then the antireflective film stripping solution was stopped, and the stripping solution was spun off by rotating at 3,000 rpm for 30 seconds, then 2.38% of TMAH The resist film is developed by switching to an aqueous solution and dropping the developing solution from the hole 4f.

After the development process is completed, pure water is dropped from a pure water nozzle similar to that of a conventional developing device (not shown) to wash the pure water, thus completing the developing process. When the developing device of the present invention was used to develop the resist film after removing the antireflection film by the method of forming a resist pattern of the present invention, accurate patterning became possible as shown in FIG.

[0024]

As is clear from the above description, according to the present invention, the peeling of the antireflection film and the development of the resist film can be continuously performed by the developing device equipped with the nozzle having an extremely simple structure. Therefore, in the resist process using the antireflection film, there is an advantage that it is possible to suppress the addition of equipment without increasing the number of steps, and a method of forming a resist pattern that can be expected to have a significant economic and reliability improvement effect, and It is possible to provide a developing device.

[Brief description of drawings]

FIG. 1 is a diagram showing the structure of a developing device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a resist pattern formed by a resist pattern forming method according to an embodiment of the present invention.

FIG. 3 is a diagram showing a first problem of the conventional technique.

FIG. 4 is a view showing a resist pattern formed by a conventional resist pattern forming method.

FIG. 5 is a diagram showing a second problem of the conventional technique.

FIG. 6 is a diagram showing a structure of a conventional developing device.

[Explanation of symbols]

 1 cup 2 rotating shaft 3 chuck 4 nozzle 4a main introduction path 4b introduction path 4c hole 4d main introduction path 4e introduction path 4f hole 5 semiconductor substrate 6 resist 7 antireflection film 8 hydrophilic substance

Claims (3)

[Claims] 1. A treatment liquid for dissolving the antireflection film is dropped onto the surface of the antireflection film while rotating a wafer having a resist film on the surface and an antireflection film formed on the surface of the resist film. A method of forming a resist pattern, comprising: a step of dissolving and peeling the antireflection film; and a step of developing the resist film after completion of the peeling treatment of the antireflection film. 2. The method for forming a resist pattern according to claim 1, wherein the treatment liquid is a low concentration TMAH aqueous solution. 3. A developing device comprising: a nozzle in which holes for dropping the processing liquid and holes for dropping the developing solution for the resist film are alternately arranged.